about summary refs log blame commit diff stats
path: root/apps/desugar.subx
blob: a2ce496e55e428140db7a8de87d6c6c353feffb6 (plain) (tree)
1
2
3
4
5
6
7
8
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260


                                
                                                


                   
                                                


                   









                                                        









                                                                                    







                                                                                                                                                 
                                     

                       
                                                                                                                                                                       




                                                                                                                                                                  
                                                  






















                                                                                                                                                                                      
                            
                   




                           
                                                                                                                                                                  





                                

                                                                              
                                                                                 




                                      
                                                                       
                    
                                                          
                                                                       
                   
                                                                   
                      


                                                                         


                                                                            
                                                         





                                                   

















                                                                                                                                                                         
                   














                                                                                                                                                                     




                                                                                                                                                                    
                                               



                   
                                           

                                                                                                                                                                  
                
                                         






                                                                                                                                                                  
                           
                               










                                                                                                                                                                               
                               

                                                               
                                                                
                     













































                                                                                                                                                                     
                                       
                   
                                                                                                                                                                      

               
                                    
                      
                                                                                                                                                                  
              
                                      


                                                               
                                                                   
                       











                                                                                                                                                                  
                                                       
                   
               
               


                                                                                                                                                                      


                                      





                                                                                                                                                                  

                                      







                                                          

















                                                                                                                                                                      

                                                                                                                                                                  
                                      

                               
                   
                          

                                                                                                                                                                      
                                  

                                                                                                                                                                  

                                      




















                                                                                                                                                                       






















































                                                                                                                                                                  











































































































































































































                                                                                                                                                                       
                         
                                                                          



                                                                                                                                                                       
               




                                                                                                                                                                            

                                                          
                              
                             
                                                                                                                                                                     
                            
              
                             
                      
                                                                                                                                                                  



                                                                                                                                                                      
              
                                  

                                                                                                                                                                  



                                                                                                                                                                      
              
                                        

                                                                                                                                                                  



                                                                                                                                                                      
              
                                  

                                                                                                                                                                  
                      
                         
                 



                                                                                                                                                                       
 
                      


                                                                                                                                                                       
















                                                                                                                                                                  

                                


                                                                                                                                                                             
                        


                                                                                                                                                                       
                                                       

                                             
               
              
                                    
                      
                                                                                                                                                                
                                         
                   
































                                                                                                                                                                     
                                                

                                                 
              
                                      

                                                                                                                                                                  




                                                                                                                                                                       
                        



















                                                                                                                                                                       

                                


                                                                                                                                                                             
                        


                                                                                                                                                                       
                                                           

                                             
               
              
                                    
                      
                                                                                                                                                                
                                         
                   
                                             
              






























                                                                                                                                                                     
                                                



                                                 





                                                                                                                                                                       
 










                                                                                                                                                                       


























































































                                                                                                                                                                                          

                             












































































































































































































































































































































                                                                                                                                                                                







                                                                                                                                                                       
                                                         



                                                                                    
                         
                                                                                              
































                                                             




                                                                                                                                                                       
               
                
                                                                                                                                                                            
                               
                                                                                                                                                                      
                         

                                                                


                                    

                                                       



                                                                                                                                                                               
                                                                        












                                                                                                                                                                  
                                                                                                                                                                        


                                               

                                                                                                                                                                      
                     









                                                                                                                                                                        
                             








                                                                                                                                                                        






















                                            
                             

                                                                                                                                                                       
                         
                 





                                                                                                                                                                       







































                                                                                                                                                                            
























































                                                                                                                                                                             





























































                                                                                                                                                                             




                                                                                                                                                                       







                                                              



                                                                                                       
                                                                                                      


                                                                                                                                                                       


                                            
                                                                                                                                                                     



                                                                                                                                                                  
                                     
                   
                                                                                                                                                                      
                                                                                                                                                                     






                                                                                                                                                                  
                                                                                                                                                                     




                                                                                                                                                                  

























                                                                                                                                                                       





                                                                     
                                             


                                      
                                                                                                                                                                  



































































                                                                                                                                                                       





                                                                     
                                             


                                      
                                                                                                                                                                  


































                                                                                                                                                                     
                                                  










                                                                                                                                                                       

                          










































































                                                                                                                                                                              
                                          

                                                    
                    















































                                                                                                                                                                       
                                          

                                                                   
                    







































                                                                                                                                                                        
                                                        

                                                                          
                    


























                                                                                                                                                                             
                            
                                                                                                                                                                            
                                                                                      









                                                                                                                                                                               



























                                                                                                                                                                             
                                                            

                                                             
                    




























                                                                                                                                                                             
                                                            

                                                                            
                    












































                                                                                                                                                                             
















                                
# Desugar a few kinds of syntax.
#
# 1.
#   $ echo "ab %eax"  |  ./subx run apps/desugar
#   ab 3/mod 0/rm32
#
# 2.
#   $ echo "ab *eax"  |  ./subx run apps/desugar
#   ab 0/mod 0/rm32
#
# 3.
#   $ echo "ab *(eax+4)"  |  ./subx run apps/desugar
#   ab 2/mod 0/rm32 4/disp32
#
# 4.
#   $ echo "ab *(eax+ecx)"  |  ./subx run apps/desugar
#   ab 0/mod 4/rm32 0/base 1/index 0/scale
#
# 5.
#   $ echo "ab *(eax+ecx+4)"  |  ./subx run apps/desugar
#   ab 2/mod 4/rm32 0/base 1/index 0/scale 4/disp32
#
# 6.
#   $ echo "ab *(eax+ecx<<2+4)"  |  ./subx run apps/desugar
#   ab 2/mod 4/rm32 0/base 1/index 2/scale 4/disp32
#
# Addition isn't commutative here. Template must always be (base+index<<scale+disp),
# though some components are optional as described above.
#
# No metadata allowed inside '*(...)'.
# Whitespace inside '*(...)' is ok.

== code
#   instruction                     effective address                                                   register    displacement    immediate
# . op          subop               mod             rm32          base        index         scale       r32
# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes

Entry:  # run tests if necessary, convert stdin if not
    # initialize heap
    # . Heap = new-segment(Heap-size)
    # . . push args
    68/push  Heap/imm32
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Heap-size/disp32                  # push *Heap-size
    # . . call
    e8/call  new-segment/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP

    # run tests if necessary, convert stdin if not
    # . prolog
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # - if argc > 1 and argv[1] == "test", then return run_tests()
    # . argc > 1
    81          7/subop/compare     1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0/disp8         1/imm32           # compare *EBP
    7e/jump-if-lesser-or-equal  $run-main/disp8
    # . argv[1] == "test"
    # . . push args
    68/push  "test"/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  kernel-string-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . check result
    3d/compare-EAX-and  1/imm32
    75/jump-if-not-equal  $run-main/disp8
    # . run-tests()
    e8/call  run-tests/disp32
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/EBX   Num-test-failures/disp32          # copy *Num-test-failures to EBX
    eb/jump  $main:end/disp8
$run-main:
    # - otherwise convert stdin
    # convert(Stdin, Stdout)
    # . . push args
    68/push  Stdout/imm32
    68/push  Stdin/imm32
    # . . call
    e8/call  convert/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x8/imm32         # add to ESP
    # . syscall(exit, 0)
    bb/copy-to-EBX  0/imm32
$main:end:
    b8/copy-to-EAX  1/imm32/exit
    cd/syscall  0x80/imm8

# error messages considered:
#   *x + 34                 -> error: base+disp addressing must be within '()'
convert:  # in : (address buffered-file), out : (address buffered-file) -> <void>
    # pseudocode:
    #   var line = new-stream(512, 1)
    #   while true
    #     clear-stream(line)
    #     read-line-buffered(in, line)
    #     if (line->write == 0) break                     # end of file
    #     while true
    #       var word-slice = next-word-or-expression(line)
    #       if slice-empty?(word-slice)                   # end of line
    #         break
    #       if slice-starts-with?(word-slice, "#")        # comment
    #         continue
    #       if slice-starts-with?(word-slice, '%')        # direct mode
    #         emit-direct-mode(word-slice, out)
    #       else if slice-starts-with?(word-slice, '*')   # indirect mode
    #         base, index, scale, disp = parse-effective-address(word-slice)
    #         emit-indirect-mode(out, base, index, scale, disp)
    #       else if slice-starts-with?(word-slice, '+')
    #         abort("'+' only permitted within '*(...)'")
    #       else
    #         write-slice-buffered(out, word-slice)
    #       write(out, " ")
    #     write(out, "\n")
    #   flush(out)
    #
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    50/push-EAX
    51/push-ECX
    52/push-EDX
    53/push-EBX
    # var line/ECX : (address stream byte) = stream(512)
    81          5/subop/subtract    3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x200/imm32       # subtract from ESP
    68/push  0x200/imm32/length
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # var word-slice/EDX = {0, 0}
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    2/rm32/EDX    .           .             .           4/r32/ESP   .               .                 # copy ESP to EDX
$convert:line-loop:
    # clear-stream(line)
    # . . push args
    51/push-ECX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # read-line-buffered(in, line)
    # . . push args
    51/push-ECX
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  read-line-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
$convert:check0:
    # if (line->write == 0) break
    81          7/subop/compare     0/mod/indirect  1/rm32/ECX    .           .             .           .           .               0/imm32           # compare *ECX
    0f 84/jump-if-equal  $convert:break/disp32
$convert:word-loop:
    # next-word-or-expression(line, word-slice)
    # . . push args
    52/push-EDX
    51/push-ECX
    # . . call
    e8/call  next-word-or-expression/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
$convert:check1:
    # if (slice-empty?(word-slice)) break
    # . EAX = slice-empty?(word-slice)
    # . . push args
    52/push-EDX
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . if (EAX != 0) break
    3d/compare-EAX-and  0/imm32
    0f 85/jump-if-not-equal  $convert:next-line/disp32
$convert:check-for-comment:
    # if (slice-starts-with?(word-slice, "#")) continue
    # . start/EBX = word-slice->start
    8b/copy                         0/mod/indirect  2/rm32/EDX    .           .             .           3/r32/EBX   .               .                 # copy *EDX to EBX
    # . c/EAX = *start
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    8a/copy-byte                    0/mod/indirect  3/rm32/EBX    .           .             .           0/r32/AL    .               .                 # copy byte at *EBX to AL
    # . if (EAX == '#') continue
    3d/compare-EAX-and  0x23/imm32/hash
    74/jump-if-equal  $convert:word-loop/disp8
$convert:check-for-direct-mode:
    # if (!slice-starts-with?(word-slice, "%")) goto next check
    3d/compare-EAX-and  0x25/imm32/percent
    75/jump-if-not-equal  $convert:check-for-indirect-mode/disp8
$convert:direct-mode:
#?     # dump word-slice {{{
#?     # . write(2/stderr, "w: ")
#?     # . . push args
#?     68/push  "w: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . clear-stream(Stderr+4)
#?     # . . save EAX
#?     50/push-EAX
#?     # . . push args
#?     b8/copy-to-EAX  Stderr/imm32
#?     05/add-to-EAX  4/imm32
#?     50/push-EAX
#?     # . . call
#?     e8/call  clear-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # . . restore EAX
#?     58/pop-to-EAX
#?     # . write-slice-buffered(Stderr, word-slice)
#?     # . . push args
#?     52/push-EDX
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-slice-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # emit-direct-mode(word-slice, out)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    52/push-EDX
    # . . call
    e8/call  emit-direct-mode/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # continue
    e9/jump  $convert:next-word/disp32
$convert:check-for-indirect-mode:
    # if (!slice-starts-with?(word-slice, "*")) goto next check
    3d/compare-EAX-and  0x2a/imm32/asterisk
    75/jump-if-not-equal  $convert:check-for-invalid-addition/disp8
$convert:indirect-mode:
    # spill registers
    50/push-EAX
    51/push-ECX
    52/push-EDX
    53/push-EBX
    # base/EAX, index/ECX, scale/EDX, disp/EBX = parse-effective-address(word-slice)
    # . . push args
    52/push-EDX
    # . . call
    e8/call  parse-effective-address/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # emit-indirect-mode(out, base, index, scale, disp)
    # . . push args
    53/push-EBX
    52/push-EDX
    51/push-ECX
    50/push-EAX
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  emit-indirect-mode/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x14/imm32        # add to ESP
    # restore registers
    5b/pop-to-EBX
    5a/pop-to-EDX
    59/pop-to-ECX
    58/pop-to-EAX
    # continue
    e9/jump  $convert:next-word/disp32
$convert:check-for-invalid-addition:
    # if (slice-starts-with?(word-slice, "+")) goto error1
    3d/compare-EAX-and  0x2b/imm32/plus
    74/jump-if-equal  $convert:error1/disp8
$convert:check-for-invalid-left-shift:
    # if (slice-starts-with?(word-slice, "<")) goto error1
    3d/compare-EAX-and  0x3c/imm32/less-than
    74/jump-if-equal  $convert:error1/disp8
$convert:regular-word:
    # write-slice-buffered(out, word-slice)
    # . . push args
    52/push-EDX
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  write-slice-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # fall through
$convert:next-word:
    # write-buffered(out, " ")
    # . . push args
    68/push  " "/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # loop
    e9/jump  $convert:word-loop/disp32
$convert:next-line:
    # write-buffered(out, "\n")
    # . . push args
    68/push  Newline/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # loop
    e9/jump  $convert:line-loop/disp32
$convert:break:
    # flush(out)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
$convert:end:
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x214/imm32       # add to ESP
    # . restore registers
    5b/pop-to-EBX
    5a/pop-to-EDX
    59/pop-to-ECX
    58/pop-to-EAX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

$convert:error1:
    # print(stderr, "error: '" EAX "' only permitted within '*(...)' in '" line "'")
    # . write-buffered(Stderr, "error: '")
    # . . push args
    68/push  "error: '"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-byte-buffered(Stderr, EAX)
    # . . push args
    50/push-EAX
    68/push  Stderr/imm32
    # . . call
    e8/call  write-byte-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-buffered(Stderr, "' only permitted within '*(...)' in '")
    # . . push args
    68/push  "' only permitted within '*(...)' in '"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-stream-data(Stderr, line)
    # . . push args
    51/push-ECX
    68/push  Stderr/imm32
    # . . call
    e8/call  write-stream-data/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-buffered(Stderr, "'")
    # . . push args
    68/push  "'"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . flush(Stderr)
    # . . push args
    68/push  Stderr/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . syscall(exit, 1)
    bb/copy-to-EBX  1/imm32
    b8/copy-to-EAX  1/imm32/exit
    cd/syscall  0x80/imm8
    # never gets here

test-convert-passes-most-words-through:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-input-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-input-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-output-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # initialize input
    # . write(_test-input-stream, "== abcd 0x1")
    # . . push args
    68/push  "== abcd 0x1"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # convert(_test-input-buffered-file, _test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    68/push  _test-input-buffered-file/imm32
    # . . call
    e8/call  convert/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check that the line just passed through
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # dump _test-output-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # . check-stream-equal(_test-output-stream, "== abcd 0x1 \n", msg)
    # . . push args
    68/push  "F - test-convert-passes-most-words-through"/imm32
    68/push  "== abcd 0x1 \n"/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-stream-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-convert-direct-mode:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-input-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-input-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-output-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # initialize input
    # . write(_test-input-stream, "ab %ecx")
    # . . push args
    68/push  "ab %ecx"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # convert(_test-input-buffered-file, _test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    68/push  _test-input-buffered-file/imm32
    # . . call
    e8/call  convert/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check that the line just passed through
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # dump _test-output-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # . check-stream-equal(_test-output-stream, "ab 3/mod/direct 0x00000001/rm32 \n", msg)
    # . . push args
    68/push  "F - test-convert-direct-mode"/imm32
    68/push  "ab 3/mod/direct 0x00000001/rm32 \n"/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-stream-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

# beware: modifies 'word'
emit-direct-mode:  # word : (address slice), out : (address buffered-file)
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    50/push-EAX
    # ++word->start
    # . EAX = word
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   8/disp8         .                 # copy *(EBP+8) to EAX
    # . ++(*EAX)
    ff          0/subop/increment   0/mod/indirect  0/rm32/EAX    .           .             .           .           .               .                 # increment *EAX
    # reg-num/EAX = get-slice(Registers, word, row-size=8)
    # . . push args
    68/push  "Registers"/imm32
    68/push  8/imm32/row-size
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    68/push  Registers/imm32
    # . . call
    e8/call  get-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x10/imm32        # add to ESP
    # write-buffered(out, "3/mod/direct ")
    # . . push args
    68/push  "3/mod/direct "/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # print-int32-buffered(out, *EAX)
    # . . push args
    ff          6/subop/push        0/mod/indirect  0/rm32/EAX    .           .             .           .           .               .                 # push *EAX
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  print-int32-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # write-buffered(out, "/rm32")
    # . . push args
    68/push  "/rm32"/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
$emit-direct-mode:end:
    # . restore registers
    58/pop-to-EAX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-emit-direct-mode:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-output-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # var slice/ECX = "%eax"
    b8/copy-to-EAX  "%eax"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # . ECX = {EAX, ECX}
    51/push-ECX
    50/push-EAX
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # emit-direct-mode(str, _test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    51/push-ECX
    # . . call
    e8/call  emit-direct-mode/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32         # add to ESP
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # dump output {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # check-stream-equal(_test-output-stream, "3/mod/direct 0/rm32", msg)
    # . . push args
    68/push  "F - test-emit-direct-mode/0"/imm32
    68/push  "3/mod/direct 0x00000000/rm32"/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-stream-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-emit-direct-mode-2:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-output-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # var slice/ECX = "%edi"
    b8/copy-to-EAX  "%edi"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # . ECX = {EAX, ECX}
    51/push-ECX
    50/push-EAX
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # emit-direct-mode(str/ECX, _test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    51/push-ECX
    # . . call
    e8/call  emit-direct-mode/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32         # add to ESP
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # dump output {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # check-stream-equal(_test-output-stream, "3/mod/direct 7/rm32", msg)
    # . . push args
    68/push  "F - test-emit-direct-mode/1"/imm32
    68/push  "3/mod/direct 0x00000007/rm32"/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-stream-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

# (re)compute the bounds of the next word or parenthetical expression in the line
# return empty string on reaching end of file
#
# error messages considered:
#   * ...                   -> error: no space after '*'
#   *(...                   -> error: *(...) expression must be all on a single line
next-word-or-expression:  # line : (address stream byte), out : (address slice)
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    50/push-EAX
    51/push-ECX
    56/push-ESI
    57/push-EDI
    # ESI = line
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
    # EDI = out
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           7/r32/EDI   0xc/disp8       .                 # copy *(EBP+12) to EDI
    # skip-chars-matching(line, ' ')
    # . . push args
    68/push  0x20/imm32/space
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  skip-chars-matching/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
$next-word-or-expression:check0:
    # if (line->read >= line->write) clear out and return
    # . EAX = line->read
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ESI+4) to EAX
    # . if (EAX < line->write) goto next check
    3b/compare                      0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # compare EAX with *ESI
    7c/jump-if-lesser  $next-word-or-expression:check-for-comment/disp8
    # . return out = {0, 0}
    c7          0/subop/copy        0/mod/direct    7/rm32/EDI    .           .             .           .           .               0/imm32           # copy to *EDI
    c7          0/subop/copy        1/mod/*+disp8   7/rm32/EDI    .           .             .           .           4/disp8         0/imm32           # copy to *(EDI+4)
    eb/jump  $next-word-or-expression:end/disp8
$next-word-or-expression:check-for-comment:
    # out->start = &line->data[line->read]
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+ECX+12 to EAX
    89/copy                         0/mod/indirect  7/rm32/EDI    .           .             .           0/r32/EAX   .               .                 # copy EAX to *EDI
    # if (line->data[line->read] != '#') goto next check
    # . EAX = line->data[line->read]
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/AL    0xc/disp8       .                 # copy byte at *(ESI+ECX+12) to AL
    # . compare
    3d/compare-EAX-and  0x23/imm32/pound
    75/jump-if-not-equal  $next-word-or-expression:check-for-paren/disp8
$next-word-or-expression:comment:
    # out->end = &line->data[line->write]
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy *ESI to EAX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  0/index/EAX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+EAX+12 to EAX
    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(EDI+4)
    # line->read = line->write  # skip rest of line
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy *ESI to EAX
    89/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(ESI+4)
    # return
    eb/jump  $next-word-or-expression:end/disp8
$next-word-or-expression:check-for-paren:
    # if (line->data[line->read] != '*') goto next check
    # . EAX = line->data[line->read]
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/AL    0xc/disp8       .                 # copy byte at *(ESI+ECX+12) to AL
    # . compare
    3d/compare-EAX-and  0x2a/imm32/asterisk
    75/jump-if-not-equal  $next-word-or-expression:regular-word/disp8
    # if (line->data[line->read] != '(') goto error1
    8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/AL    0xd/disp8       .                 # copy byte at *(ESI+ECX+12+1) to AL
    # . compare
    3d/compare-EAX-and  0x28/imm32/open-paren
    75/jump-if-not-equal  $next-word-or-expression:error1/disp8
$next-word-or-expression:paren:
    # skip-until-close-paren(line)
    # . . push args
    56/push-ESI
    # . . call
    e8/call  skip-until-close-paren/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # if (line->data[line->read] != ')') goto error2
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
    8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/AL    0xc/disp8       .                 # copy byte at *(ESI+ECX+12) to AL
    # . compare
    3d/compare-EAX-and  0x29/imm32/close-paren
    75/jump-if-not-equal  $next-word-or-expression:error2/disp8
    # skip ')'
    ff          0/subop/increment   1/mod/*+disp8   6/rm32/ESI    .           .             .           .           4/disp8         .                 # increment *(ESI+4)
    # fall through
$next-word-or-expression:regular-word:
    # skip-chars-not-matching-whitespace(line)  # including trailing newline
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  skip-chars-not-matching-whitespace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # out->end = &line->data[line->read]
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+ECX+12 to EAX
    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(EDI+4)
$next-word-or-expression:end:
    # . restore registers
    5f/pop-to-EDI
    5e/pop-to-ESI
    59/pop-to-ECX
    58/pop-to-EAX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

$next-word-or-expression:error1:
    # print(stderr, "error: no space allowed after '*' in '" line "'")
    # . write-buffered(Stderr, "error: no space allowed after '*' in '")
    # . . push args
    68/push  "error: no space allowed after '*' in '"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-stream-data(Stderr, line)
    # . . push args
    56/push-ESI
    68/push  Stderr/imm32
    # . . call
    e8/call  write-stream-data/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-buffered(Stderr, "'")
    # . . push args
    68/push  "'"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . flush(Stderr)
    # . . push args
    68/push  Stderr/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . syscall(exit, 1)
    bb/copy-to-EBX  1/imm32
    b8/copy-to-EAX  1/imm32/exit
    cd/syscall  0x80/imm8
    # never gets here

$next-word-or-expression:error2:
    # print(stderr, "error: no space allowed after '*' in '" line "'")
    # . write-buffered(Stderr, "error: *(...) expression must be all on a single line in '")
    # . . push args
    68/push  "error: *(...) expression must be all on a single line in '"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-stream-data(Stderr, line)
    # . . push args
    56/push-ESI
    68/push  Stderr/imm32
    # . . call
    e8/call  write-stream-data/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . write-buffered(Stderr, "'")
    # . . push args
    68/push  "'"/imm32
    68/push  Stderr/imm32
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . flush(Stderr)
    # . . push args
    68/push  Stderr/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . syscall(exit, 1)
    bb/copy-to-EBX  1/imm32
    b8/copy-to-EAX  1/imm32/exit
    cd/syscall  0x80/imm8
    # never gets here

test-next-word-or-expression:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # var slice/ECX = {0, 0}
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # write(_test-input-stream, "  ab")
    # . . push args
    68/push  "  ab"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # next-word-or-expression(_test-input-stream, slice)
    # . . push args
    51/push-ECX
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  next-word-or-expression/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(_test-input-stream->read, 4, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression/updates-stream-read-correctly"/imm32
    68/push  4/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(slice->start - _test-input-stream->data, 2, msg)
    # . check-ints-equal(slice->start - _test-input-stream, 14, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression: start"/imm32
    68/push  0xe/imm32
    # . . push slice->start - _test-input-stream
    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-input-stream/imm32 # subtract from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(slice->end - _test-input-stream->data, 4, msg)
    # . check-ints-equal(slice->end - _test-input-stream, 16, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression: end"/imm32
    68/push  0x10/imm32
    # . . push slice->end - _test-input-stream
    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-input-stream/imm32 # subtract from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-next-word-or-expression-returns-whole-comment:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # var slice/ECX = {0, 0}
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # write(_test-input-stream, "  # a")
    # . . push args
    68/push  "  # a"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # next-word-or-expression(_test-input-stream, slice)
    # . . push args
    51/push-ECX
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  next-word-or-expression/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(_test-input-stream->read, 5, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression-returns-whole-comment/updates-stream-read-correctly"/imm32
    68/push  5/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(slice->start - _test-input-stream->data, 2, msg)
    # . check-ints-equal(slice->start - _test-input-stream, 14, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression-returns-whole-comment: start"/imm32
    68/push  0xe/imm32
    # . . push slice->start - _test-input-stream
    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-input-stream/imm32 # subtract from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(slice->end - _test-input-stream->data, 5, msg)
    # . check-ints-equal(slice->end - _test-input-stream, 17, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression-returns-whole-comment: end"/imm32
    68/push  0x11/imm32
    # . . push slice->end - _test-input-stream
    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-input-stream/imm32 # subtract from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-next-word-or-expression-returns-empty-expression-on-eof:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # var slice/ECX = {0, 0}
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # write nothing to _test-input-stream
    # next-word-or-expression(_test-input-stream, slice)
    # . . push args
    51/push-ECX
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  next-word-or-expression/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(slice->end - slice->start, 0, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression-returns-empty-expression-on-eof"/imm32
    68/push  0/imm32
    # . . push slice->end - slice->start
    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
    2b/subtract                     0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract *ECX from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-next-word-or-expression-returns-whole-expression:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # var slice/ECX = {0, 0}
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # write(_test-input-stream, " *(a b)/imm32 ")
    # . . push args
    68/push  " *(a b)/imm32 "/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # next-word-or-expression(_test-input-stream, slice)
    # . . push args
    51/push-ECX
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  next-word-or-expression/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(slice->start - _test-input-stream->data, 1, msg)
    # . check-ints-equal(slice->start - _test-input-stream, 13, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression-returns-whole-expression: start"/imm32
    68/push  0xd/imm32
    # . . push slice->start - _test-input-stream
    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-input-stream/imm32 # subtract from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(slice->end - _test-input-stream->data, 13, msg)
    # . check-ints-equal(slice->end - _test-input-stream, 25, msg)
    # . . push args
    68/push  "F - test-next-word-or-expression-returns-whole-expression: end"/imm32
    68/push  0x19/imm32
    # . . push slice->end - _test-input-stream
    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-input-stream/imm32 # subtract from EAX
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

# Grammar:
#   *reg                    -> 0/mod reg/rm32
#   *(reg)                  -> 0/mod reg/rm32
#   *(reg+disp)             -> 2/mod reg/rm32 disp/disp32
#   *(reg1+reg2<<s)         -> 2/mod 4/rm32 reg1/base reg2/index s/scale 0/disp32
#   *(reg1+reg2<<s+disp)    -> 2/mod 4/rm32 reg1/base reg2/index s/scale disp/disp32
# Intermediate structure: base, index, scale, disp
# Default values: base: 0, index: 4 (none), scale: 0, disp: 0
# beware: modifies 'word'
parse-effective-address:  # word : (address slice) -> base/EAX, index/ECX, scale/EDX, disp/EBX
    # pseudocode:
    #   ++word->start to skip '*'
    #   initialize defaults: base=0, index=4, scale=0, disp=0
    #   if (*word->start != '(') {
    #     base = get-slice(Registers, word, row-size=8)
    #     return
    #   }
    #   # compound expressions
    #   skip whitespace
    #   read register into base
    #   skip whitespace
    #   if (*word->start == ')') goto end
    #   if (*word->start != '+') goto error2
    #   ++word->start to skip '+'
    #   skip whitespace
    #   read register into index
    #   skip whitespace
    #   if (*word->start == ')') goto end
    #   if (*word->start == '<') {
    #     ++word->start to skip '<'
    #     if (*word->start != '<') goto error3
    #     ++word->start to skip '<'
    #     skip whitespace
    #     read register into scale
    #     skip whitespace
    #     if (*word->start == ')') goto end
    #   }
    #   if (*word->start != '+') goto error4
    #   ++word->start to skip '+'
    #   skip whitespace
    #   read register into disp
    #   skip whitespace
    #   if (*word->start != ')') goto error5
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    56/push-ESI
    57/push-EDI
    # ESI = word
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
    # ++word->start to skip '*'
    ff          0/subop/increment   0/mod/indirect  6/rm32/ESI    .           .             .           .           .               .                 # increment *ESI
    # initialize defaults
    # base is in EDI; we'll move it to EAX just before we return
    bf/copy-to-EDI  0/imm32
    b9/copy-to-ECX  4/imm32/no-index
    ba/copy-to-EDX  0/imm32/.scale
    bb/copy-to-EBX  0/imm32/disp
$parse-effective-address:check-for-simple-register:
    # if (*word->start == '(') goto compound expression
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy *ESI to EAX
    8a/copy-byte                    0/mod/indirect  0/rm32/EAX    .           .             .           0/r32/AL    .               .                 # copy byte at *EAX to AL
    81          4/subop/and         3/mod/direct    0/rm32/EAX    .           .             .           .           .               0xff/imm32        # bitwise and of EAX
    3d/compare-EAX-and  0x28/imm32/open-paren
    74/jump-if-equal  $parse-effective-address:compound-expression/disp8
$parse-effective-address:simple-register:
    # base = get-slice(Registers, word, row-size=8)
    # . EAX = get-slice(Registers, word, row-size=8)
    # . . push args
    68/push  "Registers"/imm32
    68/push  8/imm32/row-size
    56/push-ESI
    68/push  Registers/imm32
    # . . call
    e8/call  get-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x10/imm32        # add to ESP
    # . base = *EAX
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           7/r32/EDI   .               .                 # copy *EAX to EDI
    # return
    eb/jump  $parse-effective-address:end/disp8
$parse-effective-address:compound-expression:
    # ++word->start to skip '('
    ff          0/subop/increment   0/mod/indirect  6/rm32/ESI    .           .             .           .           .               .                 # increment *ESI
    # skip whitespace
    # . EAX = skip-chars-matching-whitespace-in-slice(word->start, word->end)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/ESI    .           .             .           .           4/disp8         .                 # push *(ESI+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/ESI    .           .             .           .           .               .                 # push *ESI
    # . . call
    e8/call  skip-chars-matching-whitespace-in-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . word->start = EAX
    89/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy EAX to *ESI
    # read register into base
    # . EAX = next-register(word)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  next-register/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . EDI = *EAX
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           7/r32/EDI   .               .                 # copy *EAX to EAX
    # skip whitespace
    # if (*word->start == ')') goto end
    # if (*word->start != '+') goto error2
    # ++word->start
    # skip whitespace
    # read register into index
    # skip whitespace
    # if (*word->start == ')') goto end
    # if (*word->start == '<') {
    #   ++word->start to skip '<'
    #   if (*word->start != '<') goto error3
    #   ++word->start to skip '<'
    #   skip whitespace
    #   read register into scale
    #   skip whitespace
    #   if (*word->start == ')') goto end
    # }
    # if (*word->start != '+') goto error4
    # ++word->start to skip '+'
    # skip whitespace
    # read register into disp
    # skip whitespace
    # if (*word->start != ')') goto error5
$parse-effective-address:end:
    # return base in EAX
    89/copy                         3/mod/direct    0/rm32/EAX    .           .             .           7/r32/EDI   .               .                 # copy EDI to EAX
    # . restore registers
    5f/pop-to-EDI
    5e/pop-to-ESI
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

# assumes 'in' starts with a register name, and returns its code
# side-effect: modifies 'in' to scan past the initial register name
next-register:  # in : (address slice) -> reg/EAX : int
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    51/push-ECX
    56/push-ESI
    # ESI = in
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
    # var reg-slice/ECX : (address slice) = {in->start, in->start + 3}
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy *ESI to EAX
    05/add-to-EAX  3/imm32
    50/push-EAX
    ff          6/subop/push        0/mod/indirect  6/rm32/ESI    .           .             .           .           .               .                 # push *ESI
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # in->start += 3
    81          0/subop/add         0/mod/indirect  6/rm32/ESI    .           .             .           .           .               3/imm32           # add to *ESI
    # EAX = get-slice(Registers, word, row-size=8)
    # . . push args
    68/push  "next-register"/imm32
    68/push  8/imm32/row-size
    51/push-ECX
    68/push  Registers/imm32
    # . . call
    e8/call  get-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x10/imm32        # add to ESP
$next-register:end:
    # reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . restore registers
    5e/pop-to-ESI
    59/pop-to-ECX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-parse-effective-address-simple:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX = "*esi"
    b8/copy-to-EAX  "*esi"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # . ECX = {EAX, ECX}
    51/push-ECX
    50/push-EAX
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX, ECX, EDX, EBX = parse-effective-address(slice)
    # . . push args
    51/push-ECX
    # . . call
    e8/call  parse-effective-address/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # slice clobbered beyond this point
    # check-ints-equal(EAX, 6, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-simple/base"/imm32
    68/push  6/imm32/ESI
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(ECX, 4, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-simple/index"/imm32
    68/push  4/imm32/none
    51/push-ECX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(EDX, 0, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-simple/scale"/imm32
    68/push  0/imm32/none
    52/push-EDX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(EBX, 0, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-simple/displacement"/imm32
    68/push  0/imm32/none
    53/push-EBX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-parse-effective-address-base:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX = "*(esi  )"
    b8/copy-to-EAX  "*(esi  )"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # . ECX = {EAX, ECX}
    51/push-ECX
    50/push-EAX
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX, ECX, EDX, EBX = parse-effective-address(slice)
    # . . push args
    51/push-ECX
    # . . call
    e8/call  parse-effective-address/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # slice clobbered beyond this point
    # check-ints-equal(EAX, 6, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-base/base"/imm32
    68/push  6/imm32/ESI
    50/push-EAX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(ECX, 4, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-base/index"/imm32
    68/push  4/imm32/none
    51/push-ECX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(EDX, 0, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-base/scale"/imm32
    68/push  0/imm32/none
    52/push-EDX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # check-ints-equal(EBX, 0, msg)
    # . . push args
    68/push  "F - test-parse-effective-address-base/displacement"/imm32
    68/push  0/imm32/none
    53/push-EBX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

#? test-parse-effective-address-base-displacement:
#? 
#? test-parse-effective-address-base-index:
#? 
#? test-parse-effective-address-base-index-scale:
#? 
#? test-parse-effective-address-base-index-scale-displacement:

# Code generation:
#   if index is none and disp is 0, then mod = 0 and rm32 = base
#   if index is none, then mod = 2 and rm32 = base and disp32 = disp
#   if index is not none, then mod = 2 and rm32 = 4 and base = base and index = index and disp32 = disp
emit-indirect-mode:  # out : (address buffered-file), base : int, index : int, scale : int, disp : int
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # write-buffered(out, "0/mod/indirect ")
    # . . push args
    68/push  "0/mod/indirect "/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # print-int32-buffered(out, base)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  print-int32-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # write-buffered(out, "/rm32")
    # . . push args
    68/push  "/rm32"/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
$emit-indirect-mode:end:
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-emit-indirect-mode:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-output-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # emit-indirect-mode(_test-output-buffered-file, 0, 4/none, 0, 0)
    # . . write args
    68/push  0/imm32/.disp
    68/push  0/imm32/.scale
    68/push  4/imm32/.index/none
    68/push  0/imm32/.base
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  emit-indirect-mode/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x14/imm32        # add to ESP
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # dump output {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # check-stream-equal(_test-output-stream, "0/mod/indirect 0/rm32", msg)
    # . . push args
    68/push  "F - test-emit-indirect-mode/0"/imm32
    68/push  "0/mod/indirect 0x00000000/rm32"/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-stream-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-emit-indirect-mode-2:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-output-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-output-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # emit-indirect-mode(_test-output-buffered-file, 6, 4/none, 0, 0)
    # . . write args
    68/push  0/imm32/.disp
    68/push  0/imm32/.scale
    68/push  4/imm32/.index/none
    68/push  7/imm32/.base
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  emit-indirect-mode/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0x14/imm32        # add to ESP
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
#?     # dump output {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
#?     # }}}
    # check-stream-equal(_test-output-stream, "0/mod/indirect 7/rm32", msg)
    # . . push args
    68/push  "F - test-emit-indirect-mode/0"/imm32
    68/push  "0/mod/indirect 0x00000007/rm32"/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-stream-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

# update line->read to ')'
# line->read ends at ')'
skip-until-close-paren:  # line : (address stream)
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    50/push-EAX
    51/push-ECX
    52/push-EDX
    # ECX = line
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
    # EAX = skip-until-close-paren-in-slice(&line->data[line->read], &line->data[line->write])
    # . . push &line->data[line->write]
    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .                         2/r32/EDX   8/disp8         .                 # copy *(ECX+8) to EDX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    1/base/ECX  2/index/EDX   .           2/r32/EDX   0xc/disp8       .                 # copy ECX+EDX+12 to EDX
    52/push-EDX
    # . . push &line->data[line->read]
    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .                         2/r32/EDX   4/disp8         .                 # copy *(ECX+4) to EDX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    1/base/ECX  2/index/EDX   .           2/r32/EDX   0xc/disp8       .                 # copy ECX+EDX+12 to EDX
    52/push-EDX
    # . . call
    e8/call  skip-until-close-paren-in-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # line->read = EAX - line->data
    29/subtract                     3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # subtract ECX from EAX
    2d/subtract-from-EAX  0xc/imm32
    89/copy                         1/mod/*+disp8   1/rm32/ECX    .           .                         0/r32/EAX   4/disp8         .                 # copy EAX to *(ECX+4)
$skip-until-close-paren:end:
    # . restore registers
    5a/pop-to-EDX
    59/pop-to-ECX
    58/pop-to-EAX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-skip-until-close-paren:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . write(_test-input-stream, "*(abc) def")
    # .                   indices:  0123 45
    # . . push args
    68/push  "*(abc) def"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # precondition: line->read == 0
    # . . push args
    68/push  "F - test-skip-until-close-paren/precondition"/imm32
    68/push  0/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # skip-until-close-paren(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  skip-until-close-paren/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # check-ints-equal(line->read, 5, msg)
    # . . push args
    68/push  "F - test-skip-until-close-paren"/imm32
    68/push  5/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-skip-until-close-paren-ignores-spaces:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . write(_test-input-stream, "*(a b)/yz")
    # . . push args
    68/push  "*(a b)/yz"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # precondition: line->read == 0
    # . . push args
    68/push  "F - test-skip-until-close-paren-ignores-spaces/precondition"/imm32
    68/push  0/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # skip-until-close-paren(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  skip-until-close-paren/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # check-ints-equal(line->read, 5, msg)
    # . . push args
    68/push  "F - test-skip-until-close-paren-ignores-spaces"/imm32
    68/push  5/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-skip-until-close-paren-works-from-mid-stream:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . write(_test-input-stream, "0 *(a b)/yz")
    # . . push args
    68/push  "0 *(a b)/yz"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # precondition: _test-input-stream->read == 2
    c7          0/subop/copy        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         2/imm32           # copy to *(EAX+4)
    # skip-until-close-paren(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  skip-until-close-paren/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # check-ints-equal(_test-input-stream->read, 7, msg)
    # . . push args
    68/push  "F - test-skip-until-close-paren-works-from-mid-stream"/imm32
    68/push  7/imm32
    b8/copy-to-EAX  _test-input-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

skip-until-close-paren-in-slice:  # curr : (address byte), end : (address byte) -> new_curr/EAX
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    51/push-ECX
    52/push-EDX
    # ECX = curr
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
    # EDX = end
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         2/r32/EDX   0xc/disp8         .               # copy *(EBP+12) to EDX
    # EAX = 0
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    # skip initial dquote
    41/increment-ECX
$skip-until-close-paren-in-slice:loop:
    # if (curr >= end) break
    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
    73/jump-if-greater-unsigned-or-equal  $skip-until-close-paren-in-slice:break/disp8
    # AL = *curr
    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/AL    .               .                 # copy byte at *ECX to AL
$skip-until-close-paren-in-slice:check-close:
    # if (EAX == ')') break
    3d/compare-EAX-and  0x29/imm32/close-paren
    74/jump-if-equal  $skip-until-close-paren-in-slice:break/disp8
    # ++curr
    41/increment-ECX
    eb/jump  $skip-until-close-paren-in-slice:loop/disp8
$skip-until-close-paren-in-slice:break:
    # return curr
    89/copy                         3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy ECX to EAX
$skip-until-close-paren-in-slice:end:
    # . restore registers
    5a/pop-to-EDX
    59/pop-to-ECX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-skip-until-close-paren-in-slice:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup: (EAX..ECX) = "*(abc) def"
    b8/copy-to-EAX  "*(abc) def"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # EAX = skip-until-close-paren-in-slice(EAX, ECX)
    # . . push args
    51/push-ECX
    50/push-EAX
    # . . call
    e8/call  skip-until-close-paren-in-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(ECX-EAX, 5, msg)  # EAX is at the ')'
    # . . push args
    68/push  "F - test-skip-until-close-paren-in-slice"/imm32
    68/push  5/imm32
    # . . push ECX-EAX
    29/subtract                     3/mod/direct    1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract EAX from ECX
    51/push-ECX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-skip-until-close-paren-in-slice-ignores-spaces:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup: (EAX..ECX) = "*(a b)/yz"
    b8/copy-to-EAX  "*(a b)/yz"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # EAX = skip-until-close-paren-in-slice(EAX, ECX)
    # . . push args
    51/push-ECX
    50/push-EAX
    # . . call
    e8/call  skip-until-close-paren-in-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(ECX-EAX, 4, msg)  # EAX is at the ')'
    # . . push args
    68/push  "F - test-skip-until-close-paren-in-slice-ignores-spaces"/imm32
    68/push  4/imm32
    # . . push ECX-EAX
    29/subtract                     3/mod/direct    1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract EAX from ECX
    51/push-ECX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

test-skip-until-close-paren-in-slice-stops-at-end:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # setup: (EAX..ECX) = "*(abc"  # unbalanced dquote
    b8/copy-to-EAX  "*(abc"/imm32
    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
    05/add-to-EAX  4/imm32
    # EAX = skip-until-close-paren-in-slice(EAX, ECX)
    # . . push args
    51/push-ECX
    50/push-EAX
    # . . call
    e8/call  skip-until-close-paren-in-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(ECX-EAX, 0, msg)  # skipped to end of slice
    # . . push args
    68/push  "F - test-skip-until-close-paren-in-slice-stops-at-end"/imm32
    68/push  0/imm32
    # . . push ECX-EAX
    29/subtract                     3/mod/direct    1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract EAX from ECX
    51/push-ECX
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

== data
Registers:  # (table string int)
  # a table is a stream
  0x40/imm32/write
  0/imm32/read
  0x40/imm32/length
  # data
  "eax"/imm32  0/imm32
  "ecx"/imm32  1/imm32
  "edx"/imm32  2/imm32
  "ebx"/imm32  3/imm32
  "esp"/imm32  4/imm32
  "ebp"/imm32  5/imm32
  "esi"/imm32  6/imm32
  "edi"/imm32  7/imm32

# . . vim:nowrap:textwidth=0