5050 - compile ModR/M operands

1 files changed, 807 insertions, 1 deletions

diff --git a/subx/apps/pack.subx b/subx/apps/pack.subx
index 8aa09bd9..a856cd4b 100644
--- a/subx/apps/pack.subx
+++ b/subx/apps/pack.subx
@@ -22,7 +22,7 @@
 Entry:  # run tests if necessary, convert stdin if not
 
     # for debugging: run a single test
-#?     e8/call test-convert-code-and-data-segments/disp32
+#?     e8/call test-convert-instruction-emits-modrm-byte/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
 
@@ -2308,8 +2308,302 @@ emit-modrm:  # line : (address stream byte), out : (address buffered-file) -> <v
     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
+    56/push-ESI
+    57/push-EDI
+    # var word-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
+    # var has-modrm?/EDX = false
+    31/xor                          3/mod/direct    2/rm32/EDX    .           .             .           2/r32/EDX   .               .                 # clear EDX
+    # var mod/EBX = 0
+    31/xor                          3/mod/direct    3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # clear EBX
+    # var rm32/ESI = 0
+    31/xor                          3/mod/direct    6/rm32/ESI    .           .             .           6/r32/ESI   .               .                 # clear ESI
+    # var r32/EDI = 0
+    31/xor                          3/mod/direct    7/rm32/EDI    .           .             .           7/r32/EDI   .               .                 # clear EDI
+    # rewind-stream(line)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  rewind-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+$emit-modrm:loop:
+#?     # dump line {{{
+#?     # . write(2/stderr, "LL: ")
+#?     # . . push args
+#?     68/push  "LL: "/imm32
+#?     68/push  2/imm32/stderr
+#?     # . . call
+#?     e8/call  write/disp32
+#?     # . . discard args
+#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+#?     # . write-stream(2/stderr, line)
+#?     # . . push args
+#?     ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+#?     68/push  2/imm32/stderr
+#?     # . . call
+#?     e8/call  write-stream/disp32
+#?     # . . discard args
+#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+#?     # . write(2/stderr, "$")
+#?     # . . 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(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/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
+#?     # }}}
+    # next-word(line, word-slice)
+    # . . push args
+    51/push-ECX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  next-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+#?     # dump word-slice {{{
+#?     # . write(2/stderr, "AA: ")
+#?     # . . push args
+#?     68/push  "AA: "/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)
+#?     # . . 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
+#?     # . write-slice(Stderr, word-slice)
+#?     # . . push args
+#?     51/push-ECX
+#?     68/push  Stderr/imm32
+#?     # . . call
+#?     e8/call  write-slice/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, "$")
+#?     # . . push args
+#?     68/push  "$"/imm32
+#?     68/push  2/imm32/stderr
+#?     # . . call
+#?     e8/call  write/disp32
+#?     # . . discard args
+#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+#?     # . write(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/imm32
+#?     68/push  2/imm32/stderr
+#?     # . . call
+#?     e8/call  write/disp32
+#?     # . . discard args
+#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+#?     # }}}
+$emit-modrm:check0:
+    # if (slice-empty?(word-slice)) break
+    # . EAX = slice-empty?(word-slice)
+    # . . push args
+    51/push-ECX
+    # . . 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) pass through
+    3d/compare-EAX-and  0/imm32
+    0f 85/jump-if-not-equal  $emit-modrm:break/disp32
+$emit-modrm:check1:
+    # if (slice-starts-with?(word-slice, "#")) break
+    # . spill EDX
+    52/push-EDX
+    # . start/EDX = word-slice->start
+    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # copy *ECX to EDX
+    # . c/EAX = *start
+    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
+    8a/copy-byte                    0/mod/indirect  2/rm32/EDX    .           .             .           0/r32/AL    .               .                 # copy byte at *EDX to AL
+    # . restore EDX
+    5a/pop-to-EDX
+    # . if (EAX == '#') pass through
+    3d/compare-EAX-and  0x23/imm32/hash
+    0f 84/jump-if-equal  $emit-modrm:break/disp32
+$emit-modrm:check-for-mod:
+    # if (has-metadata?(word-slice, "mod"))
+    # . EAX = has-metadata?(ECX, "mod")
+    # . . push args
+    68/push  "mod"/imm32
+    51/push-ECX
+    # . . call
+    e8/call  has-metadata?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # . if (EAX == 0) goto next check
+    81          7/subop/compare     3/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm32           # compare EAX
+    74/jump-if-equal  $emit-modrm:check-for-rm32/disp8
+$emit-modrm:mod:
+    # mod = parse-hex-int(next-token-from-slice(word-slice->start, word-slice->end, '/'))
+    # . EAX = parse-datum-of-word(word-slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  parse-datum-of-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # . mod = EAX
+    89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
+    # has-modrm? = true
+    ba/copy-to-EDX  1/imm32/true
+    # continue
+    e9/jump  $emit-modrm:loop/disp32
+$emit-modrm:check-for-rm32:
+    # if (has-metadata?(word-slice, "rm32"))
+    # . EAX = has-metadata?(ECX, "rm32")
+    # . . push args
+    68/push  "rm32"/imm32
+    51/push-ECX
+    # . . call
+    e8/call  has-metadata?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # . if (EAX == 0) goto next check
+    81          7/subop/compare     3/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm32           # compare EAX
+    74/jump-if-equal  $emit-modrm:check-for-r32/disp8
+$emit-modrm:rm32:
+    # rm32 = parse-hex-int(next-token-from-slice(word-slice->start, word-slice->end, '/'))
+    # . EAX = parse-datum-of-word(word-slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  parse-datum-of-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # . rm32 = EAX
+    89/copy                         3/mod/direct    6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy EAX to ESI
+    # has-modrm? = true
+    ba/copy-to-EDX  1/imm32/true
+    # continue
+    e9/jump  $emit-modrm:loop/disp32
+$emit-modrm:check-for-r32:
+    # if (has-metadata?(word-slice, "r32"))
+    # . EAX = has-metadata?(ECX, "r32")
+    # . . push args
+    68/push  "r32"/imm32
+    51/push-ECX
+    # . . call
+    e8/call  has-metadata?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # . if (EAX == 0) goto next check
+    81          7/subop/compare     3/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm32           # compare EAX
+    74/jump-if-equal  $emit-modrm:check-for-subop/disp8
+$emit-modrm:r32:
+    # r32 = parse-hex-int(next-token-from-slice(word-slice->start, word-slice->end, '/'))
+    # . EAX = parse-datum-of-word(word-slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  parse-datum-of-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # . r32 = EAX
+    89/copy                         3/mod/direct    7/rm32/EDI    .           .             .           0/r32/EAX   .               .                 # copy EAX to EDI
+    # has-modrm? = true
+    ba/copy-to-EDX  1/imm32/true
+    # continue
+    e9/jump  $emit-modrm:loop/disp32
+$emit-modrm:check-for-subop:
+    # if (has-metadata?(word-slice, "subop"))
+    # . EAX = has-metadata?(ECX, "subop")
+    # . . push args
+    68/push  "subop"/imm32
+    51/push-ECX
+    # . . call
+    e8/call  has-metadata?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # . if (EAX == 0) loop
+    81          7/subop/compare     3/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm32           # compare EAX
+    0f 84/jump-if-equal  $emit-modrm:loop/disp32
+$emit-modrm:subop:
+    # r32 = parse-hex-int(next-token-from-slice(word-slice->start, word-slice->end, '/'))
+    # . EAX = parse-datum-of-word(word-slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  parse-datum-of-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # . r32 = EAX
+    89/copy                         3/mod/direct    7/rm32/EDI    .           .             .           0/r32/EAX   .               .                 # copy EAX to EDI
+    # has-modrm? = true
+    ba/copy-to-EDX  1/imm32/true
+    # continue
+    e9/jump  $emit-modrm:loop/disp32
+$emit-modrm:break:
+    # if (!has-modrm?) return
+    81          7/subop/compare     3/mod/direct    2/rm32/EDX    .           .             .           .           .               0/imm32           # compare EDX
+    74/jump-if-equal  $emit-modrm:end/disp8
+$emit-modrm:calculate:
+$emit-modrm:add-mod:
+    # modrm/EBX = mod & 0b11
+    81          4/subop/and         3/mod/direct    3/rm32/EBX    .           .             .           .           .               3/imm32/0b11      # bitwise and of EBX
+    # modrm <<= 2
+    c1/shift    4/subop/left        3/mod/direct    3/rm32/EBX    .           .             .           .           .               2/imm8            # shift EBX left by 2 bits
+$emit-modrm:add-r32:
+    # modrm |= r32 & 0b111
+    81          4/subop/and         3/mod/direct    7/rm32/EDI    .           .             .           .           .               7/imm32/0b111     # bitwise and of EDI
+    09/or                           3/mod/direct    3/rm32/EBX    .           .             .           7/r32/EDI   .               .                 # EBX = bitwise OR with EDI
+    # modrm <<= 3
+    c1/shift    4/subop/left        3/mod/direct    3/rm32/EBX    .           .             .           .           .               3/imm8            # shift EBX left by 3 bits
+$emit-modrm:add-rm32:
+    # modrm |= rm32 & 0b111
+    81          4/subop/and         3/mod/direct    6/rm32/ESI    .           .             .           .           .               7/imm32/0b111     # bitwise and of ESI
+    09/or                           3/mod/direct    3/rm32/EBX    .           .             .           6/r32/ESI   .               .                 # EBX = bitwise OR with ESI
+$emit-modrm:emit:
+    # emit-hex(out, modrm, 1)
+    # . . push args
+    68/push  1/imm32
+    53/push-EBX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
+    # . . call
+    e8/call  emit-hex/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
 $emit-modrm:end:
+    # . restore locals
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
     # . restore registers
+    5f/pop-to-EDI
+    5e/pop-to-ESI
+    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
@@ -3979,6 +4273,516 @@ test-convert-instruction-handles-unused-second-opcodes-2:
     5d/pop-to-EBP
     c3/return
 
+test-convert-instruction-emits-modrm-byte:
+    # pack mod, rm32 and r32 operands into ModR/M byte
+    # . 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-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, "8b/copy 0/mod 0/rm32 1/r32")
+    # . . push args
+    68/push  "8b/copy 0/mod 0/rm32 1/r32"/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-instruction(_test-input-stream, _test-output-buffered-file)
+    # . . push args
+    68/push  _test-output-buffered-file/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  convert-instruction/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check output
+    # . 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, "$")
+#?     # . . push args
+#?     68/push  "$"/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(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/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, "8b 08  # 8b/copy 0/mod 0/rm32 1/r32", msg)
+    # . . push args
+    68/push  "F - test-convert-instruction-emits-modrm-byte"/imm32
+    68/push  "8b 08  # 8b/copy 0/mod 0/rm32 1/r32"/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-instruction-emits-modrm-byte-from-subop:
+    # pack mod, rm32 and subop operands into ModR/M byte
+    # . 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-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, "ff 6/subop/push 0/mod 0/rm32")
+    # . . push args
+    68/push  "ff 6/subop/push 0/mod 0/rm32"/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-instruction(_test-input-stream, _test-output-buffered-file)
+    # . . push args
+    68/push  _test-output-buffered-file/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  convert-instruction/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check output
+    # . 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, "$")
+#?     # . . push args
+#?     68/push  "$"/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(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/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, "ff 30  # ff 6/subop/push 0/mod 0/rm32", msg)
+    # . . push args
+    68/push  "F - test-convert-instruction-emits-modrm-byte-from-subop"/imm32
+    68/push  "ff 30  # ff 6/subop/push 0/mod 0/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-convert-instruction-emits-modrm-byte-with-missing-mod:
+    # pack rm32 and r32 operands into ModR/M byte
+    # . 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-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, "8b/copy 0/rm32 1/r32")
+    # . . push args
+    68/push  "8b/copy 0/rm32 1/r32"/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-instruction(_test-input-stream, _test-output-buffered-file)
+    # . . push args
+    68/push  _test-output-buffered-file/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  convert-instruction/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check output
+    # . 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, "$")
+#?     # . . push args
+#?     68/push  "$"/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(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/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, "8b 08  # 8b/copy 0/rm32 1/r32", msg)
+    # . . push args
+    68/push  "F - test-convert-instruction-emits-modrm-byte-with-missing-mod"/imm32
+    68/push  "8b 08  # 8b/copy 0/rm32 1/r32"/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-instruction-emits-modrm-byte-with-missing-rm32:
+    # pack mod and r32 operands into ModR/M byte
+    # . 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-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, "8b/copy 0/mod 1/r32")
+    # . . push args
+    68/push  "8b/copy 0/mod 1/r32"/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-instruction(_test-input-stream, _test-output-buffered-file)
+    # . . push args
+    68/push  _test-output-buffered-file/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  convert-instruction/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check output
+    # . 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, "$")
+#?     # . . push args
+#?     68/push  "$"/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(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/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, "8b 08  # 8b/copy 0/mod 1/r32", msg)
+    # . . push args
+    68/push  "F - test-convert-instruction-emits-modrm-byte-with-missing-rm32"/imm32
+    68/push  "8b 08  # 8b/copy 0/mod 1/r32"/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-instruction-emits-modrm-byte-with-missing-r32:
+    # pack mod and rm32 operands into ModR/M byte
+    # . 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-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, "8b/copy 0/mod 0/rm32")
+    # . . push args
+    68/push  "8b/copy 0/mod 0/rm32"/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-instruction(_test-input-stream, _test-output-buffered-file)
+    # . . push args
+    68/push  _test-output-buffered-file/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  convert-instruction/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check output
+    # . 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, "$")
+#?     # . . push args
+#?     68/push  "$"/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(2/stderr, "\n")
+#?     # . . push args
+#?     68/push  Newline/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, "8b 00  # 8b/copy 0/mod 0/rm32", msg)
+    # . . push args
+    68/push  "F - test-convert-instruction-emits-modrm-byte-with-missing-r32"/imm32
+    68/push  "8b 00  # 8b/copy 0/mod 0/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-convert-instruction-handles-disp32-operand:
     # expand /disp32 operand into 4 bytes
     # . prolog
@@ -6055,6 +6859,8 @@ parse-datum-of-word:  # word : (address slice) -> value/EAX
     # . . discard args
     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
 $parse-datum-of-word: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