311decimal-int.subx - mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

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[flake8]
max-line-length = 99
ignore = E221,W503

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# Helpers for decimal ints. parse-decimal-int-from-slice: # in: (addr slice) -> out/eax: int # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 51/push-ecx # ecx = in 8b/-> *(ebp+8) 1/r32/ecx # (parse-decimal-int-helper *ecx *(ecx+4)) # => eax $parse-decimal-int-from-slice:end: # . restore registers 59/pop-to-ecx # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return parse-decimal-int: # in: (addr array byte) -> result/eax: int # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 51/push-ecx 52/push-edx # eax = in 8b/-> *(ebp+8) 0/r32/eax # var start/ecx: (addr byte) = &in->data 8d/copy-address *(eax+4) 1/r32/ecx # var end/edx: (addr byte) = &in->data[in->size] 8b/-> *eax 2/r32/edx 8d/copy-address *(eax+edx+4) 2/r32/edx # (parse-decimal-int-helper %ecx %edx) # => eax $parse-decimal-int:end: # . restore registers 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return parse-decimal-int-from-stream: # in: (addr stream byte) -> result/eax: int # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 51/push-ecx 52/push-edx # eax = in 8b/-> *(ebp+8) 0/r32/eax # var start/ecx: (addr byte) = &in->data[in->read] 8b/-> *(eax+4) 1/r32/ecx 8d/copy-address *(eax+ecx+0xc) 1/r32/ecx # var end/edx: (addr byte) = &in->data[in->write] 8b/-> *eax 2/r32/edx 8d/copy-address *(eax+edx+0xc) 2/r32/edx # (parse-decimal-int-helper %ecx %edx) # => eax $parse-decimal-int-from-stream:end: # . restore registers 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return parse-decimal-int-helper: # start: (addr byte), end: (addr byte) -> result/eax: int # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 51/push-ecx 52/push-edx 53/push-ebx 56/push-esi 57/push-edi # var curr/esi: (addr byte) = start 8b/-> *(ebp+8) 6/r32/esi # edi = end 8b/-> *(ebp+0xc) 7/r32/edi # var negate?/edx: boolean = false ba/copy-to-edx 0/imm32/false # if (*curr == '-') ++curr, negate = true { $parse-decimal-int-helper:negative: b8/copy-to-eax 0/imm32 8a/copy-byte *esi 0/r32/AL 3d/compare-eax-and 0x2d/imm32/- 75/jump-if-!= break/disp8 # . ++curr 46/increment-esi # . negate = true ba/copy-to-edx 1/imm32/true } # spill negate? 52/push-edx # var result/eax: int = 0 b8/copy-to-eax 0/imm32 # var digit/ecx: int = 0 b9/copy-to-ecx 0/imm32 # const TEN/ebx: int = 10 bb/copy-to-ebx 0xa/imm32 { $parse-decimal-int-helper:loop: # if (curr >= in->end) break 39/compare %esi 7/r32/edi 73/jump-if-addr>= break/disp8 # digit = from-decimal-char(*curr) 8a/copy-byte *esi 1/r32/CL 81 5/subop/subtract %ecx 0x30/imm32/zero # TODO: error checking # result = result * 10 + digit ba/copy-to-edx 0/imm32 f7 4/subop/multiply-into-edx-eax %ebx # TODO: check edx for overflow 01/add %eax 1/r32/ecx # ++curr 46/increment-esi # eb/jump loop/disp8 } $parse-decimal-int-helper:negate: # if (negate?) result = -result 5a/pop-to-edx { 81 7/subop/compare %edx 0/imm32/false 74/jump-if-= break/disp8 f7 3/subop/negate %eax } $parse-decimal-int-helper:end: # . restore registers 5f/pop-to-edi 5e/pop-to-esi 5b/pop-to-ebx 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-parse-decimal-int-from-slice-single-digit: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 50/push-eax 51/push-ecx # (eax..ecx) = "3" b8/copy-to-eax "3"/imm32 8b/-> *eax 1/r32/ecx 8d/copy-address *(eax+ecx+4) 1/r32/ecx 05/add-to-eax 4/imm32 # var slice/ecx: slice = {eax, ecx} 51/push-ecx 50/push-eax 89/<- %ecx 4/r32/esp # (parse-decimal-int-from-slice %ecx) # => eax (check-ints-equal %eax 3 "F - test-parse-decimal-int-from-slice-single-digit") $test-parse-decimal-int-helper-single-digit:end: # . restore registers 59/pop-to-ecx 58/pop-to-eax # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-parse-decimal-int-from-slice-multi-digit: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 50/push-eax 51/push-ecx # (eax..ecx) = "34" b8/copy-to-eax "34"/imm32 8b/-> *eax 1/r32/ecx 8d/copy-address *(eax+ecx+4) 1/r32/ecx 05/add-to-eax 4/imm32 # var slice/ecx: slice = {eax, ecx} 51/push-ecx 50/push-eax 89/<- %ecx 4/r32/esp # (parse-decimal-int-from-slice %ecx) # => eax (check-ints-equal %eax 0x22 "F - test-parse-decimal-int-from-slice-multi-digit") # 34 in hex $test-parse-decimal-int-helper-multi-digit:end: # . restore registers 59/pop-to-ecx 58/pop-to-eax # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-parse-decimal-int-from-slice-zero: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 50/push-eax 51/push-ecx # (eax..ecx) = "00" b8/copy-to-eax "00"/imm32 8b/-> *eax 1/r32/ecx 8d/copy-address *(eax+ecx+4) 1/r32/ecx 05/add-to-eax 4/imm32 # var slice/ecx: slice = {eax, ecx} 51/push-ecx 50/push-eax 89/<- %ecx 4/r32/esp # (parse-decimal-int-from-slice %ecx) # => eax (check-ints-equal %eax 0 "F - test-parse-decimal-int-from-slice-zero") $test-parse-decimal-int-helper-zero:end: # . restore registers 59/pop-to-ecx 58/pop-to-eax # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-parse-decimal-int-from-slice-negative: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 50/push-eax 51/push-ecx # (eax..ecx) = "-3" b8/copy-to-eax "-3"/imm32 8b/-> *eax 1/r32/ecx 8d/copy-address *(eax+ecx+4) 1/r32/ecx 05/add-to-eax 4/imm32 # var slice/ecx: slice = {eax, ecx} 51/push-ecx 50/push-eax 89/<- %ecx 4/r32/esp # (parse-decimal-int-from-slice %ecx) # => eax (check-ints-equal %eax -3 "F - test-parse-decimal-int-from-slice-negative") $test-parse-decimal-int-helper-negative:end: # . restore registers 59/pop-to-ecx 58/pop-to-eax # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-parse-decimal-int-from-slice-multi-digit-negative: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 50/push-eax 51/push-ecx # (eax..ecx) = "-32" b8/copy-to-eax "-32"/imm32 8b/-> *eax 1/r32/ecx 8d/copy-address *(eax+ecx+4) 1/r32/ecx 05/add-to-eax 4/imm32 # var slice/ecx: slice = {eax, ecx} 51/push-ecx 50/push-eax 89/<- %ecx 4/r32/esp # (parse-decimal-int-from-slice %ecx) # => eax (check-ints-equal %eax -0x20 "F - test-parse-decimal-int-from-slice-multi-digit-negative") # -32 in hex $test-parse-decimal-int-helper-multi-digit-negative:end: # . restore registers 59/pop-to-ecx 58/pop-to-eax # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return decimal-size: # n: int -> result/eax: int # pseudocode: # edi = 0 # eax = n # if eax < 0 # ++edi # for '-' # negate eax # while true # edx = 0 # eax, edx = eax/10, eax%10 # ++edi # if (eax == 0) break # eax = edi # # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # . save registers 51/push-ecx 52/push-edx 57/push-edi # edi = 0 bf/copy-to-edi 0/imm32 # eax = n 8b/-> *(ebp+8) 0/r32/eax # if (n < 0) negate n, increment edi { 3d/compare-eax-with 0/imm32 7d/jump-if->= break/disp8 f7 3/subop/negate %eax 47/increment-edi } # const ten/ecx = 10 b9/copy-to-ecx 0xa/imm32 { ba/copy-to-edx 0/imm32 f7 7/subop/idiv-edx-eax-by %ecx # eax = edx:eax/10; edx = edx:eax%10 47/increment-edi 3d/compare-eax-and 0/imm32 75/jump-if-!= loop/disp8 } $decimal-size:end: 89/<- %eax 7/r32/edi # . restore registers 5f/pop-to-edi 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-decimal-size-of-zero: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # (decimal-size 0) # => eax (check-ints-equal %eax 1 "F - test-decimal-size-of-zero") $test-decimal-size-of-zero:end: # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-decimal-size-single-digit: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # (decimal-size 4) # => eax (check-ints-equal %eax 1 "F - test-decimal-size-single-digit") $test-decimal-size-single-digit:end: # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-decimal-size-multi-digit: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # (decimal-size 0xa) # => eax (check-ints-equal %eax 2 "F - test-decimal-size-multi-digit") $test-decimal-size-multi-digit:end: # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-decimal-size-single-digit-negative: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # (decimal-size -4) # => eax (check-ints-equal %eax 2 "F - test-decimal-size-single-digit-negative") $test-decimal-size-single-digit-negative:end: # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return test-decimal-size-multi-digit-negative: # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # (decimal-size -0xa) # => eax (check-ints-equal %eax 3 "F - test-decimal-size-multi-digit-negative") $test-decimal-size-multi-digit-negative:end: # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp c3/return

<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Mu - 112read-byte.subx</title> <meta name="Generator" content="Vim/8.2"> <meta name="plugin-version" content="vim8.1_v2"> <meta name="syntax" content="none"> <meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy=,use_input_for_pc=fallback"> <meta name="colorscheme" content="minimal-light"> <style>  </style> <script>  </script> </head> <body onload='JumpToLine();'> <a href='https://github.com/akkartik/mu/blob/main/112read-byte.subx'>https://github.com/akkartik/mu/blob/main/112read-byte.subx</a> <pre id='vimCodeElement'> 1 # Read a single byte from a stream. 2 # 3 # We need to do this in machine code because streams need to be opaque types, 4 # and we don't yet support opaque types in Mu. 5 6 == code 7 # instruction effective address register displacement immediate 8 # . op subop mod rm32 base index scale r32 9 # . 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 10 11 # Return next byte value in eax, with top 3 bytes cleared. 12 # Abort on reaching end of stream. 13 read-byte: # s: (addr stream byte) -> result/eax: byte 14 # . prologue 15 55/push-ebp 16 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 17 # . save registers 18 51/push-ecx 19 56/push-esi 20 # esi = s 21 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 8/disp8 . # copy *(ebp+8) to esi 22 # ecx = s->read 23 8b/copy 1/mod/*+disp8 6/rm32/esi . . . 1/r32/ecx 4/disp8 . # copy *(esi+4) to ecx 24 # if (f->read >= f->write) abort 25 3b/compare 0/mod/indirect 6/rm32/esi . . . 1/r32/ecx . . # compare ecx with *esi 26 0f 8d/jump-if->= $read-byte:<a href='317abort.subx.html#L5'>abort</a>/disp32 27 # result = f->data[f->read] 28 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax 29 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 30 # ++f->read 31 ff 0/subop/increment 1/mod/*+disp8 6/rm32/esi . . . . 4/disp8 . # increment *(esi+4) 32 $read-byte:end: 33 # . restore registers 34 5e/pop-to-esi 35 59/pop-to-ecx 36 # . epilogue 37 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 38 5d/pop-to-ebp 39 c3/return 40 41 $read-byte:<a href='317abort.subx.html#L5'>abort</a>: 42 (<a href='317abort.subx.html#L5'>abort</a> "read-byte: empty stream") 43 # never gets here 44 45 # Return next byte value in eax, with top 3 bytes cleared. 46 # Abort on reaching end of stream. 47 peek-byte: # s: (addr stream byte) -> result/eax: byte 48 # . prologue 49 55/push-ebp 50 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 51 # . save registers 52 51/push-ecx 53 56/push-esi 54 # esi = s 55 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 8/disp8 . # copy *(ebp+8) to esi 56 # ecx = s->read 57 8b/copy 1/mod/*+disp8 6/rm32/esi . . . 1/r32/ecx 4/disp8 . # copy *(esi+4) to ecx 58 # if (f->read >= f->write) abort 59 3b/compare 0/mod/indirect 6/rm32/esi . . . 1/r32/ecx . . # compare ecx with *esi 60 0f 8d/jump-if->= $peek-byte:<a href='317abort.subx.html#L5'>abort</a>/disp32 61 # result = f->data[f->read] 62 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax 63 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 64 $peek-byte:end: 65 # . restore registers 66 5e/pop-to-esi 67 59/pop-to-ecx 68 # . epilogue 69 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 70 5d/pop-to-ebp 71 c3/return 72 73 $peek-byte:<a href='317abort.subx.html#L5'>abort</a>: 74 (<a href='317abort.subx.html#L5'>abort</a> "peek-byte: empty stream") 75 # never gets here 76 77 == data 78 79 _test-input-stream: # (stream byte) 80 # current write index 81 0/imm32 82 $_test-input-stream->read: 83 # current read index 84 0/imm32 85 # size 86 0x400/imm32 # 1024 bytes 87 # data (64 lines x 16 bytes/line) 88 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 89 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 91 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 92 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 93 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 94 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 95 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 96 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 97 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 98 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 99 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 100 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 101 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 102 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 103 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 104 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 105 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 106 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 107 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 108 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 109 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 111 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 112 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 113 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 114 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 115 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 116 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 117 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 118 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 119 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 120 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 121 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 122 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 123 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 124 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 125 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 126 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 127 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 128 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 129 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 131 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 132 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 133 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 134 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 135 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 136 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 137 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 138 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 139 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 141 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 142 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 143 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 144 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 145 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 146 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 147 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 148 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 149 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 151 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 152 153 # . . vim:nowrap:textwidth=0 </pre> </body> </html>