# some primitives for checking stream contents == 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 # compare all the data in a stream (ignoring the read pointer) stream-data-equal?: # f: (addr stream byte), s: (addr array byte) -> result/eax: boolean # . prologue 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 56/push-esi 57/push-edi # esi = f 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 8/disp8 . # copy *(ebp+8) to esi # eax = f->write 8b/copy 0/mod/indirect 6/rm32/esi . . . 0/r32/eax . . # copy *esi to eax # var maxf/edx: (addr byte) = &f->data[f->write] 8d/copy-address 1/mod/*+disp8 4/rm32/sib 6/base/esi 0/index/eax . 2/r32/edx 0xc/disp8 . # copy esi+eax+12 to edx # var currf/esi: (addr byte) = f->data 81 0/subop/add 3/mod/direct 6/rm32/esi . . . . . 0xc/imm32 # add to esi # edi = s 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 7/r32/edi 0xc/disp8 . # copy *(ebp+12) to edi $stream-data-equal?:compare-sizes: # if (f->write != s->size) return false 39/compare 0/mod/indirect 7/rm32/edi . . . 0/r32/eax . . # compare *edi and eax 75/jump-if-!= $stream-data-equal?:false/disp8 # var currs/edi: (addr byte) = s->data 81 0/subop/add 3/mod/direct 7/rm32/edi . . . . . 4/imm32 # add to edi # var eax: byte = 0 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax # var ecx: byte = 0 31/xor 3/mod/direct 1/rm32/ecx . . . 1/r32/ecx . . # clear ecx $stream-data-equal?:loop: # if (currf >= maxf) return true 39/compare 3/mod/direct 6/rm32/esi . . . 2/r32/edx . . # compare esi with edx 73/jump-if-addr>= $stream-data-equal?:true/disp8 # AL = *currs 8a/copy-byte 0/mod/indirect 6/rm32/esi . . . 0/r32/AL . . # copy byte at *esi to AL # CL = *curr 8a/copy-byte 0/mod/indirect 7/rm32/edi . . . 1/r32/CL . . # copy byte at *edi to CL # if (eax != ecx) return false 39/compare 3/mod/direct 0/rm32/eax . . . 1/r32/ecx . . # compare eax and ecx 75/jump-if-!= $stream-data-equal?:false/disp8 # ++f 46/increment-esi # ++curr 47/increment-edi eb/jump $stream-data-equal?:loop/disp8 $stream-data-equal?:false: b8/copy-to-eax 0/imm32 eb/jump $stream-data-equal?:end/disp8 $stream-data-equal?:true: b8/copy-to-eax 1/imm32 $stream-data-equal?:end: # . restore registers 5f/pop-to-edi 5e/pop-to-esi 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-stream-data-equal: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call write/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = stream-data-equal?(_test-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call stream-data-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 1, msg) # . . push args 68/push "F - test-stream-data-equal"/imm32 68/push 1/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-stream-data-equal-2: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call write/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = stream-data-equal?(_test-stream, "Abd") # . . push args 68/push "Abd"/imm32 68/push _test-stream/imm32 # . . call e8/call stream-data-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-stream-data-equal-2"/imm32 68/push 0/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-stream-data-equal-size-check: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call write/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = stream-data-equal?(_test-stream, "Abcd") # . . push args 68/push "Abcd"/imm32 68/push _test-stream/imm32 # . . call e8/call stream-data-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-stream-data-equal-size-check"/imm32 68/push 0/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return # helper for tests check-stream-equal: # f: (addr stream byte), s: (addr array byte), msg: (addr array byte) # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # . save registers 50/push-eax # eax = stream-data-equal?(f, s) # . . 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 stream-data-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 1, msg) # . . push args ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16) 68/push 1/imm32 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-stream-equal:end: # . restore registers 58/pop-to-eax # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return # scan the next line until newline starting from f->read and compare it with # 's' (ignoring the trailing newline) # on success, set f->read to after the next newline # on failure, leave f->read unmodified # this function is usually used only in tests, so we repeatedly write f->read next-stream-line-equal?: # f: (addr stream byte), s: (addr array byte) -> result/eax: boolean # pseudocode: # currf = f->read # bound: f->write # currs = 0 # bound: s->size # while true # if currf >= f->write # return currs >= s->size # if f[currf] == '\n' # ++currf # return currs >= s->size # if (currs >= s->size) return false # the current line of f still has data to match # if (f[currf] != s[currs]) return false # ++currf # ++currs # # collapsing the two branches that can return true: # currf = f->read # bound: f->write # currs = 0 # bound: s->size # while true # if (currf >= f->write) break # if (f[currf] == '\n') break # if (currs >= s->size) return false # the current line of f still has data to match # if (f[currf] != s[currs]) return false # ++currf # ++currs # ++currf # skip '\n' # return currs >= s->size # Here the final `++currf` is sometimes unnecessary (if we're already at the end of the stream) # # registers: # f: esi # s: edi # currf: ecx # currs: edx # f[currf]: eax # s[currs]: ebx # # . prologue 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 56/push-esi 57/push-edi # esi = f 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 8/disp8 . # copy *(ebp+8) to esi # var currf/ecx: int = f->read 8b/copy 1/mod/*+disp8 6/rm32/esi . . . 1/r32/ecx 4/disp8 . # copy *(esi+4) to ecx # edi = s 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 7/r32/edi 0xc/disp8 . # copy *(ebp+12) to edi # var currs/edx: int = 0 31/xor 3/mod/direct 2/rm32/edx . . . 2/r32/edx . . # clear edx # var c1/eax: byte = 0 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax # var c2/ebx: byte = 0 31/xor 3/mod/direct 3/rm32/ebx . . . 3/r32/ebx . . # clear ebx $next-stream-line-equal?:loop: # if (currf >= f->write) break 3b/compare 0/mod/indirect 6/rm32/esi . . . 1/r32/ecx . . # compare ecx with *esi 7d/jump-if->= $next-stream-line-equal?:break/disp8 # c1 = f->data[f->read] 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 # if (c1 == '\n') break 3d/compare-eax-and 0xa/imm32/newline 74/jump-if-= $next-stream-line-equal?:break/disp8 # if (currs >= s->size) return false 3b/compare 0/mod/indirect 7/rm32/edi . . . 2/r32/edx . . # compare edx with *edi 7d/jump-if->= $next-stream-line-equal?:false/disp8 # c2 = s->data[currs] 8a/copy-byte 1/mod/*+disp8 4/rm32/sib 7/base/edi 2/index/edx . 3/r32/BL 4/disp8 . # copy byte at *(edi+edx+4) to BL # if (c1 != c2) return false 39/compare 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # compare eax and ebx 75/jump-if-!= $next-stream-line-equal?:false/disp8 # ++currf 41/increment-ecx # ++currs 42/increment-edx eb/jump $next-stream-line-equal?:loop/disp8 $next-stream-line-equal?:break: # ++currf 41/increment-ecx # if (currs >= s->size) return true 3b/compare 0/mod/indirect 7/rm32/edi . . . 2/r32/edx . . # compare edx with *edi 7c/jump-if-< $next-stream-line-equal?:false/disp8 $next-stream-line-equal?:true: b8/copy-to-eax 1/imm32 # persist f->read on success 89/copy 1/mod/*+disp8 6/rm32/esi . . . 1/r32/ecx 4/disp8 . # copy ecx to *(esi+4) eb/jump $next-stream-line-equal?:end/disp8 $next-stream-line-equal?:false: b8/copy-to-eax 0/imm32 $next-stream-line-equal?:end: # . restore registers 5f/pop-to-edi 5e/pop-to-esi 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-next-stream-line-equal-stops-at-newline: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc\ndef") # . . push args 68/push "Abc\ndef"/imm32 68/push _test-stream/imm32 # . . call e8/call write/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = next-stream-line-equal?(_test-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 1, msg) # . . push args 68/push "F - test-next-stream-line-equal-stops-at-newline"/imm32 68/push 1/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-next-stream-line-equal-stops-at-newline-2: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc\ndef") # . . push args 68/push "Abc\ndef"/imm32 68/push _test-stream/imm32 # . . call e8/call write/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = next-stream-line-equal?(_test-stream, "def") # . . push args 68/push "def"/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-next-stream-line-equal-stops-at-newline-2"/imm32 68/push 0/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-next-stream-line-equal-skips-newline: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc\ndef\n") # . . push args 68/push "Abc\ndef\n"/imm32 68/push _test-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-stream-line-equal?(_test-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = next-stream-line-equal?(_test-stream, "def") # . . push args 68/push "def"/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 1, msg) # . . push args 68/push "F - test-next-stream-line-equal-skips-newline"/imm32 68/push 1/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-next-stream-line-equal-handles-final-line: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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-stream, "Abc\ndef") # . . push args 68/push "Abc\ndef"/imm32 68/push _test-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-stream-line-equal?(_test-stream, "Abc") # . . push args 68/push "Abc"/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # eax = next-stream-line-equal?(_test-stream, "def") # . . push args 68/push "def"/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 1, msg) # . . push args 68/push "F - test-next-stream-line-equal-skips-newline"/imm32 68/push 1/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-next-stream-line-equal-always-fails-after-Eof: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(_test-stream) # . . push args 68/push _test-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 nothing # eax = next-stream-line-equal?(_test-stream, "") # . . push args 68/push ""/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-next-stream-line-equal-always-fails-after-Eof"/imm32 68/push 1/imm32 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 # eax = next-stream-line-equal?(_test-stream, "") # . . push args 68/push ""/imm32 68/push _test-stream/imm32 # . . call e8/call next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-next-stream-line-equal-always-fails-after-Eof/2"/imm32 68/push 1/imm32 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return # helper for later tests check-next-stream-line-equal: # f: (addr stream byte), s: (addr array byte), msg: (addr array byte) # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # . save registers 50/push-eax # eax = next-stream-line-equal?(f, s) # . . 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 next-stream-line-equal?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # check-ints-equal(eax, 1, msg) # . . push args ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16) 68/push 1/imm32 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 # . restore registers 58/pop-to-eax # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return # . . vim:nowrap:textwidth=0