# 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) -> 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-lengths:
# if (f->write != s->length) 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-length-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-length-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 later 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) -> eax: boolean
# pseudocode:
# currf = f->read # bound: f->write
# currs = 0 # bound: s->length
# while true
# if currf >= f->write
# return currs >= s->length
# if f[currf] == '\n'
# ++currf
# return currs >= s->length
# if (currs >= s->length) 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->length
# while true
# if (currf >= f->write) break
# if (f[currf] == '\n') break
# if (currs >= s->length) 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->length
# 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->length) 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->length) 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:
# . 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