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| author | Kartik Agaram <vc@akkartik.com> | 2019-02-14 16:24:20 -0800 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-02-14 16:24:20 -0800 |
| commit | 1639687ba098aa81b0584f7dd609cb9690dc5a04 (patch) | |
| tree | 1a5ee40c30bf906c6ba5e55b8c5138a467022105 /subx/072slice.subx | |
| parent | 1ab48a69ccfa4ddaa2e1fa803ea6fe568b890abc (diff) | |
| download | mu-1639687ba098aa81b0584f7dd609cb9690dc5a04.tar.gz | |
4961
Diffstat (limited to 'subx/072slice.subx')
| -rw-r--r-- | subx/072slice.subx | 40 |
1 files changed, 29 insertions, 11 deletions
diff --git a/subx/072slice.subx b/subx/072slice.subx index fa244219..20a39aa4 100644 --- a/subx/072slice.subx +++ b/subx/072slice.subx @@ -21,7 +21,7 @@ slice-empty?: # s : (address slice) -> EAX : boolean 51/push-ECX # ECX = s 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 1/r32/ECX 8/disp8 . # copy *(EBP+8) to ECX - # if s->start == s->end return true + # if (s->start == s->end) return true # . EAX = s->start 8b/copy 0/mod/indirect 1/rm32/ECX . . . 0/r32/EAX . . # copy *ECX to EAX # . compare EAX with s->end @@ -96,6 +96,24 @@ test-slice-empty-false: c3/return slice-equal?: # s : (address slice), p : (address string) -> EAX : boolean + # pseudocode: + # currs = s->start + # maxs = s->end + # if (maxs - currs != p->length) return false + # currp = p->data + # while (currs < maxs) + # if (*currs != *currp) return false + # ++currs + # ++currp + # return true + # + # registers: + # EAX : *currs + # ECX : *currp + # EDX : currs + # EBX : currp + # ESI : maxs + # # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP @@ -106,37 +124,37 @@ slice-equal?: # s : (address slice), p : (address string) -> EAX : boolean 56/push-ESI # ESI = s 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 6/r32/ESI 8/disp8 . # copy *(EBP+8) to ESI - # curr/EDX = s->start + # currs/EDX = s->start 8b/copy 0/mod/indirect 6/rm32/ESI . . . 2/r32/EDX . . # copy *ESI to EDX - # max/ESI = s->end + # maxs/ESI = s->end 8b/copy 1/mod/*+disp8 6/rm32/ESI . . . 6/r32/ESI 4/disp8 . # copy *(ESI+4) to ESI # EBX = p 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 3/r32/EBX 0xc/disp8 . # copy *(EBP+12) to EBX - # EAX = s->end - s->start + # EAX = maxs - currs 89/copy 3/mod/direct 0/rm32/EAX . . . 6/r32/ESI . . # copy ESI to EAX 29/subtract 3/mod/direct 0/rm32/EAX . . . 2/r32/EDX . . # subtract EDX from EAX - # if (EAX != p->length) return false; + # if (EAX != p->length) return false 39/compare 0/mod/indirect 3/rm32/EBX . . . 0/r32/EAX . . # compare *EBX and EAX 75/jump-if-not-equal $slice-equal?:false/disp8 - # skip p->length + # currp/EBX = p->data 81 0/subop/add 3/mod/direct 3/rm32/EBX . . . . . 4/imm32 # add to EBX # EAX = ECX = 0 31/xor 3/mod/direct 0/rm32/EAX . . . 0/r32/EAX . . # clear EAX 31/xor 3/mod/direct 1/rm32/ECX . . . 1/r32/ECX . . # clear ECX $slice-equal?:loop: - # if (curr >= max) return true + # if (currs >= maxs) return true 39/compare 3/mod/direct 2/rm32/EDX . . . 6/r32/ESI . . # compare EDX and ESI 7d/jump-if-greater-or-equal $slice-equal?:true/disp8 - # AL = *p + # AL = *currp 8a/copy-byte 0/mod/indirect 3/rm32/EBX . . . 0/r32/AL . . # copy byte at *EBX to AL - # CL = *curr + # CL = *currs 8a/copy-byte 0/mod/indirect 2/rm32/EDX . . . 1/r32/CL . . # copy byte at *EDX 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-not-equal $slice-equal?:false/disp8 - # ++p + # ++currp 43/increment-EBX - # ++curr + # ++currs 42/increment-EDX eb/jump $slice-equal?:loop/disp8 $slice-equal?:false: |