| 0,0 → 1,213 |
|---|
| ;***************************************************************************** |
| ;* |
| ;* Open Watcom Project |
| ;* |
| ;* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved. |
| ;* |
| ;* ======================================================================== |
| ;* |
| ;* This file contains Original Code and/or Modifications of Original |
| ;* Code as defined in and that are subject to the Sybase Open Watcom |
| ;* Public License version 1.0 (the 'License'). You may not use this file |
| ;* except in compliance with the License. BY USING THIS FILE YOU AGREE TO |
| ;* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is |
| ;* provided with the Original Code and Modifications, and is also |
| ;* available at www.sybase.com/developer/opensource. |
| ;* |
| ;* The Original Code and all software distributed under the License are |
| ;* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| ;* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM |
| ;* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF |
| ;* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR |
| ;* NON-INFRINGEMENT. Please see the License for the specific language |
| ;* governing rights and limitations under the License. |
| ;* |
| ;* ======================================================================== |
| ;* |
| ;* Description: Intel 386 implementation strcmp(). |
| ;* |
| ;***************************************************************************** |
| |
| |
| include mdef.inc |
| include struct.inc |
| |
| ifdef _PROFILE |
| include p5prof.inc |
| endif |
| |
| modstart _strcmp,para |
| |
| cmp4 macro off |
| mov ebx,off[eax] ; get dword from op1 |
| mov ecx,off[edx] ; get dword from op2 |
| cmp ecx,ebx ; compare them |
| jne unequal ; quit if not equal |
| ife off-12 |
| add eax,off+4 ; point to next group of dwords |
| add edx,off+4 ; ... |
| endif |
| not ecx ; ... |
| add ebx,0FEFEFEFFh ; determine if '\0' is one of bytes |
| and ebx,ecx ; ... |
| and ebx,80808080h ; ebx will be non-zero if '\0' found |
| endm |
| |
| defpe strcmp |
| xdefp "C",strcmp |
| ifdef _PROFILE |
| P5Prolog |
| endif |
| ifdef __STACK__ |
| mov eax,4[esp] ; get p1 |
| mov edx,8[esp] ; get p2 |
| endif |
| cmp eax,edx ; pointers equal ? |
| je equalnorst ; yes, return 0 |
| ifndef __STACK__ |
| push ecx ; save register |
| endif |
| test al,3 ; p1 aligned ? |
| jne realign ; no, go and realign |
| test dl,3 ; p2 aligned ? |
| jne slowcpy ; no, do the slow copy (impossible to align both) |
| |
| fastcpy: |
| push ebx ; save register |
| |
| align 4 |
| _loop ; - loop |
| cmp4 0 ; - - compare first dword |
| _quif ne ; - - quit if end of string |
| cmp4 4 ; - - compare second dword |
| _quif ne ; - - quit if end of string |
| cmp4 8 ; - - compare third dword |
| _quif ne ; - - quit if end of string |
| cmp4 12 ; - - compare fourth dword |
| _until ne ; - until end of string |
| equalrst: ; strings equal, restore registers |
| pop ebx ; restore register |
| ifndef __STACK__ |
| pop ecx ; ... |
| endif |
| equalnorst: ; strings equal, skip register restore |
| sub eax,eax ; indicate strings equal |
| ifdef _PROFILE |
| P5Epilog |
| endif |
| ret ; return |
| |
| unequal: ; dword was not equal |
| _guess ; guess strings are equal |
| cmp bl,cl ; - check low bytes |
| _quif ne ; - quit if not equal |
| cmp bl,0 ; - stop if end of string |
| je equalrst ; - ... |
| cmp bh,ch ; - check next bytes |
| _quif ne ; - quit if not equal |
| cmp bh,0 ; - stop if end of string |
| je equalrst ; - ... |
| shr ebx,16 ; - shift top 2 bytes to bottom |
| shr ecx,16 ; - ... |
| cmp bl,cl ; - check third byte |
| _quif ne ; - quit if not equal |
| cmp bl,0 ; - stop if end of string |
| je equalrst ; - ... |
| cmp bh,ch ; - check high order byte |
| ;; we know at this point that bh != ch, just have to do the compare |
| ;; _quif ne ; - quit if not equal |
| ;; cmp bh,0 ; - stop if end of string |
| ;; je equalrst ; - ... |
| _endguess ; endguess |
| sbb eax,eax ; eax = 0 if op1>op2, -1 if op1<op2 |
| or al,1 ; eax = 1 if op1>op2, -1 if op1<op2 |
| pop ebx ; restore registers |
| ifndef __STACK__ |
| pop ecx ; ... |
| endif |
| ifdef _PROFILE |
| P5Epilog |
| endif |
| ret ; return |
| |
| align 4 |
| realign: |
| _loop ; - loop |
| mov cl,[eax] ; get byte from p1 |
| inc eax ; point to next byte |
| mov ch,[edx] ; get byte from p2 |
| inc edx ; point to next byte |
| cmp cl,ch ; bytes equal? |
| jne unequal2 ; unequal, quit |
| or cl,cl ; end of string ? |
| je equal2 ; yes, quit |
| test al,3 ; check alignment |
| _until e ; until aligned |
| test dl,3 ; p2 aligned ? |
| je fastcpy ; yes |
| |
| align 4 |
| slowcpy: |
| _loop |
| mov ecx,[eax] ; get aligned 4 bytes |
| cmp cl,[edx] ; check 1st byte |
| jne unequal2 ; bytes not equal |
| or cl,cl ; end of string? |
| je equal2 ; yes, quit |
| cmp ch,[edx+1] ; check 2nd byte |
| jne unequal2 ; bytes not equal |
| or ch,ch ; end of string? |
| je equal2 ; yes, quit |
| shr ecx,16 ; move next pair of bytes to be tested |
| cmp cl,[edx+2] ; check 3rd byte |
| jne unequal2 ; bytes not equal |
| or cl,cl ; end of string? |
| je equal2 ; yes, quit |
| cmp ch,[edx+3] ; check 4th byte |
| jne unequal2 ; bytes not equal |
| or ch,ch ; end of string? |
| je equal2 ; yes, quit |
| mov ecx,[eax+4] ; get next aligned 4 bytes |
| cmp cl,[edx+4] ; check 5th byte |
| jne unequal2 ; bytes not equal |
| or cl,cl ; end of string? |
| je equal2 ; yes, quit |
| cmp ch,[edx+5] ; check 6th byte |
| jne unequal2 ; bytes not equal |
| or ch,ch ; end of string? |
| je equal2 ; yes, quit |
| shr ecx,16 ; move next pair of bytes to be tested |
| cmp cl,[edx+6] ; check 7th byte |
| jne unequal2 ; bytes not equal |
| or cl,cl ; end of string? |
| je equal2 ; yes, quit |
| cmp ch,[edx+7] ; check 8th byte |
| jne unequal2 ; bytes not equal |
| add eax,8 ; next 8 bytes |
| add edx,8 ; next 8 bytes |
| or ch,ch ; end of string? |
| _until e ; until equal |
| equal2: |
| xor eax,eax ; return 0 |
| ifndef __STACK__ |
| pop ecx ; restore registers |
| endif |
| ifdef _PROFILE |
| P5Epilog |
| endif |
| ret ; return |
| |
| unequal2: |
| sbb eax,eax ; eax = 0 if op1>op2, -1 if op1<op2 |
| or al,1 ; eax = 1 if op1>op2, -1 if op1<op2 |
| ifndef __STACK__ |
| pop ecx ; restore registers |
| endif |
| ifdef _PROFILE |
| P5Epilog |
| endif |
| ret ; return |
| endproc strcmp |
| |
| endmod |
| end |