~drizzle-trunk/drizzle/development

; Copyright (C) 2000 MySQL AB

; 

; This library is free software; you can redistribute it and/or

; modify it under the terms of the GNU Library General Public

; License as published by the Free Software Foundation; version 2

; of the License.

; 

; This library is distributed in the hope that it will be useful,

; but WITHOUT ANY WARRANTY; without even the implied warranty of

; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

; Library General Public License for more details.

; 

; You should have received a copy of the GNU Library General Public

; License along with this library; if not, write to the Free

; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,

; MA 02111-1307, USA

	TITLE   Optimized cmp of pointer to strings of unsigned chars

ifndef M_I386

	.8087

	DOSSEG

	.MODEL LARGE

	.DATA

compare_length dw	0

	.CODE STRINGS

	PUBLIC	_get_ptr_compare

_get_ptr_compare	PROC

	mov	bx,sp

	mov	cx,ss:[BX+4]

	mov	compare_length,cx

	mov	dx,seg strings:_ptr_cmp

	mov	ax,offset _ptr_cmp_0

	jcxz	@F

	mov	ax,offset _ptr_cmp_1

	dec	cx

	jz	@F

	mov	ax,offset _ptr_cmp

@@:	ret

_get_ptr_compare ENDP

_ptr_cmp_0	PROC

	mov	AX,0			; Emptyt strings are always equal

	ret

_ptr_cmp_0	ENDP

_ptr_cmp_1	PROC

	mov	bx,sp

	mov	dx,si			; Save si and ds

	mov	cx,ds

	lds	si,DWORD PTR ss:[bx+4]	; s1

	lds	si,DWORD PTR ds:[si]

	mov	al,ds:[si]

	xor	ah,ah

	lds	si,DWORD PTR ss:[bx+8]	; s2

	lds	si,DWORD PTR ds:[si]

	mov	bl,ds:[si]

	mov	bh,ah

	sub	ax,bx

	mov	ds,cx			; restore si and ds

	mov	si,dx

	ret

_ptr_cmp_1 ENDP

_ptr_cmp	PROC

	mov	bx,bp			; Save bp

	mov	dx,di			; Save di

	mov	bp,sp

	push	ds

	push	si

	mov	cx,compare_length	; Length of memory-area

	lds	si,DWORD PTR [bp+4]	; s1

	lds	si,DWORD PTR ds:[si]

	les	di,DWORD PTR [bp+8]	; s2

	les	di,DWORD PTR es:[di]

;	cld				; Work uppward

	xor	ax,ax

	repe	cmpsb			; Compare strings

	je	@F			; Strings are equal

	sbb	ax,ax

	cmc

	adc	ax,0

@@:	pop	si

	pop	ds

	mov	di,dx

	mov	bp,bx

	ret

_ptr_cmp ENDP

else

include macros.asm

fix_es  MACRO   fix_cld                 ; Load ES if neaded

  ife ESeqDS

        mov     ax,ds

        mov     es,ax

  endif

  ifnb <fix_cld>

        cld

  endif

        ENDM

	begdata

compare_length dd	0		; Length of strings

	enddata

	begcode get_ptr_compare

	public	_get_ptr_compare

_get_ptr_compare	proc near

	mov	ecx,P-SIZEPTR[esp]

	mov	compare_length,ecx

	mov	eax,offset _TEXT:_ptr_cmp_0

	jecxz	@F

	mov	eax,offset _TEXT:_ptr_cmp_1

	dec	ecx

	jz	@F

	mov	eax,offset _TEXT:_ptr_cmp

@@:	ret

_get_ptr_compare endp

	endcode _get_ptr_compare

	begcode	ptr_cmp_0

_ptr_cmp_0	PROC

	mov	EAX,0			; Emptyt strings are always equal

	ret

_ptr_cmp_0	ENDP

	endcode	ptr_cmp_0

	begcode	ptr_cmp_1

_ptr_cmp_1	proc near

	mov	edx,esi			; Save esi

	mov	esi,P-SIZEPTR[esp]	; *s1

	mov	esi,[esi]

	movzx	eax,[esi]

	mov	esi,P[esp]		; *s2

	mov	esi,[esi]

	movzx	ecx,[esi]

	sub	eax,ecx

	mov	esi,edx			; Restore esi

	ret

_ptr_cmp_1 ENDP

	endcode ptr_cmp_1

	begcode	ptr_cmp

_ptr_cmp	proc near

	fix_es	1

	push	ebp

	mov	ebp,esp

	mov	edx,edi			; Save esi

	push	esi

	mov	esi,P[ebp]		; *s1

	mov	esi,[esi]

	mov	edi,P+SIZEPTR[ebp]	; *s2

	mov	edi,[edi]

	mov	ecx,compare_length	; Length of memory-area

	xor	eax,eax

	repe	cmpsb			; Compare strings

	je	@F			; Strings are equal

	sbb	eax,eax

	cmc

	adc	eax,0

@@:	pop	esi

	mov	edi,edx

	pop	ebp

	ret

_ptr_cmp ENDP

	endcode	ptr_cmp

endif

	END