view src/hermes/x86_main.asm @ 1240:3b8a43c428bb

From Bug #36: There are a couple of issues with the selection of Altivec alpha-blitting routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c. 1) There's no check for the presence of Altivec when checking if the Blit32to565PixelAlphaAltivec() routine can be selected. 2) Altivec cannot be used in video memory, and there's no check if the destination surface is a hardware surface. (Alpha-blitting to a hardware surface with GPU support is a bad idea, but somebody's bound to do it anyway.) Patch to fix these attached.
author Ryan C. Gordon <icculus@icculus.org>
date Sun, 08 Jan 2006 21:18:15 +0000
parents 3202d727bb4b
children 393092a3ebf6
line wrap: on
line source

;
; x86 format converters for HERMES
; Some routines Copyright (c) 1998 Christian Nentwich (brn@eleet.mcb.at)
; This source code is licensed under the GNU LGPL
; 
; Please refer to the file COPYING.LIB contained in the distribution for
; licensing conditions		
;
; Most routines are (c) Glenn Fiedler (ptc@gaffer.org), used with permission
; 

BITS 32

GLOBAL _ConvertX86
GLOBAL _x86return
	
GLOBAL _Hermes_X86_CPU

SECTION .text
		
;; _ConvertX86:	 
;; [ESP+8] ConverterInfo*
;; --------------------------------------------------------------------------
;; ConverterInfo (ebp+..)
;;   0:	void *s_pixels
;;   4:	int s_width
;;   8:	int s_height
;;  12:	int s_add
;;  16:	void *d_pixels
;;  20:	int d_width
;;  24:	int d_height
;;  28:	int d_add
;;  32:	void (*converter_function)() 
;;  36: int32 *lookup
	
_ConvertX86:
	push ebp
	mov ebp,esp

; Save the registers used by the blitters, necessary for optimized code
	pusha

	mov eax,[ebp+8]

        cmp dword [eax+4],BYTE 0
	je endconvert
	
	mov ebp,eax
	
	mov esi,[ebp+0]
	mov edi,[ebp+16]
	
y_loop:	
	mov ecx,[ebp+4]

	jmp [ebp+32]

_x86return:	
	add esi,[ebp+12]
	add edi,[ebp+28]
	
	dec dword  [ebp+8]
	jnz y_loop

; Restore the registers used by the blitters, necessary for optimized code
	popa
	
	pop ebp

endconvert:	
	ret		



;; Hermes_X86_CPU returns the CPUID flags in eax
	
_Hermes_X86_CPU:
	pushfd
	pop eax
	
	mov ecx,eax
	
	xor eax,040000h
	push eax
	
	popfd
	pushfd

	pop eax
	xor eax,ecx
	jz .L1			; Processor is 386

	push ecx
	popfd

	mov eax,ecx
	xor eax,200000h

	push eax
	popfd
	pushfd

	pop eax
	xor eax,ecx
	je .L1
	
	push ebx

	mov eax,1
	cpuid
	mov eax,edx

	pop ebx

.L1:	
	ret

%ifidn __OUTPUT_FORMAT__,elf
section .note.GNU-stack noalloc noexec nowrite progbits
%endif