Mercurial > sdl-ios-xcode
view src/hermes/mmx_main.asm @ 689:5bb080d35049
Date: Tue, 19 Aug 2003 17:57:00 +0200
From: Stephane Marchesin
Subject: Re: [SDL] [patch] MMX alpha blit patches with MMX detection
I think everything is correct now. I've done as much testing as I could,
but some real-world testing wouldn't hurt, I think.
The patch is here : http://icps.u-strasbg.fr/~marchesin/sdl_mmxblit.patch
If you do byte-by-byte comparison of the output between C and MMX
functions, you'll notice that the results for 555 and 565 RGB alpha
blits aren't exactly the same. This is because MMX functions for 555 and
565 RGB have an higher accuracy. If you want the exact same behaviour
that's possible by masking the three lower alpha bits in the MMX
functions. Just ask !
I removed one MMX function because after I fixed it to match its C
equivalent, it revealed to be slower than the C version on a PIII
(although a bit faster on an Athlon XP).
I've also added MMX and PIII replacements for SDL_memcpy. Those provide
some speed up in testvidinfo -benchmark (at least for me, under linux &
X11).
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 22 Aug 2003 05:51:19 +0000 |
parents | 74212992fb08 |
children | da33b7e6d181 |
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; ; mmx format converter main loops for HERMES ; Some routines Copyright (c) 1998 Christian Nentwich (c.nentwich@cs.ucl.ac.uk) ; This source code is licensed under the GNU LGPL ; ; Please refer to the file COPYING.LIB contained in the distribution for ; licensing conditions ; BITS 32 GLOBAL _ConvertMMX GLOBAL _mmxreturn SECTION .text ;; _ConvertMMX: ;; [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 _ConvertMMX: 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] _mmxreturn: 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: emms ret