pcsx2/common/include/Utilities/MemcpyFast.h

135 lines
5.2 KiB
C

/* PCSX2 - PS2 Emulator for PCs
* Copyright (C) 2002-2010 PCSX2 Dev Team
*
* PCSX2 is free software: you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* PCSX2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with PCSX2.
* If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#ifdef __LINUX__
# include "lnx_memzero.h"
extern "C" void __fastcall memcpy_amd_(void *dest, const void *src, size_t bytes);
extern "C" u8 memcmp_mmx(const void* src1, const void* src2, int cmpsize);
extern "C" void memxor_mmx(void* dst, const void* src1, int cmpsize);
// This can be moved later, but Linux doesn't even compile memcpyFast.cpp, so I figured I'd stick it here for now.
// Quadword Copy! Count is in QWCs (128 bits). Neither source nor dest need to be aligned.
static __forceinline void memcpy_amd_qwc(void *dest, const void *src, size_t qwc)
{
// Optimization Analysis: This code is *nearly* optimal. Do not think that using XMM
// registers will improve copy performance, because they won't. Use of XMMs is only
// warranted in situations where both source and dest are guaranteed aligned to 16 bytes,
// and even then the benefits are typically minimal (sometimes slower depending on the
// amount of data being copied).
//
// Thus: MMX are alignment safe, fast, and widely available. Lets just stick with them.
// --air
// Linux Conversion note:
// This code would benefit nicely from having inline-able GAS syntax, since it should
// allow GCC to optimize the first 3 instructions out of existence in many scenarios.
// And its called enough times to probably merit the extra effort to ensure proper
// optimization. --air
__asm__
(
".intel_syntax noprefix\n"
//"mov ecx, [%[dest]]\n"
//"mov edx, [%[src]]\n"
//"mov eax, [%[qwc]]\n" // keep a copy of count
"mov eax, %[qwc]\n"
"shr eax, 1\n"
"jz memcpy_qwc_1\n" // only one 16 byte block to copy?
"cmp %[qwc], 64\n" // "IN_CACHE_COPY/32"
"jb memcpy_qwc_loop1\n" // small copies should be cached (definite speedup --air)
"memcpy_qwc_loop2:\n" // 32-byte blocks, uncached copy
"prefetchnta [%[src] + 568]\n" // start reading ahead (tested: it helps! --air)
"movq mm0,[%[src]+0]\n" // read 64 bits
"movq mm1,[%[src]+8]\n"
"movq mm2,[%[src]+16]\n"
"movntq [%[dest]+0], mm0\n" // write 64 bits, bypassing the cache
"movntq [%[dest]+8], mm1\n"
"movq mm3,[%[src]+24]\n"
"movntq [%[dest]+16], mm2\n"
"movntq [%[dest]+24], mm3\n"
"add %[src],32\n" // update source pointer
"add %[dest],32\n" // update destination pointer
"sub eax,1\n"
"jnz memcpy_qwc_loop2\n" // last 64-byte block?
"sfence\n" // flush the write buffer
"jmp memcpy_qwc_1\n"
// 32-byte blocks, cached!
// This *is* important. Removing this and using exclusively non-temporal stores
// results in noticeable speed loss!
"memcpy_qwc_loop1:\n"
"prefetchnta [%[src] + 568]\n" // start reading ahead (tested: it helps! --air)
"movq mm0,[%[src]+0]\n" // read 64 bits
"movq mm1,[%[src]+8]\n"
"movq mm2,[%[src]+16]\n"
"movq [%[dest]+0], mm0\n" // write 64 bits, bypassing the cache
"movq [%[dest]+8], mm1\n"
"movq mm3,[%[src]+24]\n"
"movq [%[dest]+16], mm2\n"
"movq [%[dest]+24], mm3\n"
"add %[src],32\n" // update source pointer
"add %[dest],32\n" // update destination pointer
"sub eax,1\n"
"jnz memcpy_qwc_loop1\n" // last 64-byte block?
"memcpy_qwc_1:\n"
"test [%qwc],1\n"
"jz memcpy_qwc_final\n"
"movq mm0,[%[src]]\n"
"movq mm1,[%[src]+8]\n"
"movq [%[dest]], mm0\n"
"movq [%[dest]+8], mm1\n"
"memcpy_qwc_final:\n"
"emms\n" // clean up the MMX state
".att_syntax\n"
: "=&r"(dest), "=&r"(src), "=&r"(qwc)
: [dest]"0"(dest), [src]"1"(src), [qwc]"2"(qwc)
: "memory", "eax", "mm0", "mm1", "mm2", "mm3"
);
}
#else
# include "win_memzero.h"
extern void __fastcall memcpy_amd_(void *dest, const void *src, size_t bytes);
extern void memcpy_amd_qwc(void *dest, const void *src, size_t bytes);
extern u8 memcmp_mmx(const void* src1, const void* src2, int cmpsize);
extern void memxor_mmx(void* dst, const void* src1, int cmpsize);
#endif
// Only used in the Windows version of memzero.h. But it's in Misc.cpp for some reason.
void _memset16_unaligned( void* dest, u16 data, size_t size );
#define memcpy_fast memcpy_amd_ // Fast memcpy
#define memcpy_aligned(d,s,c) memcpy_amd_(d,s,c) // Memcpy with 16-byte Aligned addresses
#define memcpy_const memcpy_amd_ // Memcpy with constant size
#define memcpy_constA memcpy_amd_ // Memcpy with constant size and 16-byte aligned
#define memcpy_qwc(d,s,c) memcpy_amd_qwc(d,s,c)
//#define memcpy_qwc(d,s,c) memcpy_amd_(d,s,c*16)