dhewm3-sdk/idlib/math/Simd_3DNow.cpp
dhewg afebd7e1e5 Untangle the epic precompiled.h mess
Don't include the lazy precompiled.h everywhere, only what's
required for the compilation unit.
platform.h needs to be included instead to provide all essential
defines and types.
All includes use the relative path to the neo or the game
specific root.
Move all idlib related includes from idlib/Lib.h to precompiled.h.
precompiled.h still exists for the MFC stuff in tools/.
Add some missing header guards.
2018-08-20 01:46:28 +02:00

293 lines
10 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code ("Doom 3 Source Code").
Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 Source Code 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 Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "sys/platform.h"
#include "idlib/math/Simd_3DNow.h"
//===============================================================
//
// 3DNow! implementation of idSIMDProcessor
//
//===============================================================
#ifdef _MSC_VER
/*
============
idSIMD_3DNow::GetName
============
*/
const char * idSIMD_3DNow::GetName( void ) const {
return "MMX & 3DNow!";
}
// Very optimized memcpy() routine for all AMD Athlon and Duron family.
// This code uses any of FOUR different basic copy methods, depending
// on the transfer size.
// NOTE: Since this code uses MOVNTQ (also known as "Non-Temporal MOV" or
// "Streaming Store"), and also uses the software prefetchnta instructions,
// be sure you're running on Athlon/Duron or other recent CPU before calling!
#define TINY_BLOCK_COPY 64 // upper limit for movsd type copy
// The smallest copy uses the X86 "movsd" instruction, in an optimized
// form which is an "unrolled loop".
#define IN_CACHE_COPY 64 * 1024 // upper limit for movq/movq copy w/SW prefetch
// Next is a copy that uses the MMX registers to copy 8 bytes at a time,
// also using the "unrolled loop" optimization. This code uses
// the software prefetch instruction to get the data into the cache.
#define UNCACHED_COPY 197 * 1024 // upper limit for movq/movntq w/SW prefetch
// For larger blocks, which will spill beyond the cache, it's faster to
// use the Streaming Store instruction MOVNTQ. This write instruction
// bypasses the cache and writes straight to main memory. This code also
// uses the software prefetch instruction to pre-read the data.
// USE 64 * 1024 FOR THIS VALUE IF YOU'RE ALWAYS FILLING A "CLEAN CACHE"
#define BLOCK_PREFETCH_COPY infinity // no limit for movq/movntq w/block prefetch
#define CACHEBLOCK 80h // number of 64-byte blocks (cache lines) for block prefetch
// For the largest size blocks, a special technique called Block Prefetch
// can be used to accelerate the read operations. Block Prefetch reads
// one address per cache line, for a series of cache lines, in a short loop.
// This is faster than using software prefetch. The technique is great for
// getting maximum read bandwidth, especially in DDR memory systems.
/*
================
idSIMD_3DNow::Memcpy
optimized memory copy routine that handles all alignment cases and block sizes efficiently
================
*/
void VPCALL idSIMD_3DNow::Memcpy( void *dest, const void *src, const int n ) {
__asm {
mov ecx, [n] // number of bytes to copy
mov edi, [dest] // destination
mov esi, [src] // source
mov ebx, ecx // keep a copy of count
cld
cmp ecx, TINY_BLOCK_COPY
jb $memcpy_ic_3 // tiny? skip mmx copy
cmp ecx, 32*1024 // don't align between 32k-64k because
jbe $memcpy_do_align // it appears to be slower
cmp ecx, 64*1024
jbe $memcpy_align_done
$memcpy_do_align:
mov ecx, 8 // a trick that's faster than rep movsb...
sub ecx, edi // align destination to qword
and ecx, 111b // get the low bits
sub ebx, ecx // update copy count
neg ecx // set up to jump into the array
add ecx, offset $memcpy_align_done
jmp ecx // jump to array of movsb's
align 4
movsb
movsb
movsb
movsb
movsb
movsb
movsb
movsb
$memcpy_align_done: // destination is dword aligned
mov ecx, ebx // number of bytes left to copy
shr ecx, 6 // get 64-byte block count
jz $memcpy_ic_2 // finish the last few bytes
cmp ecx, IN_CACHE_COPY/64 // too big 4 cache? use uncached copy
jae $memcpy_uc_test
// This is small block copy that uses the MMX registers to copy 8 bytes
// at a time. It uses the "unrolled loop" optimization, and also uses
// the software prefetch instruction to get the data into the cache.
align 16
$memcpy_ic_1: // 64-byte block copies, in-cache copy
prefetchnta [esi + (200*64/34+192)] // start reading ahead
movq mm0, [esi+0] // read 64 bits
movq mm1, [esi+8]
movq [edi+0], mm0 // write 64 bits
movq [edi+8], mm1 // note: the normal movq writes the
movq mm2, [esi+16] // data to cache; a cache line will be
movq mm3, [esi+24] // allocated as needed, to store the data
movq [edi+16], mm2
movq [edi+24], mm3
movq mm0, [esi+32]
movq mm1, [esi+40]
movq [edi+32], mm0
movq [edi+40], mm1
movq mm2, [esi+48]
movq mm3, [esi+56]
movq [edi+48], mm2
movq [edi+56], mm3
add esi, 64 // update source pointer
add edi, 64 // update destination pointer
dec ecx // count down
jnz $memcpy_ic_1 // last 64-byte block?
$memcpy_ic_2:
mov ecx, ebx // has valid low 6 bits of the byte count
$memcpy_ic_3:
shr ecx, 2 // dword count
and ecx, 1111b // only look at the "remainder" bits
neg ecx // set up to jump into the array
add ecx, offset $memcpy_last_few
jmp ecx // jump to array of movsd's
$memcpy_uc_test:
cmp ecx, UNCACHED_COPY/64 // big enough? use block prefetch copy
jae $memcpy_bp_1
$memcpy_64_test:
or ecx, ecx // tail end of block prefetch will jump here
jz $memcpy_ic_2 // no more 64-byte blocks left
// For larger blocks, which will spill beyond the cache, it's faster to
// use the Streaming Store instruction MOVNTQ. This write instruction
// bypasses the cache and writes straight to main memory. This code also
// uses the software prefetch instruction to pre-read the data.
align 16
$memcpy_uc_1: // 64-byte blocks, uncached copy
prefetchnta [esi + (200*64/34+192)] // start reading ahead
movq mm0,[esi+0] // read 64 bits
add edi,64 // update destination pointer
movq mm1,[esi+8]
add esi,64 // update source pointer
movq mm2,[esi-48]
movntq [edi-64], mm0 // write 64 bits, bypassing the cache
movq mm0,[esi-40] // note: movntq also prevents the CPU
movntq [edi-56], mm1 // from READING the destination address
movq mm1,[esi-32] // into the cache, only to be over-written
movntq [edi-48], mm2 // so that also helps performance
movq mm2,[esi-24]
movntq [edi-40], mm0
movq mm0,[esi-16]
movntq [edi-32], mm1
movq mm1,[esi-8]
movntq [edi-24], mm2
movntq [edi-16], mm0
dec ecx
movntq [edi-8], mm1
jnz $memcpy_uc_1 // last 64-byte block?
jmp $memcpy_ic_2 // almost done
// For the largest size blocks, a special technique called Block Prefetch
// can be used to accelerate the read operations. Block Prefetch reads
// one address per cache line, for a series of cache lines, in a short loop.
// This is faster than using software prefetch, in this case.
// The technique is great for getting maximum read bandwidth,
// especially in DDR memory systems.
$memcpy_bp_1: // large blocks, block prefetch copy
cmp ecx, CACHEBLOCK // big enough to run another prefetch loop?
jl $memcpy_64_test // no, back to regular uncached copy
mov eax, CACHEBLOCK / 2 // block prefetch loop, unrolled 2X
add esi, CACHEBLOCK * 64 // move to the top of the block
align 16
$memcpy_bp_2:
mov edx, [esi-64] // grab one address per cache line
mov edx, [esi-128] // grab one address per cache line
sub esi, 128 // go reverse order
dec eax // count down the cache lines
jnz $memcpy_bp_2 // keep grabbing more lines into cache
mov eax, CACHEBLOCK // now that it's in cache, do the copy
align 16
$memcpy_bp_3:
movq mm0, [esi ] // read 64 bits
movq mm1, [esi+ 8]
movq mm2, [esi+16]
movq mm3, [esi+24]
movq mm4, [esi+32]
movq mm5, [esi+40]
movq mm6, [esi+48]
movq mm7, [esi+56]
add esi, 64 // update source pointer
movntq [edi ], mm0 // write 64 bits, bypassing cache
movntq [edi+ 8], mm1 // note: movntq also prevents the CPU
movntq [edi+16], mm2 // from READING the destination address
movntq [edi+24], mm3 // into the cache, only to be over-written,
movntq [edi+32], mm4 // so that also helps performance
movntq [edi+40], mm5
movntq [edi+48], mm6
movntq [edi+56], mm7
add edi, 64 // update dest pointer
dec eax // count down
jnz $memcpy_bp_3 // keep copying
sub ecx, CACHEBLOCK // update the 64-byte block count
jmp $memcpy_bp_1 // keep processing chunks
// The smallest copy uses the X86 "movsd" instruction, in an optimized
// form which is an "unrolled loop". Then it handles the last few bytes.
align 4
movsd
movsd // perform last 1-15 dword copies
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd // perform last 1-7 dword copies
movsd
movsd
movsd
movsd
movsd
movsd
$memcpy_last_few: // dword aligned from before movsd's
mov ecx, ebx // has valid low 2 bits of the byte count
and ecx, 11b // the last few cows must come home
jz $memcpy_final // no more, let's leave
rep movsb // the last 1, 2, or 3 bytes
$memcpy_final:
emms // clean up the MMX state
sfence // flush the write buffer
mov eax, [dest] // ret value = destination pointer
}
}
#endif /* _WIN32 */