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FFmpeg/libswscale/x86/hscale_fast_bilinear_simd.c
Andreas Cadhalpun 319438e2f2 swscale: save ebx register when it is not available
Configure checks if the ebx register can be used for asm and it has to
be saved if and only if this is not the case.
Without this the build fails when configuring with --toolchain=hardened
--disable-pic on i386 using gcc 4.8:
error: PIC register clobbered by '%ebx' in 'asm'

In that case gcc 4.8 reserves the ebx register for the GOT needed for
PIE, so it can't be used in asm directly.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
2016-12-21 01:26:10 +01:00

360 lines
14 KiB
C

/*
* Copyright (C) 2001-2003 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg 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 Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "../swscale_internal.h"
#include "libavutil/x86/asm.h"
#include "libavutil/x86/cpu.h"
#define RET 0xC3 // near return opcode for x86
#define PREFETCH "prefetchnta"
#if HAVE_INLINE_ASM
av_cold int ff_init_hscaler_mmxext(int dstW, int xInc, uint8_t *filterCode,
int16_t *filter, int32_t *filterPos,
int numSplits)
{
uint8_t *fragmentA;
x86_reg imm8OfPShufW1A;
x86_reg imm8OfPShufW2A;
x86_reg fragmentLengthA;
uint8_t *fragmentB;
x86_reg imm8OfPShufW1B;
x86_reg imm8OfPShufW2B;
x86_reg fragmentLengthB;
int fragmentPos;
int xpos, i;
// create an optimized horizontal scaling routine
/* This scaler is made of runtime-generated MMXEXT code using specially tuned
* pshufw instructions. For every four output pixels, if four input pixels
* are enough for the fast bilinear scaling, then a chunk of fragmentB is
* used. If five input pixels are needed, then a chunk of fragmentA is used.
*/
// code fragment
__asm__ volatile (
"jmp 9f \n\t"
// Begin
"0: \n\t"
"movq (%%"FF_REG_d", %%"FF_REG_a"), %%mm3 \n\t"
"movd (%%"FF_REG_c", %%"FF_REG_S"), %%mm0 \n\t"
"movd 1(%%"FF_REG_c", %%"FF_REG_S"), %%mm1 \n\t"
"punpcklbw %%mm7, %%mm1 \n\t"
"punpcklbw %%mm7, %%mm0 \n\t"
"pshufw $0xFF, %%mm1, %%mm1 \n\t"
"1: \n\t"
"pshufw $0xFF, %%mm0, %%mm0 \n\t"
"2: \n\t"
"psubw %%mm1, %%mm0 \n\t"
"movl 8(%%"FF_REG_b", %%"FF_REG_a"), %%esi \n\t"
"pmullw %%mm3, %%mm0 \n\t"
"psllw $7, %%mm1 \n\t"
"paddw %%mm1, %%mm0 \n\t"
"movq %%mm0, (%%"FF_REG_D", %%"FF_REG_a") \n\t"
"add $8, %%"FF_REG_a" \n\t"
// End
"9: \n\t"
"lea " LOCAL_MANGLE(0b) ", %0 \n\t"
"lea " LOCAL_MANGLE(1b) ", %1 \n\t"
"lea " LOCAL_MANGLE(2b) ", %2 \n\t"
"dec %1 \n\t"
"dec %2 \n\t"
"sub %0, %1 \n\t"
"sub %0, %2 \n\t"
"lea " LOCAL_MANGLE(9b) ", %3 \n\t"
"sub %0, %3 \n\t"
: "=r" (fragmentA), "=r" (imm8OfPShufW1A), "=r" (imm8OfPShufW2A),
"=r" (fragmentLengthA)
);
__asm__ volatile (
"jmp 9f \n\t"
// Begin
"0: \n\t"
"movq (%%"FF_REG_d", %%"FF_REG_a"), %%mm3 \n\t"
"movd (%%"FF_REG_c", %%"FF_REG_S"), %%mm0 \n\t"
"punpcklbw %%mm7, %%mm0 \n\t"
"pshufw $0xFF, %%mm0, %%mm1 \n\t"
"1: \n\t"
"pshufw $0xFF, %%mm0, %%mm0 \n\t"
"2: \n\t"
"psubw %%mm1, %%mm0 \n\t"
"movl 8(%%"FF_REG_b", %%"FF_REG_a"), %%esi \n\t"
"pmullw %%mm3, %%mm0 \n\t"
"psllw $7, %%mm1 \n\t"
"paddw %%mm1, %%mm0 \n\t"
"movq %%mm0, (%%"FF_REG_D", %%"FF_REG_a") \n\t"
"add $8, %%"FF_REG_a" \n\t"
// End
"9: \n\t"
"lea " LOCAL_MANGLE(0b) ", %0 \n\t"
"lea " LOCAL_MANGLE(1b) ", %1 \n\t"
"lea " LOCAL_MANGLE(2b) ", %2 \n\t"
"dec %1 \n\t"
"dec %2 \n\t"
"sub %0, %1 \n\t"
"sub %0, %2 \n\t"
"lea " LOCAL_MANGLE(9b) ", %3 \n\t"
"sub %0, %3 \n\t"
: "=r" (fragmentB), "=r" (imm8OfPShufW1B), "=r" (imm8OfPShufW2B),
"=r" (fragmentLengthB)
);
xpos = 0; // lumXInc/2 - 0x8000; // difference between pixel centers
fragmentPos = 0;
for (i = 0; i < dstW / numSplits; i++) {
int xx = xpos >> 16;
if ((i & 3) == 0) {
int a = 0;
int b = ((xpos + xInc) >> 16) - xx;
int c = ((xpos + xInc * 2) >> 16) - xx;
int d = ((xpos + xInc * 3) >> 16) - xx;
int inc = (d + 1 < 4);
uint8_t *fragment = inc ? fragmentB : fragmentA;
x86_reg imm8OfPShufW1 = inc ? imm8OfPShufW1B : imm8OfPShufW1A;
x86_reg imm8OfPShufW2 = inc ? imm8OfPShufW2B : imm8OfPShufW2A;
x86_reg fragmentLength = inc ? fragmentLengthB : fragmentLengthA;
int maxShift = 3 - (d + inc);
int shift = 0;
if (filterCode) {
filter[i] = ((xpos & 0xFFFF) ^ 0xFFFF) >> 9;
filter[i + 1] = (((xpos + xInc) & 0xFFFF) ^ 0xFFFF) >> 9;
filter[i + 2] = (((xpos + xInc * 2) & 0xFFFF) ^ 0xFFFF) >> 9;
filter[i + 3] = (((xpos + xInc * 3) & 0xFFFF) ^ 0xFFFF) >> 9;
filterPos[i / 2] = xx;
memcpy(filterCode + fragmentPos, fragment, fragmentLength);
filterCode[fragmentPos + imm8OfPShufW1] = (a + inc) |
((b + inc) << 2) |
((c + inc) << 4) |
((d + inc) << 6);
filterCode[fragmentPos + imm8OfPShufW2] = a | (b << 2) |
(c << 4) |
(d << 6);
if (i + 4 - inc >= dstW)
shift = maxShift; // avoid overread
else if ((filterPos[i / 2] & 3) <= maxShift)
shift = filterPos[i / 2] & 3; // align
if (shift && i >= shift) {
filterCode[fragmentPos + imm8OfPShufW1] += 0x55 * shift;
filterCode[fragmentPos + imm8OfPShufW2] += 0x55 * shift;
filterPos[i / 2] -= shift;
}
}
fragmentPos += fragmentLength;
if (filterCode)
filterCode[fragmentPos] = RET;
}
xpos += xInc;
}
if (filterCode)
filterPos[((i / 2) + 1) & (~1)] = xpos >> 16; // needed to jump to the next part
return fragmentPos + 1;
}
void ff_hyscale_fast_mmxext(SwsContext *c, int16_t *dst,
int dstWidth, const uint8_t *src,
int srcW, int xInc)
{
int32_t *filterPos = c->hLumFilterPos;
int16_t *filter = c->hLumFilter;
void *mmxextFilterCode = c->lumMmxextFilterCode;
int i;
#if ARCH_X86_64
uint64_t retsave;
#else
#if !HAVE_EBX_AVAILABLE
uint64_t ebxsave;
#endif
#endif
__asm__ volatile(
#if ARCH_X86_64
"mov -8(%%rsp), %%"FF_REG_a" \n\t"
"mov %%"FF_REG_a", %5 \n\t" // retsave
#else
#if !HAVE_EBX_AVAILABLE
"mov %%"FF_REG_b", %5 \n\t" // ebxsave
#endif
#endif
"pxor %%mm7, %%mm7 \n\t"
"mov %0, %%"FF_REG_c" \n\t"
"mov %1, %%"FF_REG_D" \n\t"
"mov %2, %%"FF_REG_d" \n\t"
"mov %3, %%"FF_REG_b" \n\t"
"xor %%"FF_REG_a", %%"FF_REG_a" \n\t" // i
PREFETCH" (%%"FF_REG_c") \n\t"
PREFETCH" 32(%%"FF_REG_c") \n\t"
PREFETCH" 64(%%"FF_REG_c") \n\t"
#if ARCH_X86_64
#define CALL_MMXEXT_FILTER_CODE \
"movl (%%"FF_REG_b"), %%esi \n\t"\
"call *%4 \n\t"\
"movl (%%"FF_REG_b", %%"FF_REG_a"), %%esi \n\t"\
"add %%"FF_REG_S", %%"FF_REG_c" \n\t"\
"add %%"FF_REG_a", %%"FF_REG_D" \n\t"\
"xor %%"FF_REG_a", %%"FF_REG_a" \n\t"\
#else
#define CALL_MMXEXT_FILTER_CODE \
"movl (%%"FF_REG_b"), %%esi \n\t"\
"call *%4 \n\t"\
"addl (%%"FF_REG_b", %%"FF_REG_a"), %%"FF_REG_c" \n\t"\
"add %%"FF_REG_a", %%"FF_REG_D" \n\t"\
"xor %%"FF_REG_a", %%"FF_REG_a" \n\t"\
#endif /* ARCH_X86_64 */
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
#if ARCH_X86_64
"mov %5, %%"FF_REG_a" \n\t"
"mov %%"FF_REG_a", -8(%%rsp) \n\t"
#else
#if !HAVE_EBX_AVAILABLE
"mov %5, %%"FF_REG_b" \n\t"
#endif
#endif
:: "m" (src), "m" (dst), "m" (filter), "m" (filterPos),
"m" (mmxextFilterCode)
#if ARCH_X86_64
,"m"(retsave)
#else
#if !HAVE_EBX_AVAILABLE
,"m" (ebxsave)
#endif
#endif
: "%"FF_REG_a, "%"FF_REG_c, "%"FF_REG_d, "%"FF_REG_S, "%"FF_REG_D
#if ARCH_X86_64 || HAVE_EBX_AVAILABLE
,"%"FF_REG_b
#endif
);
for (i=dstWidth-1; (i*xInc)>>16 >=srcW-1; i--)
dst[i] = src[srcW-1]*128;
}
void ff_hcscale_fast_mmxext(SwsContext *c, int16_t *dst1, int16_t *dst2,
int dstWidth, const uint8_t *src1,
const uint8_t *src2, int srcW, int xInc)
{
int32_t *filterPos = c->hChrFilterPos;
int16_t *filter = c->hChrFilter;
void *mmxextFilterCode = c->chrMmxextFilterCode;
int i;
#if ARCH_X86_64
DECLARE_ALIGNED(8, uint64_t, retsave);
#else
#if !HAVE_EBX_AVAILABLE
DECLARE_ALIGNED(8, uint64_t, ebxsave);
#endif
#endif
__asm__ volatile(
#if ARCH_X86_64
"mov -8(%%rsp), %%"FF_REG_a" \n\t"
"mov %%"FF_REG_a", %7 \n\t" // retsave
#else
#if !HAVE_EBX_AVAILABLE
"mov %%"FF_REG_b", %7 \n\t" // ebxsave
#endif
#endif
"pxor %%mm7, %%mm7 \n\t"
"mov %0, %%"FF_REG_c" \n\t"
"mov %1, %%"FF_REG_D" \n\t"
"mov %2, %%"FF_REG_d" \n\t"
"mov %3, %%"FF_REG_b" \n\t"
"xor %%"FF_REG_a", %%"FF_REG_a" \n\t" // i
PREFETCH" (%%"FF_REG_c") \n\t"
PREFETCH" 32(%%"FF_REG_c") \n\t"
PREFETCH" 64(%%"FF_REG_c") \n\t"
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
"xor %%"FF_REG_a", %%"FF_REG_a" \n\t" // i
"mov %5, %%"FF_REG_c" \n\t" // src2
"mov %6, %%"FF_REG_D" \n\t" // dst2
PREFETCH" (%%"FF_REG_c") \n\t"
PREFETCH" 32(%%"FF_REG_c") \n\t"
PREFETCH" 64(%%"FF_REG_c") \n\t"
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
CALL_MMXEXT_FILTER_CODE
#if ARCH_X86_64
"mov %7, %%"FF_REG_a" \n\t"
"mov %%"FF_REG_a", -8(%%rsp) \n\t"
#else
#if !HAVE_EBX_AVAILABLE
"mov %7, %%"FF_REG_b" \n\t"
#endif
#endif
:: "m" (src1), "m" (dst1), "m" (filter), "m" (filterPos),
"m" (mmxextFilterCode), "m" (src2), "m"(dst2)
#if ARCH_X86_64
,"m"(retsave)
#else
#if !HAVE_EBX_AVAILABLE
,"m" (ebxsave)
#endif
#endif
: "%"FF_REG_a, "%"FF_REG_c, "%"FF_REG_d, "%"FF_REG_S, "%"FF_REG_D
#if ARCH_X86_64 || HAVE_EBX_AVAILABLE
,"%"FF_REG_b
#endif
);
for (i=dstWidth-1; (i*xInc)>>16 >=srcW-1; i--) {
dst1[i] = src1[srcW-1]*128;
dst2[i] = src2[srcW-1]*128;
}
}
#endif //HAVE_INLINE_ASM