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5-7% faster SSE2 versions of YUV->RGB conversion functions

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The C-version gets ~7-8% slower in order to match the SSE2
output exactly. The old (now off-by-1) code is kept under
the WEBP_YUV_USE_TABLE flag for reference.

(note that calc rounding precision is slightly better ~= +0.02dB)

on ARM-neon, we somehow recover the ~4% speed that was lost by mimicking
the initial C-version (see https://gerrit.chromium.org/gerrit/#/c/41610)

Change-Id: Ia4363c5ed9b4c9edff5d932b002e57bb7814bf6f
This commit is contained in:
skal
2013-08-19 12:43:53 -07:00
parent ad6ac32d7c
commit df6cebfa9e
4 changed files with 365 additions and 218 deletions
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149
src/dsp/yuv.c
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@ -17,12 +17,8 @@
extern "C" {
#endif
#ifdef WEBP_YUV_USE_TABLE
int16_t VP8kVToR[256], VP8kUToB[256];
int32_t VP8kVToG[256], VP8kUToG[256];
uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN];
uint8_t VP8kClip4Bits[YUV_RANGE_MAX - YUV_RANGE_MIN];
#if defined(WEBP_YUV_USE_TABLE)
static int done = 0;
@ -30,6 +26,11 @@ static WEBP_INLINE uint8_t clip(int v, int max_value) {
return v < 0 ? 0 : v > max_value ? max_value : v;
}
int16_t VP8kVToR[256], VP8kUToB[256];
int32_t VP8kVToG[256], VP8kUToG[256];
uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN];
uint8_t VP8kClip4Bits[YUV_RANGE_MAX - YUV_RANGE_MIN];
void VP8YUVInit(void) {
int i;
if (done) {
@ -70,6 +71,144 @@ void VP8YUVInit(void) {}
#endif // WEBP_YUV_USE_TABLE
//-----------------------------------------------------------------------------
// SSE2 extras
#if defined(WEBP_USE_SSE2)
#ifdef FANCY_UPSAMPLING
#include <emmintrin.h>
#include <string.h> // for memcpy
typedef union { // handy struct for converting SSE2 registers
int32_t i32[4];
uint8_t u8[16];
__m128i m;
} VP8kCstSSE2;
static int done_sse2 = 0;
static VP8kCstSSE2 VP8kUtoRGBA[256], VP8kVtoRGBA[256], VP8kYtoRGBA[256];
void VP8YUVInitSSE2(void) {
if (!done_sse2) {
int i;
for (i = 0; i < 256; ++i) {
VP8kYtoRGBA[i].i32[0] =
VP8kYtoRGBA[i].i32[1] =
VP8kYtoRGBA[i].i32[2] = (i - 16) * kYScale + YUV_HALF2;
VP8kYtoRGBA[i].i32[3] = 0xff << YUV_FIX2;
VP8kUtoRGBA[i].i32[0] = 0;
VP8kUtoRGBA[i].i32[1] = -kUToG * (i - 128);
VP8kUtoRGBA[i].i32[2] = kUToB * (i - 128);
VP8kUtoRGBA[i].i32[3] = 0;
VP8kVtoRGBA[i].i32[0] = kVToR * (i - 128);
VP8kVtoRGBA[i].i32[1] = -kVToG * (i - 128);
VP8kVtoRGBA[i].i32[2] = 0;
VP8kVtoRGBA[i].i32[3] = 0;
}
done_sse2 = 1;
}
}
static WEBP_INLINE __m128i VP8GetRGBA32b(int y, int u, int v) {
const __m128i u_part = _mm_loadu_si128(&VP8kUtoRGBA[u].m);
const __m128i v_part = _mm_loadu_si128(&VP8kVtoRGBA[v].m);
const __m128i y_part = _mm_loadu_si128(&VP8kYtoRGBA[y].m);
const __m128i uv_part = _mm_add_epi32(u_part, v_part);
const __m128i rgba1 = _mm_add_epi32(y_part, uv_part);
const __m128i rgba2 = _mm_srai_epi32(rgba1, YUV_FIX2);
return rgba2;
}
static WEBP_INLINE void VP8YuvToRgbSSE2(uint8_t y, uint8_t u, uint8_t v,
uint8_t* const rgb) {
const __m128i tmp0 = VP8GetRGBA32b(y, u, v);
const __m128i tmp1 = _mm_packs_epi32(tmp0, tmp0);
const __m128i tmp2 = _mm_packus_epi16(tmp1, tmp1);
// Note: we store 8 bytes at a time, not 3 bytes! -> memory stomp
_mm_storel_epi64((__m128i*)rgb, tmp2);
}
static WEBP_INLINE void VP8YuvToBgrSSE2(uint8_t y, uint8_t u, uint8_t v,
uint8_t* const bgr) {
const __m128i tmp0 = VP8GetRGBA32b(y, u, v);
const __m128i tmp1 = _mm_shuffle_epi32(tmp0, _MM_SHUFFLE(3, 0, 1, 2));
const __m128i tmp2 = _mm_packs_epi32(tmp1, tmp1);
const __m128i tmp3 = _mm_packus_epi16(tmp2, tmp2);
// Note: we store 8 bytes at a time, not 3 bytes! -> memory stomp
_mm_storel_epi64((__m128i*)bgr, tmp3);
}
void VP8YuvToRgba32(const uint8_t* y, const uint8_t* u, const uint8_t* v,
uint8_t* dst) {
int n;
for (n = 0; n < 32; n += 4) {
const __m128i tmp0_1 = VP8GetRGBA32b(y[n + 0], u[n + 0], v[n + 0]);
const __m128i tmp0_2 = VP8GetRGBA32b(y[n + 1], u[n + 1], v[n + 1]);
const __m128i tmp0_3 = VP8GetRGBA32b(y[n + 2], u[n + 2], v[n + 2]);
const __m128i tmp0_4 = VP8GetRGBA32b(y[n + 3], u[n + 3], v[n + 3]);
const __m128i tmp1_1 = _mm_packs_epi32(tmp0_1, tmp0_2);
const __m128i tmp1_2 = _mm_packs_epi32(tmp0_3, tmp0_4);
const __m128i tmp2 = _mm_packus_epi16(tmp1_1, tmp1_2);
_mm_storeu_si128((__m128i*)dst, tmp2);
dst += 4 * 4;
}
}
void VP8YuvToBgra32(const uint8_t* y, const uint8_t* u, const uint8_t* v,
uint8_t* dst) {
int n;
for (n = 0; n < 32; n += 2) {
const __m128i tmp0_1 = VP8GetRGBA32b(y[n + 0], u[n + 0], v[n + 0]);
const __m128i tmp0_2 = VP8GetRGBA32b(y[n + 1], u[n + 1], v[n + 1]);
const __m128i tmp1_1 = _mm_shuffle_epi32(tmp0_1, _MM_SHUFFLE(3, 0, 1, 2));
const __m128i tmp1_2 = _mm_shuffle_epi32(tmp0_2, _MM_SHUFFLE(3, 0, 1, 2));
const __m128i tmp2_1 = _mm_packs_epi32(tmp1_1, tmp1_2);
const __m128i tmp3 = _mm_packus_epi16(tmp2_1, tmp2_1);
_mm_storel_epi64((__m128i*)dst, tmp3);
dst += 4 * 2;
}
}
void VP8YuvToRgb32(const uint8_t* y, const uint8_t* u, const uint8_t* v,
uint8_t* dst) {
int n;
uint8_t tmp0[2 * 3 + 5 + 15];
uint8_t* const tmp = (uint8_t*)((uintptr_t)(tmp0 + 15) & ~15); // align
for (n = 0; n < 30; ++n) { // we directly stomp the *dst memory
VP8YuvToRgbSSE2(y[n], u[n], v[n], dst + n * 3);
}
// Last two pixels are special: we write in a tmp buffer before sending
// to dst.
VP8YuvToRgbSSE2(y[n + 0], u[n + 0], v[n + 0], tmp + 0);
VP8YuvToRgbSSE2(y[n + 1], u[n + 1], v[n + 1], tmp + 3);
memcpy(dst + n * 3, tmp, 2 * 3);
}
void VP8YuvToBgr32(const uint8_t* y, const uint8_t* u, const uint8_t* v,
uint8_t* dst) {
int n;
uint8_t tmp0[2 * 3 + 5 + 15];
uint8_t* const tmp = (uint8_t*)((uintptr_t)(tmp0 + 15) & ~15); // align
for (n = 0; n < 30; ++n) {
VP8YuvToBgrSSE2(y[n], u[n], v[n], dst + n * 3);
}
VP8YuvToBgrSSE2(y[n + 0], u[n + 0], v[n + 0], tmp + 0);
VP8YuvToBgrSSE2(y[n + 1], u[n + 1], v[n + 1], tmp + 3);
memcpy(dst + n * 3, tmp, 2 * 3);
}
#else
void VP8YUVInitSSE2(void) {}
#endif // FANCY_UPSAMPLING
#endif // WEBP_USE_SSE2
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif