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fix rescaling rounding inaccuracy

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We should be using 'floor' when doing the final divide.

-> new MACRO is MULT_FIX_FLOOR()

     XXX*** Mips code is DISABLED for now ***XXX

I'll update and re-enable it in a later
patch, since this code needs some refactoring first.

BUG=oss-fuzz:9179

Change-Id: Ic0693cdca4e71f5beab1029475e35c4d06b12d13
(cherry picked from commit 2563db4759)
This commit is contained in:
Pascal Massimino 2018-07-10 17:27:21 -07:00 committed by James Zern
parent 99d0790233
commit 916aac82c5
6 changed files with 65 additions and 13 deletions
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4
src/dsp/rescaler.c
View File

@ -21,6 +21,7 @@
#define ROUNDER (WEBP_RESCALER_ONE >> 1)
#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
#define MULT_FIX_FLOOR(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
//------------------------------------------------------------------------------
// Row import
@ -138,7 +139,7 @@ void WebPRescalerExportRowShrink_C(WebPRescaler* const wrk) {
if (yscale) {
for (x_out = 0; x_out < x_out_max; ++x_out) {
const uint32_t frac = (uint32_t)MULT_FIX(frow[x_out], yscale);
const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale);
const int v = (int)MULT_FIX_FLOOR(irow[x_out] - frac, wrk->fxy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
irow[x_out] = frac; // new fractional start
@ -153,6 +154,7 @@ void WebPRescalerExportRowShrink_C(WebPRescaler* const wrk) {
}
}
#undef MULT_FIX_FLOOR
#undef MULT_FIX
#undef ROUNDER

4
src/dsp/rescaler_mips32.c
View File

@ -209,6 +209,7 @@ static void ExportRowExpand_MIPS32(WebPRescaler* const wrk) {
}
}
#if 0 // disabled for now. TODO(skal): make match the C-code
static void ExportRowShrink_MIPS32(WebPRescaler* const wrk) {
const int x_out_max = wrk->dst_width * wrk->num_channels;
uint8_t* dst = wrk->dst;
@ -273,6 +274,7 @@ static void ExportRowShrink_MIPS32(WebPRescaler* const wrk) {
);
}
}
#endif // 0
//------------------------------------------------------------------------------
// Entry point
@ -283,7 +285,7 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitMIPS32(void) {
WebPRescalerImportRowExpand = ImportRowExpand_MIPS32;
WebPRescalerImportRowShrink = ImportRowShrink_MIPS32;
WebPRescalerExportRowExpand = ExportRowExpand_MIPS32;
WebPRescalerExportRowShrink = ExportRowShrink_MIPS32;
// WebPRescalerExportRowShrink = ExportRowShrink_MIPS32;
}
#else // !WEBP_USE_MIPS32

10
src/dsp/rescaler_mips_dsp_r2.c
View File

@ -20,10 +20,12 @@
#define ROUNDER (WEBP_RESCALER_ONE >> 1)
#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
#define MULT_FIX_FLOOR(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
//------------------------------------------------------------------------------
// Row export
#if 0 // disabled for now. TODO(skal): make match the C-code
static void ExportRowShrink_MIPSdspR2(WebPRescaler* const wrk) {
int i;
const int x_out_max = wrk->dst_width * wrk->num_channels;
@ -106,7 +108,7 @@ static void ExportRowShrink_MIPSdspR2(WebPRescaler* const wrk) {
}
for (i = 0; i < (x_out_max & 0x3); ++i) {
const uint32_t frac = (uint32_t)MULT_FIX(*frow++, yscale);
const int v = (int)MULT_FIX(*irow - frac, wrk->fxy_scale);
const int v = (int)MULT_FIX_FLOOR(*irow - frac, wrk->fxy_scale);
assert(v >= 0 && v <= 255);
*dst++ = v;
*irow++ = frac; // new fractional start
@ -154,13 +156,14 @@ static void ExportRowShrink_MIPSdspR2(WebPRescaler* const wrk) {
);
}
for (i = 0; i < (x_out_max & 0x3); ++i) {
const int v = (int)MULT_FIX(*irow, wrk->fxy_scale);
const int v = (int)MULT_FIX_FLOOR(*irow, wrk->fxy_scale);
assert(v >= 0 && v <= 255);
*dst++ = v;
*irow++ = 0;
}
}
}
#endif // 0
static void ExportRowExpand_MIPSdspR2(WebPRescaler* const wrk) {
int i;
@ -294,6 +297,7 @@ static void ExportRowExpand_MIPSdspR2(WebPRescaler* const wrk) {
}
}
#undef MULT_FIX_FLOOR
#undef MULT_FIX
#undef ROUNDER
@ -304,7 +308,7 @@ extern void WebPRescalerDspInitMIPSdspR2(void);
WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitMIPSdspR2(void) {
WebPRescalerExportRowExpand = ExportRowExpand_MIPSdspR2;
WebPRescalerExportRowShrink = ExportRowShrink_MIPSdspR2;
// WebPRescalerExportRowShrink = ExportRowShrink_MIPSdspR2;
}
#else // !WEBP_USE_MIPS_DSP_R2

7
src/dsp/rescaler_msa.c
View File

@ -22,6 +22,7 @@
#define ROUNDER (WEBP_RESCALER_ONE >> 1)
#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
#define MULT_FIX_FLOOR(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
#define CALC_MULT_FIX_16(in0, in1, in2, in3, scale, shift, dst) do { \
v4u32 tmp0, tmp1, tmp2, tmp3; \
@ -262,6 +263,7 @@ static void RescalerExportRowExpand_MIPSdspR2(WebPRescaler* const wrk) {
}
}
#if 0 // disabled for now. TODO(skal): make match the C-code
static WEBP_INLINE void ExportRowShrink_0(const uint32_t* frow, uint32_t* irow,
uint8_t* dst, int length,
const uint32_t yscale,
@ -341,7 +343,7 @@ static WEBP_INLINE void ExportRowShrink_0(const uint32_t* frow, uint32_t* irow,
}
for (x_out = 0; x_out < length; ++x_out) {
const uint32_t frac = (uint32_t)MULT_FIX(frow[x_out], yscale);
const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale);
const int v = (int)MULT_FIX_FLOOR(irow[x_out] - frac, wrk->fxy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
irow[x_out] = frac;
@ -426,6 +428,7 @@ static void RescalerExportRowShrink_MIPSdspR2(WebPRescaler* const wrk) {
ExportRowShrink_1(irow, dst, x_out_max, wrk);
}
}
#endif // 0
//------------------------------------------------------------------------------
// Entry point
@ -434,7 +437,7 @@ extern void WebPRescalerDspInitMSA(void);
WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitMSA(void) {
WebPRescalerExportRowExpand = RescalerExportRowExpand_MIPSdspR2;
WebPRescalerExportRowShrink = RescalerExportRowShrink_MIPSdspR2;
// WebPRescalerExportRowShrink = RescalerExportRowShrink_MIPSdspR2;
}
#else // !WEBP_USE_MSA

18
src/dsp/rescaler_neon.c
View File

@ -22,6 +22,7 @@
#define ROUNDER (WEBP_RESCALER_ONE >> 1)
#define MULT_FIX_C(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
#define MULT_FIX_FLOOR_C(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
#define LOAD_32x4(SRC, DST) const uint32x4_t DST = vld1q_u32((SRC))
#define LOAD_32x8(SRC, DST0, DST1) \
@ -35,8 +36,11 @@
#if (WEBP_RESCALER_RFIX == 32)
#define MAKE_HALF_CST(C) vdupq_n_s32((int32_t)((C) >> 1))
#define MULT_FIX(A, B) /* note: B is actualy scale>>1. See MAKE_HALF_CST */ \
// note: B is actualy scale>>1. See MAKE_HALF_CST
#define MULT_FIX(A, B) \
vreinterpretq_u32_s32(vqrdmulhq_s32(vreinterpretq_s32_u32((A)), (B)))
#define MULT_FIX_FLOOR(A, B) \
vreinterpretq_u32_s32(vqdmulhq_s32(vreinterpretq_s32_u32((A)), (B)))
#else
#error "MULT_FIX/WEBP_RESCALER_RFIX need some more work"
#endif
@ -135,8 +139,8 @@ static void RescalerExportRowShrink_NEON(WebPRescaler* const wrk) {
const uint32x4_t A1 = MULT_FIX(in1, yscale_half);
const uint32x4_t B0 = vqsubq_u32(in2, A0);
const uint32x4_t B1 = vqsubq_u32(in3, A1);
const uint32x4_t C0 = MULT_FIX(B0, fxy_scale_half);
const uint32x4_t C1 = MULT_FIX(B1, fxy_scale_half);
const uint32x4_t C0 = MULT_FIX_FLOOR(B0, fxy_scale_half);
const uint32x4_t C1 = MULT_FIX_FLOOR(B1, fxy_scale_half);
const uint16x4_t D0 = vmovn_u32(C0);
const uint16x4_t D1 = vmovn_u32(C1);
const uint8x8_t E = vmovn_u16(vcombine_u16(D0, D1));
@ -145,7 +149,7 @@ static void RescalerExportRowShrink_NEON(WebPRescaler* const wrk) {
}
for (; x_out < x_out_max; ++x_out) {
const uint32_t frac = (uint32_t)MULT_FIX_C(frow[x_out], yscale);
const int v = (int)MULT_FIX_C(irow[x_out] - frac, wrk->fxy_scale);
const int v = (int)MULT_FIX_FLOOR_C(irow[x_out] - frac, fxy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
irow[x_out] = frac; // new fractional start
@ -170,6 +174,12 @@ static void RescalerExportRowShrink_NEON(WebPRescaler* const wrk) {
}
}
#undef MULT_FIX_FLOOR_C
#undef MULT_FIX_C
#undef MULT_FIX_FLOOR
#undef MULT_FIX
#undef ROUNDER
//------------------------------------------------------------------------------
extern void WebPRescalerDspInitNEON(void);

35
src/dsp/rescaler_sse2.c
View File

@ -25,6 +25,7 @@
#define ROUNDER (WEBP_RESCALER_ONE >> 1)
#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
#define MULT_FIX_FLOOR(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
// input: 8 bytes ABCDEFGH -> output: A0E0B0F0C0G0D0H0
static void LoadTwoPixels_SSE2(const uint8_t* const src, __m128i* out) {
@ -224,6 +225,35 @@ static WEBP_INLINE void ProcessRow_SSE2(const __m128i* const A0,
_mm_storel_epi64((__m128i*)dst, G);
}
static WEBP_INLINE void ProcessRow_Floor_SSE2(const __m128i* const A0,
const __m128i* const A1,
const __m128i* const A2,
const __m128i* const A3,
const __m128i* const mult,
uint8_t* const dst) {
const __m128i mask = _mm_set_epi32(0xffffffffu, 0, 0xffffffffu, 0);
const __m128i B0 = _mm_mul_epu32(*A0, *mult);
const __m128i B1 = _mm_mul_epu32(*A1, *mult);
const __m128i B2 = _mm_mul_epu32(*A2, *mult);
const __m128i B3 = _mm_mul_epu32(*A3, *mult);
const __m128i D0 = _mm_srli_epi64(B0, WEBP_RESCALER_RFIX);
const __m128i D1 = _mm_srli_epi64(B1, WEBP_RESCALER_RFIX);
#if (WEBP_RESCALER_RFIX < 32)
const __m128i D2 =
_mm_and_si128(_mm_slli_epi64(B2, 32 - WEBP_RESCALER_RFIX), mask);
const __m128i D3 =
_mm_and_si128(_mm_slli_epi64(B3, 32 - WEBP_RESCALER_RFIX), mask);
#else
const __m128i D2 = _mm_and_si128(B2, mask);
const __m128i D3 = _mm_and_si128(B3, mask);
#endif
const __m128i E0 = _mm_or_si128(D0, D2);
const __m128i E1 = _mm_or_si128(D1, D3);
const __m128i F = _mm_packs_epi32(E0, E1);
const __m128i G = _mm_packus_epi16(F, F);
_mm_storel_epi64((__m128i*)dst, G);
}
static void RescalerExportRowExpand_SSE2(WebPRescaler* const wrk) {
int x_out;
uint8_t* const dst = wrk->dst;
@ -322,12 +352,12 @@ static void RescalerExportRowShrink_SSE2(WebPRescaler* const wrk) {
const __m128i G1 = _mm_or_si128(D1, F3);
_mm_storeu_si128((__m128i*)(irow + x_out + 0), G0);
_mm_storeu_si128((__m128i*)(irow + x_out + 4), G1);
ProcessRow_SSE2(&E0, &E1, &E2, &E3, &mult_xy, dst + x_out);
ProcessRow_Floor_SSE2(&E0, &E1, &E2, &E3, &mult_xy, dst + x_out);
}
}
for (; x_out < x_out_max; ++x_out) {
const uint32_t frac = (int)MULT_FIX(frow[x_out], yscale);
const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale);
const int v = (int)MULT_FIX_FLOOR(irow[x_out] - frac, wrk->fxy_scale);
assert(v >= 0 && v <= 255);
dst[x_out] = v;
irow[x_out] = frac; // new fractional start
@ -352,6 +382,7 @@ static void RescalerExportRowShrink_SSE2(WebPRescaler* const wrk) {
}
}
#undef MULT_FIX_FLOOR
#undef MULT_FIX
#undef ROUNDER