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Copy C code to not have multiplication overflow

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Change-Id: I9375170ce1217921a334c5b93dc3e0084f976688
This commit is contained in:
Vincent Rabaud
2024-03-05 11:33:59 +01:00
parent 1fb9f3dcf1
commit 501d9274a7
12 changed files with 109 additions and 126 deletions
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17
src/dsp/dec_neon.c
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@ -1000,8 +1000,9 @@ static void HFilter8i_NEON(uint8_t* u, uint8_t* v, int stride,
// libwebp adds 1 << 16 to cospi8sqrt2minus1 (kC1). However, this causes the
// same issue with kC1 and vqdmulh that we work around by down shifting kC2
static const int16_t kC1 = 20091;
static const int16_t kC2 = 17734; // half of kC2, actually. See comment above.
static const int16_t kC1 = WEBP_TRANSFORM_AC3_C1;
static const int16_t kC2 =
WEBP_TRANSFORM_AC3_C2 / 2; // half of kC2, actually. See comment above.
#if defined(WEBP_USE_INTRINSICS)
static WEBP_INLINE void Transpose8x2_NEON(const int16x8_t in0,
@ -1255,15 +1256,12 @@ static void TransformWHT_NEON(const int16_t* in, int16_t* out) {
//------------------------------------------------------------------------------
#define MUL(a, b) (((a) * (b)) >> 16)
static void TransformAC3_NEON(const int16_t* in, uint8_t* dst) {
static const int kC1_full = 20091 + (1 << 16);
static const int kC2_full = 35468;
const int16x4_t A = vld1_dup_s16(in);
const int16x4_t c4 = vdup_n_s16(MUL(in[4], kC2_full));
const int16x4_t d4 = vdup_n_s16(MUL(in[4], kC1_full));
const int c1 = MUL(in[1], kC2_full);
const int d1 = MUL(in[1], kC1_full);
const int16x4_t c4 = vdup_n_s16(WEBP_TRANSFORM_AC3_MUL2(in[4]));
const int16x4_t d4 = vdup_n_s16(WEBP_TRANSFORM_AC3_MUL1(in[4]));
const int c1 = WEBP_TRANSFORM_AC3_MUL2(in[1]);
const int d1 = WEBP_TRANSFORM_AC3_MUL1(in[1]);
const uint64_t cd = (uint64_t)( d1 & 0xffff) << 0 |
(uint64_t)( c1 & 0xffff) << 16 |
(uint64_t)(-c1 & 0xffff) << 32 |
@ -1274,7 +1272,6 @@ static void TransformAC3_NEON(const int16_t* in, uint8_t* dst) {
const int16x8_t m2_m3 = vcombine_s16(vqsub_s16(B, c4), vqsub_s16(B, d4));
Add4x4_NEON(m0_m1, m2_m3, dst);
}
#undef MUL
//------------------------------------------------------------------------------
// 4x4