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~2% faster predictor #12 in NEON.

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Change-Id: I6772bb865d0f72720a65561eb55028e538df236d
This commit is contained in:
Pascal Massimino 2016-12-05 17:28:14 +01:00
parent 906c3b6392
commit 58a1f124c2
1 changed files with 30 additions and 17 deletions
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47
src/dsp/lossless_neon.c
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@ -351,28 +351,41 @@ static void PredictorAdd11_NEON(const uint32_t* in, const uint32_t* upper,
}
// Predictor12: ClampedAddSubtractFull.
#define DO_PRED12(DIFF, LANE, OUT) do { \
const uint8x8_t pred = \
vqmovun_s16(vaddq_s16(vreinterpretq_s16_u16(left), (DIFF))); \
const uint8x8_t res = \
vadd_u8(pred, (OUT <= 1) ? vget_low_u8(src) : vget_high_u8(src)); \
vst1_lane_u32(&out[i + (OUT)], vreinterpret_u32_u8(res), (LANE)); \
/* rotate in the left predictor for next iteration */ \
left = (LANE == 0) ? vextq_u16(zero, vmovl_u8(res), 4) \
: vextq_u16(vmovl_u8(res), zero, 4); \
} while (0)
static void PredictorAdd12_NEON(const uint32_t* in, const uint32_t* upper,
int num_pixels, uint32_t* out) {
int i, j;
// +4 to not read outside of memory.
for (i = 0; i + 4 <= num_pixels; i += 2) {
uint8x8_t src = LOAD_U32P_AS_U8(&in[i]);
const uint8x8_t TL = LOAD_U32P_AS_U8(&upper[i - 1]);
const uint8x8_t T = LOAD_U32P_AS_U8(&upper[i]);
int16x8_t diff = vreinterpretq_s16_u16(vsubl_u8(T, TL));
for (j = 0; j < 2; ++j) {
const uint8x8_t L8 = LOAD_U32_AS_U8(out[i + j - 1]);
const int16x8_t L = vreinterpretq_s16_u16(vmovl_u8(L8));
const int16x8_t sum = vaddq_s16(L, diff);
const uint8x8_t res = vadd_u8(vqmovun_s16(sum), src);
out[i + j] = vget_lane_u32(vreinterpret_u32_u8(res), 0);
// Shift the pre-computed value for the next iteration.
diff = vextq_s16(diff, diff, 4);
src = vext_u8(src, src, 4);
}
int i;
const uint16x8_t zero = vdupq_n_u16(0);
uint16x8_t left = vmovl_u8(LOAD_U32_AS_U8(out[-1]));
for (i = 0; i + 4 <= num_pixels; i += 4) {
// load four pixels of source
const uint8x16_t src = LOADQ_U32P_AS_U8(&in[i]);
// precompute the difference T - TL once for all, stored as s16
const uint8x16_t TL = LOADQ_U32P_AS_U8(&upper[i - 1]);
const uint8x16_t T = LOADQ_U32P_AS_U8(&upper[i]);
const int16x8_t diff_lo =
vreinterpretq_s16_u16(vsubl_u8(vget_low_u8(T), vget_low_u8(TL)));
const int16x8_t diff_hi =
vreinterpretq_s16_u16(vsubl_u8(vget_high_u8(T), vget_high_u8(TL)));
// loop over the four reconstructed pixels
DO_PRED12(diff_lo, 0, 0);
DO_PRED12(diff_lo, 1, 1);
DO_PRED12(diff_hi, 0, 2);
DO_PRED12(diff_hi, 1, 3);
}
VP8LPredictorsAdd_C[12](in + i, upper + i, num_pixels - i, out + i);
}
#undef DO_PRED12
#undef LOAD_U32_AS_U8
#undef LOAD_U32P_AS_U8