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Simplify forward-WHT + SSE2 version

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no precision loss observed
speed is not really faster (0.5% at max), as forward-WHT isn't called often.

also: replaced a "int << 3" (undefined by C-spec) by a "int * 8"
( supersedes https://gerrit.chromium.org/gerrit/#/c/48739/ )

Change-Id: I2d980ec2f20f4ff6be5636105ff4f1c70ffde401
(cherry picked from commit 9c4ce971a8)
This commit is contained in:
skal
2013-04-26 08:55:31 +02:00
committed by James Zern
parent f32097e0df
commit 38cc011408
3 changed files with 58 additions and 47 deletions
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29
src/dsp/enc.c
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@ -144,9 +144,9 @@ static void FTransform(const uint8_t* src, const uint8_t* ref, int16_t* out) {
const int a1 = (d1 + d2);
const int a2 = (d1 - d2);
const int a3 = (d0 - d3);
tmp[0 + i * 4] = (a0 + a1) << 3; // 14b [-8160,8160]
tmp[0 + i * 4] = (a0 + a1) * 8; // 14b [-8160,8160]
tmp[1 + i * 4] = (a2 * 2217 + a3 * 5352 + 1812) >> 9; // [-7536,7542]
tmp[2 + i * 4] = (a0 - a1) << 3;
tmp[2 + i * 4] = (a0 - a1) * 8;
tmp[3 + i * 4] = (a3 * 2217 - a2 * 5352 + 937) >> 9;
}
for (i = 0; i < 4; ++i) {
@ -189,31 +189,32 @@ static void ITransformWHT(const int16_t* in, int16_t* out) {
}
static void FTransformWHT(const int16_t* in, int16_t* out) {
int tmp[16];
// input is 12b signed
int16_t tmp[16];
int i;
for (i = 0; i < 4; ++i, in += 64) {
const int a0 = (in[0 * 16] + in[2 * 16]) << 2;
const int a1 = (in[1 * 16] + in[3 * 16]) << 2;
const int a2 = (in[1 * 16] - in[3 * 16]) << 2;
const int a3 = (in[0 * 16] - in[2 * 16]) << 2;
tmp[0 + i * 4] = (a0 + a1) + (a0 != 0);
const int a0 = (in[0 * 16] + in[2 * 16]); // 13b
const int a1 = (in[1 * 16] + in[3 * 16]);
const int a2 = (in[1 * 16] - in[3 * 16]);
const int a3 = (in[0 * 16] - in[2 * 16]);
tmp[0 + i * 4] = a0 + a1; // 14b
tmp[1 + i * 4] = a3 + a2;
tmp[2 + i * 4] = a3 - a2;
tmp[3 + i * 4] = a0 - a1;
}
for (i = 0; i < 4; ++i) {
const int a0 = (tmp[0 + i] + tmp[8 + i]);
const int a0 = (tmp[0 + i] + tmp[8 + i]); // 15b
const int a1 = (tmp[4 + i] + tmp[12+ i]);
const int a2 = (tmp[4 + i] - tmp[12+ i]);
const int a3 = (tmp[0 + i] - tmp[8 + i]);
const int b0 = a0 + a1;
const int b0 = a0 + a1; // 16b
const int b1 = a3 + a2;
const int b2 = a3 - a2;
const int b3 = a0 - a1;
out[ 0 + i] = (b0 + (b0 > 0) + 3) >> 3;
out[ 4 + i] = (b1 + (b1 > 0) + 3) >> 3;
out[ 8 + i] = (b2 + (b2 > 0) + 3) >> 3;
out[12 + i] = (b3 + (b3 > 0) + 3) >> 3;
out[ 0 + i] = b0 >> 1; // 15b
out[ 4 + i] = b1 >> 1;
out[ 8 + i] = b2 >> 1;
out[12 + i] = b3 >> 1;
}
}