libwebp/src/dsp/lossless_enc_sse41.c
Pascal Massimino fc6c75a2a2 SSE2: 53% faster TransformColor[Inverse]
Changed the code (again) to process 4 pixels at a time. Loop is more
involved, but overall it's faster.

Removed the SSE4.1 implementation which is now slower than SSE2.

Change-Id: I7734e371033ad8929ace7f7e1373ba930d9bb5f1
2015-06-23 14:52:01 -07:00

52 lines
1.7 KiB
C

// Copyright 2015 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// SSE4.1 variant of methods for lossless encoder
//
// Author: Skal (pascal.massimino@gmail.com)
#include "./dsp.h"
#if defined(WEBP_USE_SSE41)
#include <assert.h>
#include <smmintrin.h>
#include "./lossless.h"
//------------------------------------------------------------------------------
// Subtract-Green Transform
static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixels) {
int i;
const __m128i kCstShuffle = _mm_set_epi8(-1, 13, -1, 13, -1, 9, -1, 9,
-1, 5, -1, 5, -1, 1, -1, 1);
for (i = 0; i + 4 <= num_pixels; i += 4) {
const __m128i in = _mm_loadu_si128((__m128i*)&argb_data[i]);
const __m128i in_0g0g = _mm_shuffle_epi8(in, kCstShuffle);
const __m128i out = _mm_sub_epi8(in, in_0g0g);
_mm_storeu_si128((__m128i*)&argb_data[i], out);
}
// fallthrough and finish off with plain-C
VP8LSubtractGreenFromBlueAndRed_C(argb_data + i, num_pixels - i);
}
//------------------------------------------------------------------------------
// Entry point
extern void VP8LEncDspInitSSE41(void);
WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitSSE41(void) {
VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed;
}
#else // !WEBP_USE_SSE41
WEBP_DSP_INIT_STUB(VP8LEncDspInitSSE41)
#endif // WEBP_USE_SSE41