From a18370cbed705487491901f5c6f7a1a60f303373 Mon Sep 17 00:00:00 2001 From: Allan Sandfeld Jensen Date: Thu, 19 Apr 2018 17:37:23 +0200 Subject: Optimize intermediate_adder_avx2 Use 16-bit multiplication as it is twice as fast as 32-bit multiplication. Change-Id: I64b529eaaed4ce2c59c64a0120e93cd132724156 Reviewed-by: Thiago Macieira --- src/gui/painting/qdrawhelper_avx2.cpp | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'src') diff --git a/src/gui/painting/qdrawhelper_avx2.cpp b/src/gui/painting/qdrawhelper_avx2.cpp index 1c225b4568..ec6643deed 100644 --- a/src/gui/painting/qdrawhelper_avx2.cpp +++ b/src/gui/painting/qdrawhelper_avx2.cpp @@ -667,6 +667,8 @@ void QT_FASTCALL intermediate_adder_avx2(uint *b, uint *end, const IntermediateB const __m128i v_fdx = _mm_set1_epi32(fdx * 4); const __m128i v_blend = _mm_set1_epi32(0x00800080); + const __m128i vdx_shuffle = _mm_set_epi8(char(0x80), 13, char(0x80), 13, char(0x80), 9, char(0x80), 9, + char(0x80), 5, char(0x80), 5, char(0x80), 1, char(0x80), 1); __m128i v_fx = _mm_setr_epi32(fx, fx + fdx, fx + fdx + fdx, fx + fdx + fdx + fdx); while (b < end - 3) { @@ -674,14 +676,13 @@ void QT_FASTCALL intermediate_adder_avx2(uint *b, uint *end, const IntermediateB __m256i vrb = _mm256_i32gather_epi64((const long long *)intermediate.buffer_rb, offset, 4); __m256i vag = _mm256_i32gather_epi64((const long long *)intermediate.buffer_ag, offset, 4); - __m128i vdx = _mm_and_si128(v_fx, _mm_set1_epi32(0x0000ffff)); - vdx = _mm_srli_epi16(vdx, 8); - __m128i vidx = _mm_sub_epi32(_mm_set1_epi32(256), vdx); + __m128i vdx = _mm_shuffle_epi8(v_fx, vdx_shuffle); + __m128i vidx = _mm_sub_epi16(_mm_set1_epi16(256), vdx); __m256i vmulx = _mm256_castsi128_si256(_mm_unpacklo_epi32(vidx, vdx)); vmulx = _mm256_inserti128_si256(vmulx, _mm_unpackhi_epi32(vidx, vdx), 1); - vrb = _mm256_mullo_epi32(vrb, vmulx); - vag = _mm256_mullo_epi32(vag, vmulx); + vrb = _mm256_mullo_epi16(vrb, vmulx); + vag = _mm256_mullo_epi16(vag, vmulx); __m256i vrbag = _mm256_hadd_epi32(vrb, vag); vrbag = _mm256_permute4x64_epi64(vrbag, _MM_SHUFFLE(3, 1, 2, 0)); @@ -693,9 +694,9 @@ void QT_FASTCALL intermediate_adder_avx2(uint *b, uint *end, const IntermediateB _mm_storeu_si128((__m128i*)b, _mm_blendv_epi8(ag, rb, v_blend)); b += 4; - fx += 4 * fdx; v_fx = _mm_add_epi32(v_fx, v_fdx); } + fx = _mm_cvtsi128_si32(v_fx); while (b < end) { const int x = (fx >> 16); -- cgit v1.2.3