1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Avoid SSE2 punning

Browse Source 
It is technical UB, even if GCC promises to let it work, but it also
generates inefficient code.

Change-Id: I8f0cae3490d32287ecbaa16b1e9ace84223cda2a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 821aa1ff095ae66a89eb8725650dccac363f06ad)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
This commit is contained in:
Allan Sandfeld Jensen 2022-06-24 14:27:18 +02:00 committed by Qt Cherry-pick Bot
parent ad646f62fb
commit 2e37845cee
1 changed files with 6 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
src/gui/painting/qdrawhelper_sse2.cpp
View File

@ -571,13 +571,14 @@ void qt_scale_image_argb32_on_argb32_sse2(uchar *destPixels, int dbpl,
__m128i srcxVector = _mm_set_epi32(srcx, srcx + ix, srcx + ix + ix, srcx + ix + ix + ix);
for (; x<w - 3; x += 4) {
union Vect_buffer { __m128i vect; quint32 i[4]; };
Vect_buffer addr;
addr.vect = _mm_srli_epi32(srcxVector, 16);
for (; x < (w - 3); x += 4) {
const int idx0 = _mm_extract_epi16(srcxVector, 1);
const int idx1 = _mm_extract_epi16(srcxVector, 3);
const int idx2 = _mm_extract_epi16(srcxVector, 5);
const int idx3 = _mm_extract_epi16(srcxVector, 7);
srcxVector = _mm_add_epi32(srcxVector, ixVector);
const __m128i srcVector = _mm_set_epi32(src[addr.i[0]], src[addr.i[1]], src[addr.i[2]], src[addr.i[3]]);
const __m128i srcVector = _mm_set_epi32(src[idx0], src[idx1], src[idx2], src[idx3]);
BLEND_SOURCE_OVER_ARGB32_SSE2_helper(dst, srcVector, nullVector, half, one, colorMask, alphaMask);
}