diff options
| -rw-r--r-- | depends/packages/qt.mk | 2 | ||||
| -rw-r--r-- | depends/patches/qt/fix_qpainter_non_determinism.patch | 63 |
2 files changed, 65 insertions, 0 deletions
diff --git a/depends/packages/qt.mk b/depends/packages/qt.mk index 083bc68d66..2a9e066510 100644 --- a/depends/packages/qt.mk +++ b/depends/packages/qt.mk @@ -12,6 +12,7 @@ $(package)_patches=fix_qt_pkgconfig.patch mac-qmake.conf fix_configure_mac.patch $(package)_patches+= fix_rcc_determinism.patch fix_riscv64_arch.patch xkb-default.patch no-xlib.patch $(package)_patches+= fix_android_qmake_conf.patch fix_android_jni_static.patch dont_hardcode_pwd.patch $(package)_patches+= freetype_back_compat.patch drop_lrelease_dependency.patch fix_powerpc_libpng.patch +$(package)_patches+= fix_qpainter_non_determinism.patch # Update OSX_QT_TRANSLATIONS when this is updated $(package)_qttranslations_file_name=qttranslations-$($(package)_suffix) @@ -195,6 +196,7 @@ endef define $(package)_preprocess_cmds patch -p1 -i $($(package)_patch_dir)/freetype_back_compat.patch && \ patch -p1 -i $($(package)_patch_dir)/fix_powerpc_libpng.patch && \ + patch -p1 -i $($(package)_patch_dir)/fix_qpainter_non_determinism.patch &&\ sed -i.old "s|updateqm.commands = \$$$$\$$$$LRELEASE|updateqm.commands = $($(package)_extract_dir)/qttools/bin/lrelease|" qttranslations/translations/translations.pro && \ patch -p1 -i $($(package)_patch_dir)/drop_lrelease_dependency.patch && \ patch -p1 -i $($(package)_patch_dir)/dont_hardcode_pwd.patch &&\ diff --git a/depends/patches/qt/fix_qpainter_non_determinism.patch b/depends/patches/qt/fix_qpainter_non_determinism.patch new file mode 100644 index 0000000000..3cfcc22f03 --- /dev/null +++ b/depends/patches/qt/fix_qpainter_non_determinism.patch @@ -0,0 +1,63 @@ +commit 2a8f7dc6ddfc414a66491522501c1574a1343ee1 +Author: Andrew Chow <achow101-github@achow101.com> +Date: Sat Nov 21 01:11:04 2020 -0500 + + build: Fix determinism issue when building with Clang 8 + + When building Qt with LLVM/Clang 8 under -O3 (the default), we run into + a determinism issue in `qt_interset_spans`. The issue has been fixed for + LLVM/Clang 9, see + https://github.com/llvm/llvm-project/commit/db101864bdc938deb1d63fe4f7da761bd38e5cae + and https://reviews.llvm.org/D64601, however this fix was not backported + to 8.x. Once LLVM/Clang 9 is used, this patch can be dropped. + + The particular issue appears to be an optimization done by -O3 which + adds a temporary variable for `spans->y` in `qt_intersect_spans`. When + it does this, sometimes it chooses to use a 32-bit movs instruction + (movswl), and other times it chooses a 64-bit movs instruction (movswq). + By patching `qt_intersect_spans` to always make a temporary variable for + `spans->y`, we are able to sidestep this problem. + +diff --git a/qtbase/src/gui/painting/qpaintengine_raster.cpp b/qtbase/src/gui/painting/qpaintengine_raster.cpp +index 92ab6e8375..f018009e0b 100644 +--- a/qtbase/src/gui/painting/qpaintengine_raster.cpp ++++ b/qtbase/src/gui/painting/qpaintengine_raster.cpp +@@ -3971,22 +3971,23 @@ static const QSpan *qt_intersect_spans(const QClipData *clip, int *currentClip, + const QSpan *clipEnd = clip->m_spans + clip->count; + + while (available && spans < end ) { ++ const short spans_y = spans->y; + if (clipSpans >= clipEnd) { + spans = end; + break; + } +- if (clipSpans->y > spans->y) { ++ if (clipSpans->y > spans_y) { + ++spans; + continue; + } +- if (spans->y != clipSpans->y) { +- if (spans->y < clip->count && clip->m_clipLines[spans->y].spans) +- clipSpans = clip->m_clipLines[spans->y].spans; ++ if (spans_y != clipSpans->y) { ++ if (spans_y < clip->count && clip->m_clipLines[spans_y].spans) ++ clipSpans = clip->m_clipLines[spans_y].spans; + else + ++clipSpans; + continue; + } +- Q_ASSERT(spans->y == clipSpans->y); ++ Q_ASSERT(spans_y == clipSpans->y); + + int sx1 = spans->x; + int sx2 = sx1 + spans->len; +@@ -4005,7 +4006,7 @@ static const QSpan *qt_intersect_spans(const QClipData *clip, int *currentClip, + if (len) { + out->x = qMax(sx1, cx1); + out->len = qMin(sx2, cx2) - out->x; +- out->y = spans->y; ++ out->y = spans_y; + out->coverage = qt_div_255(spans->coverage * clipSpans->coverage); + ++out; + --available; + |