Remove runtime detection of SSE2

If the compiler supports SSE2, we'll use our SSE2-optimised code
unconditionally. Runtime detection is left for SSSE3 code.

The SSE2 codebase is big and thus a timebomb if an inline function
gets leaked out and run without runtime check. In reality, it's
extremely unlikely people running CPUs without SSE2 support are
running Qt 5 at this moment (they're either too old or too new,
e.g. Intel Quark).

The SSSE3 codebase is a lot more manageable.

Task-number: QTBUG-30440
Change-Id: I3e586e4434e820365d5316b650ee3061d0acf767
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

6 files changed, 72 insertions, 85 deletions

diff --git a/src/gui/image/image.pri b/src/gui/image/image.pri
index 1877f60bfd..ad860ef2db 100644
--- a/src/gui/image/image.pri
+++ b/src/gui/image/image.pri
@@ -79,5 +79,7 @@ contains(QT_CONFIG, gif):include($$PWD/qgifhandler.pri)
 
 # SIMD
 NEON_SOURCES += image/qimage_neon.cpp
-SSE2_SOURCES += image/qimage_sse2.cpp
-SSSE3_SOURCES += image/qimage_ssse3.cpp
+contains(QT_CPU_FEATURES.$$QT_ARCH, sse2) {
+    SOURCES += image/qimage_sse2.cpp
+    SSSE3_SOURCES += image/qimage_ssse3.cpp
+}
diff --git a/src/gui/image/qimage_conversions.cpp b/src/gui/image/qimage_conversions.cpp
index c009dcb9e1..317ba45dac 100644
--- a/src/gui/image/qimage_conversions.cpp
+++ b/src/gui/image/qimage_conversions.cpp
@@ -162,6 +162,9 @@ static void convert_ARGB_to_ARGB_PM(QImageData *dest, const QImageData *src, Qt:
     }
 }
 
+extern bool convert_ARGB_to_ARGB_PM_inplace_sse2(QImageData *data, Qt::ImageConversionFlags);
+
+#ifndef __SSE2__
 static bool convert_ARGB_to_ARGB_PM_inplace(QImageData *data, Qt::ImageConversionFlags)
 {
     Q_ASSERT(data->format == QImage::Format_ARGB32);
@@ -180,6 +183,7 @@ static bool convert_ARGB_to_ARGB_PM_inplace(QImageData *data, Qt::ImageConversio
     data->format = QImage::Format_ARGB32_Premultiplied;
     return true;
 }
+#endif
 
 static void convert_ARGB_to_RGBx(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags)
 {
@@ -1986,7 +1990,11 @@ InPlace_Image_Converter qimage_inplace_converter_map[QImage::NImageFormats][QIma
         0,
         0,
         0,
+#ifdef __SSE2__
+        convert_ARGB_to_ARGB_PM_inplace_sse2,
+#else
         convert_ARGB_to_ARGB_PM_inplace,
+#endif
         0,
         0,
         0,
@@ -2115,21 +2123,14 @@ InPlace_Image_Converter qimage_inplace_converter_map[QImage::NImageFormats][QIma
 
 void qInitImageConversions()
 {
-#if defined(QT_COMPILER_SUPPORTS_SSE2)
-    if (qCpuHasFeature(SSE2)) {
-        extern bool convert_ARGB_to_ARGB_PM_inplace_sse2(QImageData *data, Qt::ImageConversionFlags);
-        qimage_inplace_converter_map[QImage::Format_ARGB32][QImage::Format_ARGB32_Premultiplied] = convert_ARGB_to_ARGB_PM_inplace_sse2;
-#ifdef QT_COMPILER_SUPPORTS_SSSE3
-        if (qCpuHasFeature(SSSE3)) {
-            extern void convert_RGB888_to_RGB32_ssse3(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags);
-            qimage_converter_map[QImage::Format_RGB888][QImage::Format_RGB32] = convert_RGB888_to_RGB32_ssse3;
-            qimage_converter_map[QImage::Format_RGB888][QImage::Format_ARGB32] = convert_RGB888_to_RGB32_ssse3;
-            qimage_converter_map[QImage::Format_RGB888][QImage::Format_ARGB32_Premultiplied] = convert_RGB888_to_RGB32_ssse3;
-        }
-#endif
-        return;
+#if defined(__SSE2__) && defined(QT_COMPILER_SUPPORTS_SSSE3)
+    if (qCpuHasFeature(SSSE3)) {
+        extern void convert_RGB888_to_RGB32_ssse3(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags);
+        qimage_converter_map[QImage::Format_RGB888][QImage::Format_RGB32] = convert_RGB888_to_RGB32_ssse3;
+        qimage_converter_map[QImage::Format_RGB888][QImage::Format_ARGB32] = convert_RGB888_to_RGB32_ssse3;
+        qimage_converter_map[QImage::Format_RGB888][QImage::Format_ARGB32_Premultiplied] = convert_RGB888_to_RGB32_ssse3;
     }
-#endif // SSE2
+#endif
 
 #ifdef QT_COMPILER_SUPPORTS_NEON
     if (qCpuHasFeature(NEON)) {
diff --git a/src/gui/painting/painting.pri b/src/gui/painting/painting.pri
index 17f80fd513..271848ae73 100644
--- a/src/gui/painting/painting.pri
+++ b/src/gui/painting/painting.pri
@@ -87,8 +87,10 @@ SOURCES += \
         painting/qpaintbuffer.cpp \
         painting/qpathsimplifier.cpp
 
-SSE2_SOURCES += painting/qdrawhelper_sse2.cpp
-SSSE3_SOURCES += painting/qdrawhelper_ssse3.cpp
+contains(QT_CPU_FEATURES.$$QT_ARCH, sse2) {
+    SOURCES += painting/qdrawhelper_sse2.cpp
+    SSSE3_SOURCES += painting/qdrawhelper_ssse3.cpp
+}
 IWMMXT_SOURCES += painting/qdrawhelper_iwmmxt.cpp
 
 !ios {
diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp
index cec829a509..ae6a5e01e5 100644
--- a/src/gui/painting/qdrawhelper.cpp
+++ b/src/gui/painting/qdrawhelper.cpp
@@ -6201,62 +6201,51 @@ void qInitDrawhelperAsm()
     CompositionFunctionSolid *functionForModeSolidAsm = 0;
 
     const uint features = qCpuFeatures();
-    if (false) {
-        Q_UNUSED(features);
-#ifdef QT_COMPILER_SUPPORTS_SSE2
-    } else if (features & SSE2) {
+    Q_UNUSED(features);
+#ifdef __SSE2__
         qt_memfill32 = qt_memfill32_sse2;
         qt_memfill16 = qt_memfill16_sse2;
-        qDrawHelper[QImage::Format_RGB32].bitmapBlit = qt_bitmapblit32_sse2;
-        qDrawHelper[QImage::Format_ARGB32].bitmapBlit = qt_bitmapblit32_sse2;
-        qDrawHelper[QImage::Format_ARGB32_Premultiplied].bitmapBlit = qt_bitmapblit32_sse2;
-        qDrawHelper[QImage::Format_RGB16].bitmapBlit = qt_bitmapblit16_sse2;
-        qDrawHelper[QImage::Format_RGBX8888].bitmapBlit = qt_bitmapblit32_sse2;
-        qDrawHelper[QImage::Format_RGBA8888].bitmapBlit = qt_bitmapblit32_sse2;
-        qDrawHelper[QImage::Format_RGBA8888_Premultiplied].bitmapBlit = qt_bitmapblit32_sse2;
-
-        extern void qt_scale_image_argb32_on_argb32_sse2(uchar *destPixels, int dbpl,
-                                                         const uchar *srcPixels, int sbpl,
-                                                         const QRectF &targetRect,
-                                                         const QRectF &sourceRect,
-                                                         const QRect &clip,
-                                                         int const_alpha);
-        qScaleFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_ARGB32_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
-        qScaleFunctions[QImage::Format_RGB32][QImage::Format_ARGB32_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
-#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
-        qScaleFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBA8888_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
-        qScaleFunctions[QImage::Format_RGBX8888][QImage::Format_RGBA8888_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
-#endif
-#endif
-    }
-
-#ifdef QT_COMPILER_SUPPORTS_SSE2
-    if (features & SSE2) {
-        extern void qt_blend_rgb32_on_rgb32_sse2(uchar *destPixels, int dbpl,
-                                                 const uchar *srcPixels, int sbpl,
-                                                 int w, int h,
-                                                 int const_alpha);
-        extern void qt_blend_argb32_on_argb32_sse2(uchar *destPixels, int dbpl,
-                                                   const uchar *srcPixels, int sbpl,
-                                                   int w, int h,
-                                                   int const_alpha);
-
-        qBlendFunctions[QImage::Format_RGB32][QImage::Format_RGB32] = qt_blend_rgb32_on_rgb32_sse2;
-        qBlendFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_RGB32] = qt_blend_rgb32_on_rgb32_sse2;
-        qBlendFunctions[QImage::Format_RGB32][QImage::Format_ARGB32_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
-        qBlendFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_ARGB32_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
-#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
-        qBlendFunctions[QImage::Format_RGBX8888][QImage::Format_RGBX8888] = qt_blend_rgb32_on_rgb32_sse2;
-        qBlendFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBX8888] = qt_blend_rgb32_on_rgb32_sse2;
-        qBlendFunctions[QImage::Format_RGBX8888][QImage::Format_RGBA8888_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
-        qBlendFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBA8888_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
-#endif
-
-        extern const uint * QT_FASTCALL qt_fetch_radial_gradient_sse2(uint *buffer, const Operator *op, const QSpanData *data,
-                                                                      int y, int x, int length);
-
-        qt_fetch_radial_gradient = qt_fetch_radial_gradient_sse2;
-    }
+    qDrawHelper[QImage::Format_RGB32].bitmapBlit = qt_bitmapblit32_sse2;
+    qDrawHelper[QImage::Format_ARGB32].bitmapBlit = qt_bitmapblit32_sse2;
+    qDrawHelper[QImage::Format_ARGB32_Premultiplied].bitmapBlit = qt_bitmapblit32_sse2;
+    qDrawHelper[QImage::Format_RGB16].bitmapBlit = qt_bitmapblit16_sse2;
+    qDrawHelper[QImage::Format_RGBX8888].bitmapBlit = qt_bitmapblit32_sse2;
+    qDrawHelper[QImage::Format_RGBA8888].bitmapBlit = qt_bitmapblit32_sse2;
+    qDrawHelper[QImage::Format_RGBA8888_Premultiplied].bitmapBlit = qt_bitmapblit32_sse2;
+
+    extern void qt_scale_image_argb32_on_argb32_sse2(uchar *destPixels, int dbpl,
+                                                     const uchar *srcPixels, int sbpl,
+                                                     const QRectF &targetRect,
+                                                     const QRectF &sourceRect,
+                                                     const QRect &clip,
+                                                     int const_alpha);
+    qScaleFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_ARGB32_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
+    qScaleFunctions[QImage::Format_RGB32][QImage::Format_ARGB32_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
+    qScaleFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBA8888_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
+    qScaleFunctions[QImage::Format_RGBX8888][QImage::Format_RGBA8888_Premultiplied] = qt_scale_image_argb32_on_argb32_sse2;
+
+    extern void qt_blend_rgb32_on_rgb32_sse2(uchar *destPixels, int dbpl,
+                                             const uchar *srcPixels, int sbpl,
+                                             int w, int h,
+                                             int const_alpha);
+    extern void qt_blend_argb32_on_argb32_sse2(uchar *destPixels, int dbpl,
+                                               const uchar *srcPixels, int sbpl,
+                                               int w, int h,
+                                               int const_alpha);
+
+    qBlendFunctions[QImage::Format_RGB32][QImage::Format_RGB32] = qt_blend_rgb32_on_rgb32_sse2;
+    qBlendFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_RGB32] = qt_blend_rgb32_on_rgb32_sse2;
+    qBlendFunctions[QImage::Format_RGB32][QImage::Format_ARGB32_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
+    qBlendFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_ARGB32_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
+    qBlendFunctions[QImage::Format_RGBX8888][QImage::Format_RGBX8888] = qt_blend_rgb32_on_rgb32_sse2;
+    qBlendFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBX8888] = qt_blend_rgb32_on_rgb32_sse2;
+    qBlendFunctions[QImage::Format_RGBX8888][QImage::Format_RGBA8888_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
+    qBlendFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBA8888_Premultiplied] = qt_blend_argb32_on_argb32_sse2;
+
+    extern const uint * QT_FASTCALL qt_fetch_radial_gradient_sse2(uint *buffer, const Operator *op, const QSpanData *data,
+                                                                  int y, int x, int length);
+
+    qt_fetch_radial_gradient = qt_fetch_radial_gradient_sse2;
 
 #ifdef QT_COMPILER_SUPPORTS_SSSE3
     if (features & SSSE3) {
@@ -6267,22 +6256,15 @@ void qInitDrawhelperAsm()
 
         qBlendFunctions[QImage::Format_RGB32][QImage::Format_ARGB32_Premultiplied] = qt_blend_argb32_on_argb32_ssse3;
         qBlendFunctions[QImage::Format_ARGB32_Premultiplied][QImage::Format_ARGB32_Premultiplied] = qt_blend_argb32_on_argb32_ssse3;
-#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
         qBlendFunctions[QImage::Format_RGBX8888][QImage::Format_RGBA8888_Premultiplied] = qt_blend_argb32_on_argb32_ssse3;
         qBlendFunctions[QImage::Format_RGBA8888_Premultiplied][QImage::Format_RGBA8888_Premultiplied] = qt_blend_argb32_on_argb32_ssse3;
-#endif
     }
 #endif // SSSE3
 
+    functionForModeAsm = qt_functionForMode_SSE2;
+    functionForModeSolidAsm = qt_functionForModeSolid_SSE2;
 #endif // SSE2
 
-#ifdef QT_COMPILER_SUPPORTS_SSE2
-    if (features & SSE2) {
-        functionForModeAsm = qt_functionForMode_SSE2;
-        functionForModeSolidAsm = qt_functionForModeSolid_SSE2;
-        }
-#endif
-
 #ifdef QT_COMPILER_SUPPORTS_IWMMXT
     if (features & IWMMXT) {
         functionForModeAsm = qt_functionForMode_IWMMXT;
diff --git a/src/gui/painting/qdrawhelper_x86_p.h b/src/gui/painting/qdrawhelper_x86_p.h
index 105eaae63a..4458d11903 100644
--- a/src/gui/painting/qdrawhelper_x86_p.h
+++ b/src/gui/painting/qdrawhelper_x86_p.h
@@ -57,7 +57,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_COMPILER_SUPPORTS_SSE2
+#ifdef __SSE2__
 void qt_memfill32_sse2(quint32 *dest, quint32 value, int count);
 void qt_memfill16_sse2(quint16 *dest, quint16 value, int count);
 void qt_bitmapblit32_sse2(QRasterBuffer *rasterBuffer, int x, int y,
@@ -77,7 +77,7 @@ void qt_blend_rgb32_on_rgb32_sse2(uchar *destPixels, int dbpl,
 
 extern CompositionFunction qt_functionForMode_SSE2[];
 extern CompositionFunctionSolid qt_functionForModeSolid_SSE2[];
-#endif // QT_COMPILER_SUPPORTS_SSE2
+#endif // __SSE2__
 
 #ifdef QT_COMPILER_SUPPORTS_IWMMXT
 void qt_blend_color_argb_iwmmxt(int count, const QSpan *spans, void *userData);
diff --git a/src/gui/painting/qdrawingprimitive_sse2_p.h b/src/gui/painting/qdrawingprimitive_sse2_p.h
index 0e0c06f56c..cdf68b932d 100644
--- a/src/gui/painting/qdrawingprimitive_sse2_p.h
+++ b/src/gui/painting/qdrawingprimitive_sse2_p.h
@@ -44,7 +44,7 @@
 
 #include <private/qsimd_p.h>
 
-#ifdef QT_COMPILER_SUPPORTS_SSE2
+#ifdef __SSE2__
 
 //
 //  W A R N I N G
@@ -242,6 +242,6 @@ QT_BEGIN_NAMESPACE
 
 QT_END_NAMESPACE
 
-#endif // QT_COMPILER_SUPPORTS_SSE2
+#endif // __SSE2__
 
 #endif // QDRAWINGPRIMITIVE_SSE2_P_H