diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp
index bd853ad934..5e71972c2e 100644
--- a/src/gui/painting/qdrawhelper.cpp
+++ b/src/gui/painting/qdrawhelper.cpp
@@ -1313,7 +1313,7 @@ static void QT_FASTCALL destStore(QRasterBuffer *rasterBuffer, int x, int y, con
 static void QT_FASTCALL convertFromRgb64(uint *dest, const QRgba64 *src, int length)
 {
     for (int i = 0; i < length; ++i) {
-        dest[i] = src[i].toArgb32();
+        dest[i] = toArgb32(src[i]);
     }
 }
 
@@ -1404,7 +1404,7 @@ static void QT_FASTCALL destStore64ARGB32(QRasterBuffer *rasterBuffer, int x, in
 {
     uint *dest = (uint*)rasterBuffer->scanLine(y) + x;
     for (int i = 0; i < length; ++i) {
-        dest[i] = buffer[i].unpremultiplied().toArgb32();
+        dest[i] = toArgb32(buffer[i].unpremultiplied());
     }
 }
 
@@ -1412,7 +1412,7 @@ static void QT_FASTCALL destStore64RGBA8888(QRasterBuffer *rasterBuffer, int x,
 {
     uint *dest = (uint*)rasterBuffer->scanLine(y) + x;
     for (int i = 0; i < length; ++i) {
-        dest[i] = ARGB2RGBA(buffer[i].unpremultiplied().toArgb32());
+        dest[i] = toRgba8888(buffer[i].unpremultiplied());
     }
 }
 
diff --git a/src/gui/painting/qrgba64_p.h b/src/gui/painting/qrgba64_p.h
index 0dadc038fa..08e73942df 100644
--- a/src/gui/painting/qrgba64_p.h
+++ b/src/gui/painting/qrgba64_p.h
@@ -185,6 +185,55 @@ inline QRgba64 addWithSaturation(QRgba64 a, QRgba64 b)
                                qMin(a.alpha() + b.alpha(), 65535));
 }
 
+#if defined __SSE2__
+Q_ALWAYS_INLINE uint toArgb32(__m128i v)
+{
+    v = _mm_unpacklo_epi16(v, _mm_setzero_si128());
+    v = _mm_add_epi32(v, _mm_set1_epi32(128));
+    v = _mm_sub_epi32(v, _mm_srli_epi32(v, 8));
+    v = _mm_srli_epi32(v, 8);
+    v = _mm_packs_epi32(v, v);
+    v = _mm_packus_epi16(v, v);
+    return _mm_cvtsi128_si32(v);
+}
+#elif defined __ARM_NEON__
+Q_ALWAYS_INLINE uint toArgb32(uint16x4_t v)
+{
+    v = vsub_u16(v, vrshr_n_u16(v, 8));
+    v = vrshr_n_u16(v, 8);
+    uint8x8_t v8 = vmovn_u16(vcombine_u16(v, v));
+    return vget_lane_u32(vreinterpret_u32_u8(v8), 0);
+}
+#endif
+
+inline uint toArgb32(QRgba64 rgba64)
+{
+#if defined __SSE2__
+    __m128i v = _mm_loadl_epi64((const __m128i *)&rgba64);
+    v = _mm_shufflelo_epi16(v, _MM_SHUFFLE(3, 0, 1, 2));
+    return toArgb32(v);
+#elif defined __ARM_NEON__
+    uint16x4_t v = vreinterpret_u16_u64(vld1_u64(reinterpret_cast<const uint64_t *>(&rgba64)));
+    v = vext_u16(v, v, 1);
+    return toArgb32(v);
+#else
+    return rgba64.toArgb32();
+#endif
+}
+
+inline uint toRgba8888(QRgba64 rgba64)
+{
+#if defined __SSE2__
+    __m128i v = _mm_loadl_epi64((const __m128i *)&rgba64);
+    return toArgb32(v);
+#elif defined __ARM_NEON__
+    uint16x4_t v = vreinterpret_u16_u64(vld1_u64(reinterpret_cast<const uint64_t *>(&rgba64)));
+    return toArgb32(v);
+#else
+    return ARGB2RGBA(toArgb32(rgba64));
+#endif
+}
+
 #if defined(__SSE2__)
 Q_ALWAYS_INLINE __m128i addWithSaturation(__m128i a, __m128i b)
 {