Merge "Merge remote-tracking branch 'origin/5.6' into 5.7" into refs/staging/5.7

4 files changed, 54 insertions, 10 deletions

diff --git a/src/corelib/tools/qhash.cpp b/src/corelib/tools/qhash.cpp
index 1001f2a06c..8ab98bd509 100644
--- a/src/corelib/tools/qhash.cpp
+++ b/src/corelib/tools/qhash.cpp
@@ -113,24 +113,24 @@ static uint crc32(const Char *ptr, size_t len, uint h)
 
     p += 8;
     for ( ; p <= e; p += 8)
-        h2 = _mm_crc32_u64(h2, *reinterpret_cast<const qlonglong *>(p - 8));
+        h2 = _mm_crc32_u64(h2, qUnalignedLoad<qlonglong>(p - 8));
     h = h2;
     p -= 8;
 
     len = e - p;
     if (len & 4) {
-        h = _mm_crc32_u32(h, *reinterpret_cast<const uint *>(p));
+        h = _mm_crc32_u32(h, qUnalignedLoad<uint>(p));
         p += 4;
     }
 #  else
     p += 4;
     for ( ; p <= e; p += 4)
-        h = _mm_crc32_u32(h, *reinterpret_cast<const uint *>(p - 4));
+        h = _mm_crc32_u32(h, qUnalignedLoad<uint>(p - 4));
     p -= 4;
     len = e - p;
 #  endif
     if (len & 2) {
-        h = _mm_crc32_u16(h, *reinterpret_cast<const ushort *>(p));
+        h = _mm_crc32_u16(h, qUnalignedLoad<ushort>(p));
         p += 2;
     }
     if (sizeof(Char) == 1 && len & 1)
diff --git a/src/corelib/tools/qsimd.cpp b/src/corelib/tools/qsimd.cpp
index 5bce42fd5a..9037442d9d 100644
--- a/src/corelib/tools/qsimd.cpp
+++ b/src/corelib/tools/qsimd.cpp
@@ -747,4 +747,26 @@ void qDumpCPUFeatures()
     puts("");
 }
 
+/*!
+    \internal
+    \fn T qUnalignedLoad(const void *ptr)
+    \since 5.6.1
+
+    Loads a \c{T} from address \a ptr, which may be misaligned.
+
+    Use of this function avoid the undefined behavior that the C++ standard
+    otherwise attributes to unaligned loads.
+*/
+
+/*!
+    \internal
+    \fn void qUnalignedStore(void *ptr, T t)
+    \since 5.6.1
+
+    Stores \a t to address \a ptr, which may be misaligned.
+
+    Use of this function avoid the undefined behavior that the C++ standard
+    otherwise attributes to unaligned stores.
+*/
+
 QT_END_NAMESPACE
diff --git a/src/corelib/tools/qsimd_p.h b/src/corelib/tools/qsimd_p.h
index 02439a2a9c..1a795a670d 100644
--- a/src/corelib/tools/qsimd_p.h
+++ b/src/corelib/tools/qsimd_p.h
@@ -521,6 +521,32 @@ unsigned _bit_scan_forward(unsigned val)
 #define ALIGNMENT_PROLOGUE_16BYTES(ptr, i, length) \
     for (; i < static_cast<int>(qMin(static_cast<quintptr>(length), ((4 - ((reinterpret_cast<quintptr>(ptr) >> 2) & 0x3)) & 0x3))); ++i)
 
+template <typename T>
+Q_ALWAYS_INLINE
+T qUnalignedLoad(const void *ptr) Q_DECL_NOTHROW
+{
+    T result;
+#if QT_HAS_BUILTIN(__builtin_memcpy)
+    __builtin_memcpy
+#else
+    memcpy
+#endif
+    /*memcpy*/(&result, ptr, sizeof result);
+    return result;
+}
+
+template <typename T>
+Q_ALWAYS_INLINE
+void qUnalignedStore(void *ptr, T t) Q_DECL_NOTHROW
+{
+#if QT_HAS_BUILTIN(__builtin_memcpy)
+    __builtin_memcpy
+#else
+    memcpy
+#endif
+    /*memcpy*/(ptr, &t, sizeof t);
+}
+
 QT_END_NAMESPACE
 
 #endif // QSIMD_P_H
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 943d8efe1d..c7cd1a7751 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -584,7 +584,7 @@ static int ucstrncmp(const QChar *a, const uchar *c, int l)
     // we'll read uc[offset..offset+7] (16 bytes) and c[offset..offset+7] (8 bytes)
     if (uc + offset + 7 < e) {
         // same, but we're using an 8-byte load
-        __m128i chunk = _mm_cvtsi64_si128(*(const long long *)(c + offset));
+        __m128i chunk = _mm_cvtsi64_si128(qUnalignedLoad<long long>(c + offset));
         __m128i secondHalf = _mm_unpacklo_epi8(chunk, nullmask);
 
         __m128i ucdata = _mm_loadu_si128((const __m128i*)(uc + offset));
@@ -6177,11 +6177,7 @@ QString QString::vasprintf(const char *cformat, va_list ap)
             }
             case 'p': {
                 void *arg = va_arg(ap, void*);
-#ifdef Q_OS_WIN64
-                quint64 i = reinterpret_cast<quint64>(arg);
-#else
-                quint64 i = reinterpret_cast<unsigned long>(arg);
-#endif
+                const quint64 i = reinterpret_cast<quintptr>(arg);
                 flags |= QLocaleData::Alternate;
                 subst = QLocaleData::c()->unsLongLongToString(i, precision, 16, width, flags);
                 ++c;