Replace qUnaligned{Load,Store} with the existing q{To,From}Unaligned

Move the Q_ALWAYS_INLINE and forcing of __builtin_memcpy to the existing
functions.

Change-Id: Icaa7fb2a490246bda156ffff143c137e520eea79
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

src/corelib/global/qendian.h

@@ -42,6 +42,11 @@
 
 QT_BEGIN_NAMESPACE
 
+#ifdef __has_builtin
+#  define QT_HAS_BUILTIN(x)     __has_builtin(x)
+#else
+#  define QT_HAS_BUILTIN(x)     0
+#endif
 
 /*
  * ENDIAN FUNCTIONS
@@ -64,18 +69,29 @@ template <typename T> inline void qbswap(const T src, uchar *dest)
 
 // Used to implement a type-safe and alignment-safe copy operation
 // If you want to avoid the memcpy, you must write specializations for these functions
-template <typename T> inline void qToUnaligned(const T src, uchar *dest)
+template <typename T> Q_ALWAYS_INLINE void qToUnaligned(const T src, uchar *dest)
 {
     // Using sizeof(T) inside memcpy function produces internal compiler error with
     // MSVC2008/ARM in tst_endian -> use extra indirection to resolve size of T.
     const size_t size = sizeof(T);
-    memcpy(dest, &src, size);
+#if QT_HAS_BUILTIN(__builtin_memcpy)
+    __builtin_memcpy
+#else
+    memcpy
+#endif
+            (dest, &src, size);
 }
-template <typename T> inline T qFromUnaligned(const uchar *src)
+
+template <typename T> Q_ALWAYS_INLINE T qFromUnaligned(const uchar *src)
 {
     T dest;
     const size_t size = sizeof(T);
-    memcpy(&dest, src, size);
+#if QT_HAS_BUILTIN(__builtin_memcpy)
+    __builtin_memcpy
+#else
+    memcpy
+#endif
+            (&dest, src, size);
     return dest;
 }
 
@@ -87,12 +103,6 @@ template <typename T> inline T qFromUnaligned(const uchar *src)
 */
 template <typename T> T qbswap(T source);
 
-#ifdef __has_builtin
-#  define QT_HAS_BUILTIN(x)     __has_builtin(x)
-#else
-#  define QT_HAS_BUILTIN(x)     0
-#endif
-
 // GCC 4.3 implemented all the intrinsics, but the 16-bit one only got implemented in 4.8;
 // Clang 2.6 implemented the 32- and 64-bit but waited until 3.2 to implement the 16-bit one
 #if (defined(Q_CC_GNU) && Q_CC_GNU >= 403) || QT_HAS_BUILTIN(__builtin_bswap32)

src/corelib/global/qendian.qdoc

@@ -33,6 +33,29 @@
     little and big endian representations of numbers.
 */
 
+/*!
+    \internal
+    \fn T qFromUnaligned(const uchar *ptr)
+    \since 5.5
+
+    Loads a \c{T} from address \a ptr, which may be misaligned.
+
+    Use of this function avoids the undefined behavior that the C++ standard
+    otherwise attributes to unaligned loads.
+*/
+
+/*!
+    \internal
+    \fn void qToUnaligned(T t, uchar *ptr)
+    \since 4.5
+
+    Stores \a t to address \a ptr, which may be misaligned.
+
+    Use of this function avoids the undefined behavior that the C++ standard
+    otherwise attributes to unaligned stores.
+*/
+
+
 /*!
     \fn T qFromBigEndian(const uchar *src)
     \since 4.3

src/corelib/json/qjson_p.h

@@ -402,7 +402,7 @@ public:
             // pack with itself, we'll discard the high part anyway
             chunk = _mm_packus_epi16(chunk, chunk);
             // unaligned 64-bit store
-            qUnalignedStore(l + i, _mm_cvtsi128_si64(chunk));
+            qToUnaligned(_mm_cvtsi128_si64(chunk), l + i);
             i += 8;
         }
 #  endif

src/corelib/mimetypes/qmimemagicrule.cpp

@@ -42,7 +42,6 @@
 #include <QtCore/QList>
 #include <QtCore/QDebug>
 #include <qendian.h>
-#include <private/qsimd_p.h> // for qUnalignedLoad
 
 QT_BEGIN_NAMESPACE
 
@@ -177,7 +176,7 @@ static bool matchNumber(const QMimeMagicRulePrivate *d, const QByteArray &data)
     const char *p = data.constData() + d->startPos;
     const char *e = data.constData() + qMin(data.size() - int(sizeof(T)), d->endPos + 1);
     for ( ; p <= e; ++p) {
-        if ((qUnalignedLoad<T>(p) & mask) == (value & mask))
+        if ((qFromUnaligned<T>(reinterpret_cast<const uchar *>(p)) & mask) == (value & mask))
             return true;
     }
 

src/corelib/tools/qbitarray.cpp

@@ -35,6 +35,7 @@
 #include <qalgorithms.h>
 #include <qdatastream.h>
 #include <qdebug.h>
+#include <qendian.h>
 #include <string.h>
 
 QT_BEGIN_NAMESPACE
@@ -162,25 +163,6 @@ QBitArray::QBitArray(int size, bool value)
     Same as size().
 */
 
-template <typename T> T qUnalignedLoad(const uchar *ptr)
-{
-    /*
-     * Testing with different compilers shows that they all optimize the memcpy
-     * call away and replace with direct loads whenever possible. On x86 and PPC,
-     * GCC does direct unaligned loads; on MIPS, it generates a pair of load-left
-     * and load-right instructions. ICC and Clang do the same on x86. This is both
-     * 32- and 64-bit.
-     *
-     * On ARM cores without unaligned loads, the compiler leaves a call to
-     * memcpy.
-     */
-
-    T u;
-    memcpy(&u, ptr, sizeof(u));
-    return u;
-}
-
-
 /*!
     If \a on is true, this function returns the number of
     1-bits stored in the bit array; otherwise the number
@@ -196,17 +178,17 @@ int QBitArray::count(bool on) const
     const quint8 *const end = reinterpret_cast<const quint8 *>(d.end());
 
     while (bits + 7 <= end) {
-        quint64 v = qUnalignedLoad<quint64>(bits);
+        quint64 v = qFromUnaligned<quint64>(bits);
         bits += 8;
         numBits += int(qPopulationCount(v));
     }
     if (bits + 3 <= end) {
-        quint32 v = qUnalignedLoad<quint32>(bits);
+        quint32 v = qFromUnaligned<quint32>(bits);
         bits += 4;
         numBits += int(qPopulationCount(v));
     }
     if (bits + 1 < end) {
-        quint16 v = qUnalignedLoad<quint16>(bits);
+        quint16 v = qFromUnaligned<quint16>(bits);
         bits += 2;
         numBits += int(qPopulationCount(v));
     }

src/corelib/tools/qhash.cpp

@@ -51,6 +51,7 @@
 #include <qbytearray.h>
 #include <qdatetime.h>
 #include <qbasicatomic.h>
+#include <qendian.h>
 #include <private/qsimd_p.h>
 
 #ifndef QT_BOOTSTRAPPED
@@ -105,24 +106,24 @@ static uint crc32(const Char *ptr, size_t len, uint h)
 
     p += 8;
     for ( ; p <= e; p += 8)
-        h2 = _mm_crc32_u64(h2, qUnalignedLoad<qlonglong>(p - 8));
+        h2 = _mm_crc32_u64(h2, qFromUnaligned<qlonglong>(p - 8));
     h = h2;
     p -= 8;
 
     len = e - p;
     if (len & 4) {
-        h = _mm_crc32_u32(h, qUnalignedLoad<uint>(p));
+        h = _mm_crc32_u32(h, qFromUnaligned<uint>(p));
         p += 4;
     }
 #  else
     p += 4;
     for ( ; p <= e; p += 4)
-        h = _mm_crc32_u32(h, qUnalignedLoad<uint>(p - 4));
+        h = _mm_crc32_u32(h, qFromUnaligned<uint>(p - 4));
     p -= 4;
     len = e - p;
 #  endif
     if (len & 2) {
-        h = _mm_crc32_u16(h, qUnalignedLoad<ushort>(p));
+        h = _mm_crc32_u16(h, qFromUnaligned<ushort>(p));
         p += 2;
     }
     if (sizeof(Char) == 1 && len & 1)

src/corelib/tools/qsimd.cpp

@@ -716,26 +716,4 @@ 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

src/corelib/tools/qsimd_p.h

@@ -476,43 +476,6 @@ 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)
 
-// these defines are copied from qendian.h
-// in Qt 5.7, they have been moved to qglobal.h
-// drop them when merging this to 5.7
-#ifdef __has_builtin
-#  define QT_HAS_BUILTIN(x)     __has_builtin(x)
-#else
-#  define QT_HAS_BUILTIN(x)     0
-#endif
-
-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);
-}
-
-#undef QT_HAS_BUILTIN
-
 QT_END_NAMESPACE
 
 #endif // QSIMD_P_H

src/corelib/tools/qstring.cpp

@@ -577,7 +577,7 @@ 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(qUnalignedLoad<long long>(c + offset));
+        __m128i chunk = _mm_cvtsi64_si128(qFromUnaligned<long long>(c + offset));
         __m128i secondHalf = _mm_unpacklo_epi8(chunk, nullmask);
 
         __m128i ucdata = _mm_loadu_si128((const __m128i*)(uc + offset));