1 files changed, 10 insertions, 39 deletions

diff --git a/src/corelib/tools/qelapsedtimer_win.cpp b/src/corelib/tools/qelapsedtimer_win.cpp
index 532d61d504..520126d262 100644
--- a/src/corelib/tools/qelapsedtimer_win.cpp
+++ b/src/corelib/tools/qelapsedtimer_win.cpp
@@ -40,35 +40,21 @@
 #include "qelapsedtimer.h"
 #include <qt_windows.h>
 
-typedef ULONGLONG (WINAPI *PtrGetTickCount64)(void);
-#if defined(Q_OS_WINRT)
-    static const PtrGetTickCount64 ptrGetTickCount64 = &GetTickCount64;
-#else
-    static PtrGetTickCount64 ptrGetTickCount64 = 0;
-#endif
-
 QT_BEGIN_NAMESPACE
 
 // Result of QueryPerformanceFrequency, 0 indicates that the high resolution timer is unavailable
 static quint64 counterFrequency = 0;
 
-static void resolveLibs()
+static void resolveCounterFrequency()
 {
     static bool done = false;
     if (done)
         return;
 
-#if !defined(Q_OS_WINRT)
-    // try to get GetTickCount64 from the system
-    HMODULE kernel32 = GetModuleHandleW(L"kernel32");
-    if (!kernel32)
-        return;
-    ptrGetTickCount64 = (PtrGetTickCount64)GetProcAddress(kernel32, "GetTickCount64");
-#endif // !Q_OS_WINRT
-
     // Retrieve the number of high-resolution performance counter ticks per second
     LARGE_INTEGER frequency;
     if (!QueryPerformanceFrequency(&frequency)) {
+        qFatal("QueryPerformanceFrequency failed, even though Microsoft documentation promises it wouldn't.");
         counterFrequency = 0;
     } else {
         counterFrequency = frequency.QuadPart;
@@ -92,35 +78,20 @@ static inline qint64 ticksToNanoseconds(qint64 ticks)
 
 static quint64 getTickCount()
 {
-    resolveLibs();
+    resolveCounterFrequency();
 
     // This avoids a division by zero and disables the high performance counter if it's not available
     if (counterFrequency > 0) {
         LARGE_INTEGER counter;
 
-        if (QueryPerformanceCounter(&counter)) {
-            return counter.QuadPart;
-        } else {
-            qWarning("QueryPerformanceCounter failed, although QueryPerformanceFrequency succeeded.");
-            return 0;
-        }
+        bool ok = QueryPerformanceCounter(&counter);
+        Q_ASSERT_X(ok, "QElapsedTimer::start()",
+                   "QueryPerformanceCounter failed, although QueryPerformanceFrequency succeeded.");
+        Q_UNUSED(ok);
+        return counter.QuadPart;
     }
 
-#ifndef Q_OS_WINRT
-    if (ptrGetTickCount64)
-        return ptrGetTickCount64();
-
-    static quint32 highdword = 0;
-    static quint32 lastval = 0;
-    quint32 val = GetTickCount();
-    if (val < lastval)
-        ++highdword;
-    lastval = val;
-    return val | (quint64(highdword) << 32);
-#else // !Q_OS_WINRT
-    // ptrGetTickCount64 is always set on WinRT but GetTickCount is not available
-    return ptrGetTickCount64();
-#endif // Q_OS_WINRT
+    return GetTickCount64();
 }
 
 quint64 qt_msectime()
@@ -130,7 +101,7 @@ quint64 qt_msectime()
 
 QElapsedTimer::ClockType QElapsedTimer::clockType() Q_DECL_NOTHROW
 {
-    resolveLibs();
+    resolveCounterFrequency();
 
     if (counterFrequency > 0)
         return PerformanceCounter;