From b69aaf04e9a3e40124d1063271deba396eb775b6 Mon Sep 17 00:00:00 2001
From: Bartosz Taudul <wolf.pld@gmail.com>
Date: Tue, 7 Apr 2020 22:01:31 +0200
Subject: [PATCH] Add support for QPC timer.

---
 client/TracyProfiler.cpp | 13 ++++++++++++-
 client/TracyProfiler.hpp |  8 ++++++++
 client/TracySysTrace.cpp |  4 ++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/client/TracyProfiler.cpp b/client/TracyProfiler.cpp
index efe09a81..bf5d8a31 100644
--- a/client/TracyProfiler.cpp
+++ b/client/TracyProfiler.cpp
@@ -220,6 +220,7 @@ static void InitFailure( const char* msg )
 
 static int64_t SetupHwTimer()
 {
+#ifndef TRACY_TIMER_QPC
     uint32_t regs[4];
     CpuId( regs, 0x80000001 );
     if( !( regs[3] & ( 1 << 27 ) ) ) InitFailure( "CPU doesn't support RDTSCP instruction." );
@@ -229,9 +230,10 @@ static int64_t SetupHwTimer()
         const char* noCheck = getenv( "TRACY_NO_INVARIANT_CHECK" );
         if( !noCheck || noCheck[0] != '1' )
         {
-            InitFailure( "CPU doesn't support invariant TSC.\nDefine TRACY_NO_INVARIANT_CHECK=1 to ignore this error, *if you know what you are doing*." );
+            InitFailure( "CPU doesn't support invariant TSC.\nDefine TRACY_NO_INVARIANT_CHECK=1 to ignore this error, *if you know what you are doing*.\nAlternatively you may rebuild the application with the TRACY_TIMER_QPC define to use lower resolution timer." );
         }
     }
+#endif
 
     return Profiler::GetTime();
 }
@@ -2786,6 +2788,15 @@ void Profiler::SendCodeLocation( uint64_t ptr )
 #endif
 }
 
+#if ( defined _WIN32 || defined __CYGWIN__ ) && defined TRACY_TIMER_QPC
+int64_t Profiler::GetTimeQpc()
+{
+    LARGE_INTEGER t;
+    QueryPerformanceCounter( &t );
+    return t.QuadPart;
+}
+#endif
+
 }
 
 #ifdef __cplusplus
diff --git a/client/TracyProfiler.hpp b/client/TracyProfiler.hpp
index 55e19c46..f5deb9eb 100644
--- a/client/TracyProfiler.hpp
+++ b/client/TracyProfiler.hpp
@@ -131,7 +131,11 @@ public:
         return std::chrono::duration_cast<std::chrono::nanoseconds>( std::chrono::high_resolution_clock::now().time_since_epoch() ).count();
 #    endif
 #  elif defined _WIN32 || defined __CYGWIN__
+#    ifdef TRACY_TIMER_QPC
+        return GetTimeQpc();
+#    else
         return int64_t( __rdtsc() );
+#    endif
 #  elif defined __i386 || defined _M_IX86
         uint32_t eax, edx;
         asm volatile ( "rdtsc" : "=a" (eax), "=d" (edx) );
@@ -609,6 +613,10 @@ private:
         GetProfiler().m_serialQueue.commit_next();
     }
 
+#if ( defined _WIN32 || defined __CYGWIN__ ) && defined TRACY_TIMER_QPC
+    static int64_t GetTimeQpc();
+#endif
+
     double m_timerMul;
     uint64_t m_resolution;
     uint64_t m_delay;
diff --git a/client/TracySysTrace.cpp b/client/TracySysTrace.cpp
index fd7dd870..4241f3ea 100644
--- a/client/TracySysTrace.cpp
+++ b/client/TracySysTrace.cpp
@@ -226,7 +226,11 @@ bool SysTraceStart( int64_t& samplingPeriod )
     s_prop->LogFileMode = EVENT_TRACE_REAL_TIME_MODE;
     s_prop->Wnode.BufferSize = psz;
     s_prop->Wnode.Flags = WNODE_FLAG_TRACED_GUID;
+#ifdef TRACY_TIMER_QPC
+    s_prop->Wnode.ClientContext = 1;
+#else
     s_prop->Wnode.ClientContext = 3;
+#endif
     s_prop->Wnode.Guid = SystemTraceControlGuid;
     s_prop->BufferSize = 1024;
     s_prop->LoggerNameOffset = sizeof( EVENT_TRACE_PROPERTIES );