SH-3406 WIP convert fast timers to lltrace system

improved unit tests for LLUnit
renamed LLUnit to LLUnitImplicit with LLUnit being reserved for
explicit units

13 files changed, 237 insertions, 95 deletions

diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index e1f2eb44fd..5b76703af7 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -342,7 +342,7 @@ if (LL_TESTS)
   LL_ADD_INTEGRATION_TEST(llstring "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(lltreeiterators "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(lluri "" "${test_libs}")
-  LL_ADD_INTEGRATION_TEST(llunit "" "${test_libs}")
+  LL_ADD_INTEGRATION_TEST(llunits "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(reflection "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(stringize "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(lleventdispatcher "" "${test_libs}")
diff --git a/indra/llcommon/llfasttimer.cpp b/indra/llcommon/llfasttimer.cpp
index cf7655acf7..37e0fbac0a 100644
--- a/indra/llcommon/llfasttimer.cpp
+++ b/indra/llcommon/llfasttimer.cpp
@@ -166,7 +166,7 @@ U64 TimeBlock::countsPerSecond() // counts per second for the *64-bit* timer
 		firstcall = false;
 	}
 #endif
-	return sCPUClockFrequency;
+	return sCPUClockFrequency.value();
 }
 #endif
 
@@ -408,7 +408,7 @@ void TimeBlock::nextFrame()
 			}
 			call_count++;
 
-			LLUnit<LLUnits::Seconds, F64> total_time = 0;
+			LLUnit<LLUnits::Seconds, F64> total_time(0);
 			LLSD sd;
 
 			{
@@ -479,7 +479,7 @@ void TimeBlock::dumpCurTimes()
 		}
 
 		out_str << timerp->getName() << " " 
-			<< std::setprecision(3) << total_time_ms.as<LLUnits::Milliseconds, F32>() << " ms, "
+			<< std::setprecision(3) << total_time_ms.as<LLUnits::Milliseconds, F32>().value() << " ms, "
 			<< num_calls << " calls";
 
 		llinfos << out_str.str() << llendl;
diff --git a/indra/llcommon/llleap.cpp b/indra/llcommon/llleap.cpp
index 0a57ef1c48..84d2a12f65 100644
--- a/indra/llcommon/llleap.cpp
+++ b/indra/llcommon/llleap.cpp
@@ -394,7 +394,7 @@ public:
         LLProcess::WritePipe& childin(mChild->getWritePipe(LLProcess::STDIN));
         LLEventPump& mainloop(LLEventPumps::instance().obtain("mainloop"));
         LLSD nop;
-        F64 until(LLTimer::getElapsedSeconds() + 2);
+        F64 until = (LLTimer::getElapsedSeconds() + 2).value();
         while (childin.size() && LLTimer::getElapsedSeconds() < until)
         {
             mainloop.post(nop);
diff --git a/indra/llcommon/llprocessor.cpp b/indra/llcommon/llprocessor.cpp
index 6fe53396ca..5ddfa6fcef 100644
--- a/indra/llcommon/llprocessor.cpp
+++ b/indra/llcommon/llprocessor.cpp
@@ -875,7 +875,7 @@ LLProcessorInfo::LLProcessorInfo() : mImpl(NULL)
 
 
 LLProcessorInfo::~LLProcessorInfo() {}
-LLUnit<LLUnits::Megahertz, F64> LLProcessorInfo::getCPUFrequency() const { return mImpl->getCPUFrequency(); }
+LLUnitImplicit<LLUnits::Megahertz, F64> LLProcessorInfo::getCPUFrequency() const { return mImpl->getCPUFrequency(); }
 bool LLProcessorInfo::hasSSE() const { return mImpl->hasSSE(); }
 bool LLProcessorInfo::hasSSE2() const { return mImpl->hasSSE2(); }
 bool LLProcessorInfo::hasAltivec() const { return mImpl->hasAltivec(); }
diff --git a/indra/llcommon/llprocessor.h b/indra/llcommon/llprocessor.h
index 2a21a5c115..fbd427f484 100644
--- a/indra/llcommon/llprocessor.h
+++ b/indra/llcommon/llprocessor.h
@@ -37,7 +37,7 @@ public:
 	LLProcessorInfo(); 
  	~LLProcessorInfo();
 
-	LLUnit<LLUnits::Megahertz, F64> getCPUFrequency() const;
+	LLUnitImplicit<LLUnits::Megahertz, F64> getCPUFrequency() const;
 	bool hasSSE() const;
 	bool hasSSE2() const;
 	bool hasAltivec() const;
diff --git a/indra/llcommon/lltimer.cpp b/indra/llcommon/lltimer.cpp
index 26063beff0..838155d54d 100644
--- a/indra/llcommon/lltimer.cpp
+++ b/indra/llcommon/lltimer.cpp
@@ -285,14 +285,14 @@ LLTimer::~LLTimer()
 }
 
 // static
-LLUnit<LLUnits::Microseconds, U64> LLTimer::getTotalTime()
+LLUnitImplicit<LLUnits::Microseconds, U64> LLTimer::getTotalTime()
 {
 	// simply call into the implementation function.
 	return totalTime();
 }	
 
 // static
-LLUnit<LLUnits::Seconds, F64> LLTimer::getTotalSeconds()
+LLUnitImplicit<LLUnits::Seconds, F64> LLTimer::getTotalSeconds()
 {
 	return U64_to_F64(getTotalTime()) * USEC_TO_SEC_F64;
 }
@@ -341,23 +341,23 @@ U64 getElapsedTimeAndUpdate(U64& lastClockCount)
 }
 
 
-LLUnit<LLUnits::Seconds, F64> LLTimer::getElapsedTimeF64() const
+LLUnitImplicit<LLUnits::Seconds, F64> LLTimer::getElapsedTimeF64() const
 {
 	U64 last = mLastClockCount;
 	return (F64)getElapsedTimeAndUpdate(last) * gClockFrequencyInv;
 }
 
-LLUnit<LLUnits::Seconds, F32> LLTimer::getElapsedTimeF32() const
+LLUnitImplicit<LLUnits::Seconds, F32> LLTimer::getElapsedTimeF32() const
 {
 	return (F32)getElapsedTimeF64();
 }
 
-LLUnit<LLUnits::Seconds, F64> LLTimer::getElapsedTimeAndResetF64()
+LLUnitImplicit<LLUnits::Seconds, F64> LLTimer::getElapsedTimeAndResetF64()
 {
 	return (F64)getElapsedTimeAndUpdate(mLastClockCount) * gClockFrequencyInv;
 }
 
-LLUnit<LLUnits::Seconds, F32> LLTimer::getElapsedTimeAndResetF32()
+LLUnitImplicit<LLUnits::Seconds, F32> LLTimer::getElapsedTimeAndResetF32()
 {
 	return (F32)getElapsedTimeAndResetF64();
 }
@@ -370,7 +370,7 @@ void  LLTimer::setTimerExpirySec(F32 expiration)
 		+ (U64)((F32)(expiration * gClockFrequency));
 }
 
-LLUnit<LLUnits::Seconds, F32> LLTimer::getRemainingTimeF32() const
+LLUnitImplicit<LLUnits::Seconds, F32> LLTimer::getRemainingTimeF32() const
 {
 	U64 cur_ticks = get_clock_count();
 	if (cur_ticks > mExpirationTicks)
diff --git a/indra/llcommon/lltimer.h b/indra/llcommon/lltimer.h
index 5cb2b18111..0ba87d1e15 100644
--- a/indra/llcommon/lltimer.h
+++ b/indra/llcommon/lltimer.h
@@ -67,16 +67,16 @@ public:
 
 	// Return a high precision number of seconds since the start of
 	// this application instance.
-	static LLUnit<LLUnits::Seconds, F64> getElapsedSeconds()
+	static LLUnitImplicit<LLUnits::Seconds, F64> getElapsedSeconds()
 	{
 		return sTimer->getElapsedTimeF64();
 	}
 
 	// Return a high precision usec since epoch
-	static LLUnit<LLUnits::Microseconds, U64> getTotalTime();
+	static LLUnitImplicit<LLUnits::Microseconds, U64> getTotalTime();
 
 	// Return a high precision seconds since epoch
-	static LLUnit<LLUnits::Seconds, F64> getTotalSeconds();
+	static LLUnitImplicit<LLUnits::Seconds, F64> getTotalSeconds();
 
 
 	// MANIPULATORS
@@ -87,16 +87,16 @@ public:
 	void setTimerExpirySec(F32 expiration);
 	BOOL checkExpirationAndReset(F32 expiration);
 	BOOL hasExpired() const;
-	LLUnit<LLUnits::Seconds, F32> getElapsedTimeAndResetF32();	// Returns elapsed time in seconds with reset
-	LLUnit<LLUnits::Seconds, F64> getElapsedTimeAndResetF64();
+	LLUnitImplicit<LLUnits::Seconds, F32> getElapsedTimeAndResetF32();	// Returns elapsed time in seconds with reset
+	LLUnitImplicit<LLUnits::Seconds, F64> getElapsedTimeAndResetF64();
 
-	LLUnit<LLUnits::Seconds, F32> getRemainingTimeF32() const;
+	LLUnitImplicit<LLUnits::Seconds, F32> getRemainingTimeF32() const;
 
 	static BOOL knownBadTimer();
 
 	// ACCESSORS
-	LLUnit<LLUnits::Seconds, F32> getElapsedTimeF32() const;			// Returns elapsed time in seconds
-	LLUnit<LLUnits::Seconds, F64> getElapsedTimeF64() const;			// Returns elapsed time in seconds
+	LLUnitImplicit<LLUnits::Seconds, F32> getElapsedTimeF32() const;			// Returns elapsed time in seconds
+	LLUnitImplicit<LLUnits::Seconds, F64> getElapsedTimeF64() const;			// Returns elapsed time in seconds
 
 	bool getStarted() const { return mStarted; }
 
diff --git a/indra/llcommon/lltrace.h b/indra/llcommon/lltrace.h
index 6e6bb51e47..25d95d9670 100644
--- a/indra/llcommon/lltrace.h
+++ b/indra/llcommon/lltrace.h
@@ -435,6 +435,9 @@ namespace LLTrace
 	class TraceType<TimeBlockAccumulator::CallCountAspect>
 	:	public TraceType<TimeBlockAccumulator>
 	{
+	public:
+		typedef F32 mean_t;
+
 		TraceType(const char* name, const char* description = "")
 		:	TraceType<TimeBlockAccumulator>(name, description)
 		{}
@@ -465,7 +468,7 @@ namespace LLTrace
 		void sample(UNIT_T value)
 		{
 			T converted_value(value);
-			getPrimaryAccumulator().sample((storage_t)converted_value);
+			getPrimaryAccumulator().sample(LLUnits::rawValue(converted_value));
 		}
 	};
 
@@ -484,7 +487,7 @@ namespace LLTrace
 		void add(UNIT_T value)
 		{
 			T converted_value(value);
-			getPrimaryAccumulator().add((storage_t)converted_value);
+			getPrimaryAccumulator().add(LLUnits::rawValue(converted_value));
 		}
 	};
 }
diff --git a/indra/llcommon/lltracerecording.h b/indra/llcommon/lltracerecording.h
index 6fd1a105d3..f92281cea8 100644
--- a/indra/llcommon/lltracerecording.h
+++ b/indra/llcommon/lltracerecording.h
@@ -205,7 +205,7 @@ namespace LLTrace
 		U32 getSampleCount(const TraceType<MeasurementAccumulator<F64> >& stat) const;
 		U32 getSampleCount(const TraceType<MeasurementAccumulator<S64> >& stat) const;
 
-		LLUnit<LLUnits::Seconds, F64> getDuration() const { return mElapsedSeconds; }
+		LLUnit<LLUnits::Seconds, F64> getDuration() const { return LLUnit<LLUnits::Seconds, F64>(mElapsedSeconds); }
 
 	private:
 		friend class ThreadRecorder;
diff --git a/indra/llcommon/llunit.h b/indra/llcommon/llunit.h
index 1f3ed0237c..6b023f8287 100644
--- a/indra/llcommon/llunit.h
+++ b/indra/llcommon/llunit.h
@@ -65,6 +65,7 @@ struct ConversionFactor<BASE_UNITS_TAG, BASE_UNITS_TAG, VALUE_TYPE>
 		return 1; 
 	}
 };
+
 }
 
 template<typename UNIT_TYPE, typename STORAGE_TYPE>
@@ -73,25 +74,25 @@ struct LLUnit
 	typedef LLUnit<UNIT_TYPE, STORAGE_TYPE> self_t;
 	typedef STORAGE_TYPE storage_t;
 
+	// value initialization
 	LLUnit(storage_t value = storage_t())
 	:	mValue(value)
 	{}
 
+	// unit initialization and conversion
 	template<typename OTHER_UNIT, typename OTHER_STORAGE>
 	LLUnit(LLUnit<OTHER_UNIT, OTHER_STORAGE> other)
 	:	mValue(convert(other))
 	{}
-
-	LLUnit(self_t& other)
-	:	mValue(other.mValue)
-	{}
-
+	
+	// value assignment
 	self_t& operator = (storage_t value)
 	{
 		mValue = value;
 		return *this;
 	}
 
+	// unit assignment
 	template<typename OTHER_UNIT, typename OTHER_STORAGE>
 	self_t& operator = (LLUnit<OTHER_UNIT, OTHER_STORAGE> other)
 	{
@@ -99,11 +100,6 @@ struct LLUnit
 		return *this;
 	}
 
-	operator storage_t() const
-	{
-		return value();
-	}
-
 	storage_t value() const
 	{
 		return mValue;
@@ -157,7 +153,7 @@ struct LLUnit
 	void operator /= (LLUnit<OTHER_UNIT, OTHER_STORAGE> divisor)
 	{
 		// spurious use of dependent type to stop gcc from triggering the static assertion before instantiating the template
-		llstatic_assert(sizeof(OTHER_UNIT) == 0, "Division of unit types not supported.");
+		llstatic_assert(sizeof(OTHER_UNIT) == 0, "Illegal in-place division of unit types.");
 	}
 
 	template<typename SOURCE_UNITS, typename SOURCE_STORAGE>
@@ -169,34 +165,30 @@ struct LLUnit
 	}
 
 protected:
-
 	storage_t mValue;
 };
 
 template<typename UNIT_TYPE, typename STORAGE_TYPE>
-struct LLUnitStrict : public LLUnit<UNIT_TYPE, STORAGE_TYPE>
+struct LLUnitImplicit : public LLUnit<UNIT_TYPE, STORAGE_TYPE>
 {
-	typedef LLUnitStrict<UNIT_TYPE, STORAGE_TYPE> self_t;
+	typedef LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> self_t;
 	typedef typename LLUnit<UNIT_TYPE, STORAGE_TYPE>::storage_t storage_t;
+	typedef LLUnit<UNIT_TYPE, STORAGE_TYPE> base_t;
 
-	explicit LLUnitStrict(storage_t value = storage_t())
-	:	LLUnit<UNIT_TYPE, STORAGE_TYPE>(value)
+	LLUnitImplicit(storage_t value = storage_t())
+	:	base_t(value)
 	{}
 
 	template<typename OTHER_UNIT, typename OTHER_STORAGE>
-	LLUnitStrict(LLUnit<OTHER_UNIT, OTHER_STORAGE> other)
-	:	LLUnit<UNIT_TYPE, STORAGE_TYPE>(convert(other))
+	LLUnitImplicit(LLUnit<OTHER_UNIT, OTHER_STORAGE> other)
+	:	base_t(convert(other))
 	{}
 
-	LLUnitStrict(self_t& other)
-	:	LLUnit<UNIT_TYPE, STORAGE_TYPE>(other)
-	{}
-
-
-private:
+	// unlike LLUnit, LLUnitImplicit is *implicitly* convertable to a POD scalar (F32, S32, etc)
+	// this allows for interoperability with legacy code
 	operator storage_t() const
 	{
-		return LLUnit<UNIT_TYPE, STORAGE_TYPE>::value();
+		return value();
 	}
 };
 
@@ -204,7 +196,7 @@ private:
 // operator +
 //
 template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>
-LLUnit<STORAGE_TYPE1, UNIT_TYPE1> operator + (LLUnit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnit<UNIT_TYPE2, STORAGE_TYPE2> second)
+LLUnit<UNIT_TYPE1, STORAGE_TYPE1> operator + (LLUnit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnit<UNIT_TYPE2, STORAGE_TYPE2> second)
 {
 	LLUnit<UNIT_TYPE1, STORAGE_TYPE1> result(first);
 	result += second;
@@ -227,6 +219,30 @@ LLUnit<UNIT_TYPE, STORAGE_TYPE> operator + (SCALAR_TYPE first, LLUnit<UNIT_TYPE,
 	return result;
 }
 
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>
+LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> operator + (LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnit<UNIT_TYPE2, STORAGE_TYPE2> second)
+{
+	LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> result(first);
+	result += second;
+	return result;
+}
+
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
+LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> operator + (LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)
+{
+	LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> result(first);
+	result += second;
+	return result;
+}
+
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>
+LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> operator + (LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnitImplicit<UNIT_TYPE2, STORAGE_TYPE2> second)
+{
+	LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> result(first);
+	result += second;
+	return result;
+}
+
 //
 // operator -
 //
@@ -238,7 +254,6 @@ LLUnit<UNIT_TYPE1, STORAGE_TYPE1> operator - (LLUnit<UNIT_TYPE1, STORAGE_TYPE1>
 	return result;
 }
 
-
 template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
 LLUnit<UNIT_TYPE, STORAGE_TYPE> operator - (LLUnit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)
 {
@@ -255,6 +270,30 @@ LLUnit<UNIT_TYPE, STORAGE_TYPE> operator - (SCALAR_TYPE first, LLUnit<UNIT_TYPE,
 	return result;
 }
 
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>
+LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> operator - (LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnitImplicit<UNIT_TYPE2, STORAGE_TYPE2> second)
+{
+	LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> result(first);
+	result -= second;
+	return result;
+}
+
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
+LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> operator - (LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)
+{
+	LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> result(first);
+	result -= second;
+	return result;
+}
+
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
+LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> operator - (SCALAR_TYPE first, LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> second)
+{
+	LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> result(first);
+	result -= second;
+	return result;
+}
+
 //
 // operator *
 //
@@ -278,6 +317,26 @@ LLUnit<UNIT_TYPE1, STORAGE_TYPE1> operator * (LLUnit<UNIT_TYPE1, STORAGE_TYPE1>,
 	return LLUnit<UNIT_TYPE1, STORAGE_TYPE1>();
 }
 
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
+LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> operator * (SCALAR_TYPE first, LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> second)
+{
+	return LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE>(first * second.value());
+}
+
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
+LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> operator * (LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)
+{
+	return LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE>(first.value() * second);
+}
+
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>
+LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> operator * (LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1>, LLUnitImplicit<UNIT_TYPE2, STORAGE_TYPE2>)
+{
+	// spurious use of dependent type to stop gcc from triggering the static assertion before instantiating the template
+	llstatic_assert(sizeof(STORAGE_TYPE1) == 0, "Multiplication of unit types results in new unit type - not supported.");
+	return LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1>();
+}
+
 //
 // operator /
 //
@@ -300,23 +359,42 @@ STORAGE_TYPE1 operator / (LLUnit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnit<UNIT_T
 	return STORAGE_TYPE1(first.value() / second.value());
 }
 
-#define COMPARISON_OPERATORS(op)                                                                     \
-template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>                            \
-bool operator op (SCALAR_TYPE first, LLUnit<UNIT_TYPE, STORAGE_TYPE> second)                         \
-{                                                                                                    \
-	return first op second.value();                                                                  \
-}                                                                                                    \
-	                                                                                                 \
-template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>                            \
-bool operator op (LLUnit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)                         \
-{                                                                                                    \
-	return first.value() op second;                                                                  \
-}                                                                                                    \
-	                                                                                                 \
-template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>   \
-bool operator op (LLUnit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnit<UNIT_TYPE2, STORAGE_TYPE2> second) \
-{                                                                                                    \
-	return first.value() op first.convert(second);                                                   \
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>
+LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> operator / (LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)
+{
+	return LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE>(first.value() / second);
+}
+
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>
+STORAGE_TYPE1 operator / (LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnitImplicit<UNIT_TYPE2, STORAGE_TYPE2> second)
+{
+	// spurious use of dependent type to stop gcc from triggering the static assertion before instantiating the template
+	return STORAGE_TYPE1(first.value() / second.value());
+}
+
+#define COMPARISON_OPERATORS(op)                                                                                     \
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>                                            \
+bool operator op (SCALAR_TYPE first, LLUnit<UNIT_TYPE, STORAGE_TYPE> second)                                         \
+{                                                                                                                    \
+	return first op second.value();                                                                                  \
+}                                                                                                                    \
+	                                                                                                                 \
+template<typename UNIT_TYPE, typename STORAGE_TYPE, typename SCALAR_TYPE>                                            \
+bool operator op (LLUnit<UNIT_TYPE, STORAGE_TYPE> first, SCALAR_TYPE second)                                         \
+{                                                                                                                    \
+	return first.value() op second;                                                                                  \
+}                                                                                                                    \
+	                                                                                                                 \
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>                   \
+bool operator op (LLUnitImplicit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnitImplicit<UNIT_TYPE2, STORAGE_TYPE2> second) \
+{                                                                                                                    \
+	return first.value() op first.convert(second);                                                                   \
+}                                                                                                                    \
+	                                                                                                                 \
+template<typename UNIT_TYPE1, typename STORAGE_TYPE1, typename UNIT_TYPE2, typename STORAGE_TYPE2>                   \
+	bool operator op (LLUnit<UNIT_TYPE1, STORAGE_TYPE1> first, LLUnit<UNIT_TYPE2, STORAGE_TYPE2> second)             \
+{                                                                                                                    \
+	return first.value() op first.convert(second);                                                                   \
 }
 
 COMPARISON_OPERATORS(<)
@@ -328,6 +406,15 @@ COMPARISON_OPERATORS(!=)
 
 namespace LLUnits
 {
+template<typename T>
+T rawValue(T val) { return val; }
+
+template<typename UNIT_TYPE, typename STORAGE_TYPE> 
+STORAGE_TYPE rawValue(LLUnit<UNIT_TYPE, STORAGE_TYPE> val) { return val.value(); }
+
+template<typename UNIT_TYPE, typename STORAGE_TYPE> 
+STORAGE_TYPE rawValue(LLUnitImplicit<UNIT_TYPE, STORAGE_TYPE> val) { return val.value(); }
+
 template<typename UNIT_TYPE, typename STORAGE_TYPE> 
 struct HighestPrecisionType<LLUnit<UNIT_TYPE, STORAGE_TYPE> >
 {
@@ -361,22 +448,22 @@ struct Bytes { typedef Bytes base_unit_t; };
 LL_DECLARE_DERIVED_UNIT(1024, Bytes, Kilobytes);
 LL_DECLARE_DERIVED_UNIT(1024 * 1024, Bytes, Megabytes);
 LL_DECLARE_DERIVED_UNIT(1024 * 1024 * 1024, Bytes, Gigabytes);
-LL_DECLARE_DERIVED_UNIT((1.0 / 8.0), Bytes, Bits);
-LL_DECLARE_DERIVED_UNIT((1024 / 8), Bytes, Kilobits);
-LL_DECLARE_DERIVED_UNIT((1024 / 8), Bytes, Megabits);
-LL_DECLARE_DERIVED_UNIT((1024 * 1024 * 1024 / 8), Bytes, Gigabits);
+LL_DECLARE_DERIVED_UNIT(1.0 / 8.0, Bytes, Bits);
+LL_DECLARE_DERIVED_UNIT(1024 / 8, Bytes, Kilobits);
+LL_DECLARE_DERIVED_UNIT(1024 / 8, Bytes, Megabits);
+LL_DECLARE_DERIVED_UNIT(1024 * 1024 * 1024 / 8, Bytes, Gigabits);
 
 struct Seconds { typedef Seconds base_unit_t; };
 LL_DECLARE_DERIVED_UNIT(60, Seconds, Minutes);
 LL_DECLARE_DERIVED_UNIT(60 * 60, Seconds, Hours);
-LL_DECLARE_DERIVED_UNIT((1.0 / 1000.0), Seconds, Milliseconds);
-LL_DECLARE_DERIVED_UNIT((1.0 / (1000000.0)), Seconds, Microseconds);
-LL_DECLARE_DERIVED_UNIT((1.0 / (1000000000.0)), Seconds, Nanoseconds);
+LL_DECLARE_DERIVED_UNIT(1.0 / 1000.0, Seconds, Milliseconds);
+LL_DECLARE_DERIVED_UNIT(1.0 / 1000000.0, Seconds, Microseconds);
+LL_DECLARE_DERIVED_UNIT(1.0 / 1000000000.0, Seconds, Nanoseconds);
 
 struct Meters { typedef Meters base_unit_t; };
 LL_DECLARE_DERIVED_UNIT(1000, Meters, Kilometers);
-LL_DECLARE_DERIVED_UNIT((1.0 / 100.0), Meters, Centimeters);
-LL_DECLARE_DERIVED_UNIT((1.0 / 1000.0), Meters, Millimeters);
+LL_DECLARE_DERIVED_UNIT(1.0 / 100.0, Meters, Centimeters);
+LL_DECLARE_DERIVED_UNIT(1.0 / 1000.0, Meters, Millimeters);
 
 struct Hertz { typedef Hertz base_unit_t; };
 LL_DECLARE_DERIVED_UNIT(1000, Hertz, Kilohertz);
diff --git a/indra/llcommon/tests/llunit_test.cpp b/indra/llcommon/tests/llunits_test.cpp
index a7e9c00740..2a941e8229 100644
--- a/indra/llcommon/tests/llunit_test.cpp
+++ b/indra/llcommon/tests/llunits_test.cpp
@@ -68,7 +68,7 @@ namespace tut
 		ensure(int_quatloos.value() == 42);
 
 		float_quatloos = 42.1f;
-		ensure(float_quatloos == 42.1f);
+		ensure(float_quatloos.value() == 42.1f);
 		int_quatloos = float_quatloos;
 		ensure(int_quatloos.value() == 42);
 		LLUnit<Quatloos, U32> unsigned_int_quatloos(float_quatloos);
@@ -153,4 +153,56 @@ namespace tut
 		quatloos -= LLUnit<Latinum, F32>(1.f);
 		ensure(quatloos.value() == 1);
 	}
+
+	// implicit units
+	template<> template<>
+	void units_object_t::test<5>()
+	{
+		// 0-initialized
+		LLUnit<Quatloos, F32> quatloos(0);
+		// initialize implicit unit from explicit
+		LLUnitImplicit<Quatloos, F32> quatloos_implicit = quatloos + 1;
+		ensure(quatloos_implicit.value() == 1);
+
+		// assign implicit to explicit, or perform math operations
+		quatloos = quatloos_implicit;
+		ensure(quatloos.value() == 1);
+		quatloos += quatloos_implicit;
+		ensure(quatloos.value() == 2);
+
+		// math operations on implicits
+		quatloos_implicit = 1;
+		ensure(quatloos_implicit == 1);
+
+		quatloos_implicit += 2;
+		ensure(quatloos_implicit == 3);
+
+		quatloos_implicit *= 2;
+		ensure(quatloos_implicit == 6);
+
+		quatloos_implicit -= 1;
+		ensure(quatloos_implicit == 5);
+
+		quatloos_implicit /= 5;
+		ensure(quatloos_implicit == 1);
+
+		quatloos_implicit = quatloos_implicit + 3 + quatloos_implicit;
+		ensure(quatloos_implicit == 5);
+
+		quatloos_implicit = 10 - quatloos_implicit - 1;
+		ensure(quatloos_implicit == 4);
+
+		quatloos_implicit = 2 * quatloos_implicit * 2;
+		ensure(quatloos_implicit == 16);
+
+		F32 one_half = quatloos_implicit / (quatloos_implicit * 2);
+		ensure(one_half == 0.5f);
+
+		// implicit conversion to POD
+		F32 float_val = quatloos_implicit;
+		ensure(float_val == 16);
+
+		S32 int_val = quatloos_implicit;
+		ensure(int_val == 16);
+	}
 }
diff --git a/indra/newview/llfasttimerview.cpp b/indra/newview/llfasttimerview.cpp
index 704b914b78..1c63022527 100644
--- a/indra/newview/llfasttimerview.cpp
+++ b/indra/newview/llfasttimerview.cpp
@@ -311,11 +311,11 @@ static std::string get_tooltip(LLTrace::TimeBlock& timer, S32 history_index, LLT
 	if (history_index < 0)
 	{
 		// by default, show average number of call
-		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)(frame_recording.getPeriodMean(timer) * ms_multiplier), (S32)frame_recording.getPeriodMean(timer.callCount()));
+		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)(frame_recording.getPeriodMean(timer) * ms_multiplier).value(), (S32)frame_recording.getPeriodMean(timer.callCount()));
 	}
 	else
 	{
-		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)(frame_recording.getPrevRecordingPeriod(history_index).getSum(timer) * ms_multiplier), (S32)frame_recording.getPrevRecordingPeriod(history_index).getSum(timer.callCount()));
+		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)(frame_recording.getPrevRecordingPeriod(history_index).getSum(timer) * ms_multiplier).value(), (S32)frame_recording.getPrevRecordingPeriod(history_index).getSum(timer.callCount()));
 	}
 	return tooltip;
 }
@@ -601,22 +601,22 @@ void LLFastTimerView::draw()
 	{
 		LLUnit<LLUnits::Milliseconds, U32> ms = total_time;
 
-		tdesc = llformat("%.1f ms |", (F32)ms*.25f);
+		tdesc = llformat("%.1f ms |", (F32)ms.value()*.25f);
 		x = xleft + barw/4 - LLFontGL::getFontMonospace()->getWidth(tdesc);
 		LLFontGL::getFontMonospace()->renderUTF8(tdesc, 0, x, y, LLColor4::white,
 										LLFontGL::LEFT, LLFontGL::TOP);
 			
-		tdesc = llformat("%.1f ms |", (F32)ms*.50f);
+		tdesc = llformat("%.1f ms |", (F32)ms.value()*.50f);
 		x = xleft + barw/2 - LLFontGL::getFontMonospace()->getWidth(tdesc);
 		LLFontGL::getFontMonospace()->renderUTF8(tdesc, 0, x, y, LLColor4::white,
 										LLFontGL::LEFT, LLFontGL::TOP);
 			
-		tdesc = llformat("%.1f ms |", (F32)ms*.75f);
+		tdesc = llformat("%.1f ms |", (F32)ms.value()*.75f);
 		x = xleft + (barw*3)/4 - LLFontGL::getFontMonospace()->getWidth(tdesc);
 		LLFontGL::getFontMonospace()->renderUTF8(tdesc, 0, x, y, LLColor4::white,
 										LLFontGL::LEFT, LLFontGL::TOP);
 			
-		tdesc = llformat( "%d ms |", (U32)ms);
+		tdesc = llformat( "%d ms |", (U32)ms.value());
 		x = xleft + barw - LLFontGL::getFontMonospace()->getWidth(tdesc);
 		LLFontGL::getFontMonospace()->renderUTF8(tdesc, 0, x, y, LLColor4::white,
 										LLFontGL::LEFT, LLFontGL::TOP);
@@ -728,11 +728,11 @@ void LLFastTimerView::draw()
 					++it)
 				{
 					sublevelticks += (tidx == -1)
-						? frame_recording.getPeriodMean(**it)
-						: frame_recording.getPrevRecordingPeriod(tidx).getSum(**it);
+						? frame_recording.getPeriodMean(**it).value()
+						: frame_recording.getPrevRecordingPeriod(tidx).getSum(**it).value();
 				}
 
-				F32 subfrac = (F32)sublevelticks / (F32)total_time;
+				F32 subfrac = (F32)sublevelticks / (F32)total_time.value();
 				sublevel_dx[level] = (int)(subfrac * (F32)barw + .5f);
 
 				if (mDisplayCenter == ALIGN_CENTER)
@@ -819,7 +819,7 @@ void LLFastTimerView::draw()
 		else if (mDisplayHz)
 			tdesc = llformat("%d Hz", (int)(1.f / max_time.value()));
 		else
-			tdesc = llformat("%4.2f ms", LLUnit<LLUnits::Milliseconds, F32>(max_time).value());
+			tdesc = llformat("%4.2f ms", max_time.value());
 							
 		x = mGraphRect.mRight - LLFontGL::getFontMonospace()->getWidth(tdesc)-5;
 		y = mGraphRect.mTop - LLFontGL::getFontMonospace()->getLineHeight();
@@ -900,7 +900,7 @@ void LLFastTimerView::draw()
 				F32 x = mGraphRect.mRight - j * (F32)(mGraphRect.getWidth())/(LLTrace::TimeBlock::HISTORY_NUM-1);
 				F32 y = mDisplayHz 
 					? mGraphRect.mBottom + (1.f / time.value()) * ((F32) mGraphRect.getHeight() / (1.f / max_time.value()))
-					: mGraphRect.mBottom + time * ((F32)mGraphRect.getHeight() / max_time);
+					: mGraphRect.mBottom + time / max_time * (F32)mGraphRect.getHeight();
 				gGL.vertex2f(x,y);
 				gGL.vertex2f(x,mGraphRect.mBottom);
 			}
@@ -920,22 +920,22 @@ void LLFastTimerView::draw()
 		}
 			
 		//interpolate towards new maximum
-		max_time = lerp((F32)max_time, (F32) cur_max, LLCriticalDamp::getInterpolant(0.1f));
+		max_time = lerp(max_time.value(), cur_max.value(), LLCriticalDamp::getInterpolant(0.1f));
 		if (max_time - cur_max <= 1 ||  cur_max - max_time  <= 1)
 		{
 			max_time = llmax(LLUnit<LLUnits::Microseconds, F32>(1), LLUnit<LLUnits::Microseconds, F32>(cur_max));
 		}
 
 		max_calls = lerp((F32)max_calls, (F32) cur_max_calls, LLCriticalDamp::getInterpolant(0.1f));
-		if (llabs(max_calls - cur_max) <= 1)
+		if (llabs((S32)(max_calls - cur_max_calls)) <= 1)
 		{
 			max_calls = cur_max_calls;
 		}
 
 		// TODO: make sure alpha is correct in DisplayHz mode
 		F32 alpha_target = (max_time > cur_max)
-			? llmin((F32) max_time/ (F32) cur_max - 1.f,1.f) 
-			: llmin((F32) cur_max/ (F32) max_time - 1.f,1.f);
+			? llmin(max_time / cur_max - 1.f,1.f) 
+			: llmin(cur_max/ max_time - 1.f,1.f);
 		alpha_interp = lerp(alpha_interp, alpha_target, LLCriticalDamp::getInterpolant(0.1f));
 
 		if (mHoverID != NULL)
diff --git a/indra/newview/pipeline.cpp b/indra/newview/pipeline.cpp
index 813fc7db6a..3be19c3920 100644
--- a/indra/newview/pipeline.cpp
+++ b/indra/newview/pipeline.cpp
@@ -2747,7 +2747,7 @@ void LLPipeline::updateGeom(F32 max_dtime)
 		
 	S32 count = 0;
 	
-	max_dtime = llmax(update_timer.getElapsedTimeF32()+0.001f, LLUnit<LLUnits::Seconds, F32>(max_dtime));
+	max_dtime = llmax(update_timer.getElapsedTimeF32()+0.001f, LLUnitImplicit<LLUnits::Seconds, F32>(max_dtime));
 	LLSpatialGroup* last_group = NULL;
 	LLSpatialBridge* last_bridge = NULL;