Support MSAN with Subzero JIT compiled code.

src/Common/Memory.cpp

@@ -234,9 +234,9 @@ void deallocateExecutable(void *memory, size_t bytes)
 
 void clear(uint16_t *memory, uint16_t element, size_t count)
 {
-	#if defined(_MSC_VER) && defined(__x86__)
+	#if defined(_MSC_VER) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__stosw(memory, element, count);
-	#elif defined(__GNUC__) && defined(__x86__)
+	#elif defined(__GNUC__) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__asm__("rep stosw" : : "D"(memory), "a"(element), "c"(count));
 	#else
 		for(size_t i = 0; i < count; i++)
@@ -248,9 +248,9 @@ void clear(uint16_t *memory, uint16_t element, size_t count)
 
 void clear(uint32_t *memory, uint32_t element, size_t count)
 {
-	#if defined(_MSC_VER) && defined(__x86__)
+	#if defined(_MSC_VER) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__stosd((unsigned long*)memory, element, count);
-	#elif defined(__GNUC__) && defined(__x86__)
+	#elif defined(__GNUC__) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__asm__("rep stosl" : : "D"(memory), "a"(element), "c"(count));
 	#else
 		for(size_t i = 0; i < count; i++)

src/Reactor/SubzeroReactor.cpp

@@ -26,6 +26,11 @@
 
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/raw_os_ostream.h"
+#include "llvm/Support/Compiler.h"
+
+#if __has_feature(memory_sanitizer)
+#include <sanitizer/msan_interface.h>
+#endif
 
 #if defined(_WIN32)
 #ifndef WIN32_LEAN_AND_MEAN
@@ -894,6 +899,17 @@ namespace sw
 
 	Value *Nucleus::createStore(Value *value, Value *ptr, Type *type, bool isVolatile, unsigned int align)
 	{
+		#if __has_feature(memory_sanitizer)
+			// Mark all (non-stack) memory writes as initialized by calling __msan_unpoison
+			if(align != 0)
+			{
+				auto call = Ice::InstCall::create(::function, 2, nullptr, ::context->getConstantInt64(reinterpret_cast<intptr_t>(__msan_unpoison)), false);
+				call->addArg(ptr);
+				call->addArg(::context->getConstantInt64(typeSize(type)));
+				::basicBlock->appendInst(call);
+			}
+		#endif
+
 		int valueType = (int)reinterpret_cast<intptr_t>(type);
 
 		if((valueType & EmulatedBits) && (align != 0))   // Narrow vector not stored on stack.

src/Renderer/Blitter.cpp

@@ -141,13 +141,10 @@ namespace sw
 			return;
 		}
 
-		// The memory sanitizer doesn't work with JIT compiled code
-		#if !defined(MEMORY_SANITIZER)
-			if(blitReactor(source, sourceRect, dest, destRect, options))
-			{
-				return;
-			}
-		#endif
+		if(blitReactor(source, sourceRect, dest, destRect, options))
+		{
+			return;
+		}
 
 		SliceRectF sRect = sourceRect;
 		SliceRect dRect = destRect;