Fix LLVM alloca array size type

https://llvm.org/docs/LangRef.html#alloca-instruction does not specify the type of the 'NumElements' parameter explicitly, but it is multiplied by sizeof(<type>), which itself is of type size_t and thus 64-bit on a 64-bit platform. This assumption is made by MemorySanitizer when it emits instructions corresponding to this multiplication, which get constant folded and requires both operands to be of the same bit size. Bug: b/155148722 Change-Id: I432e69bfcea4d40ce7b593637fd242bc1a25a714 Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49888Tested-by: Nicolas Capens <nicolascapens@google.com> Reviewed-by: Antonio Maiorano <amaiorano@google.com> Kokoro-Result: kokoro <noreply+kokoro@google.com>

Fix LLVM alloca array size type
19f01495 · Nicolas Capens · Nicolas Capens · 47c3ca10 · 19f01495
Commit 19f01495 authored Nov 02, 2020 by Nicolas Capens Committed by Nicolas Capens Nov 04, 2020
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LLVMReactor.cpp src/Reactor/LLVMReactor.cpp +3 -2

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--- a/src/Reactor/LLVMReactor.cpp
+++ b/src/Reactor/LLVMReactor.cpp
@@ -622,7 +622,8 @@ Value *Nucleus::allocateStackVariable(Type *type, int arraySize)
 	if(arraySize)
 	{
-		declaration = new llvm::AllocaInst(T(type), 0, V(Nucleus::createConstantInt(arraySize)), align);
+		Value *size = (sizeof(size_t) == 8) ? Nucleus::createConstantLong(arraySize) : Nucleus::createConstantInt(arraySize);
+		declaration = new llvm::AllocaInst(T(type), 0, V(size), align);
 	}
 	else
 	{
@@ -1101,7 +1102,7 @@ void Nucleus::createMaskedStore(Value *ptr, Value *val, Value *mask, unsigned in
 			jit->builder->SetInsertPoint(mergeBlock);
 		}
 	}
-}  // namespace rr
+}
 static llvm::Value *createGather(llvm::Value *base, llvm::Type *elTy, llvm::Value *offsets, llvm::Value *mask, unsigned int alignment, bool zeroMaskedLanes)
 {