fix PR8769, a miscompilation by inliner when inlining a function with a byval
argument. The generated alloca has to have at least the alignment of the
byval, if not, the client may be making assumptions that the new alloca won't
satisfy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122234 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 5cf0fed..3f50ccd 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -252,7 +252,6 @@
CalledFunc->isDeclaration() || // call, or call to a vararg function!
CalledFunc->getFunctionType()->isVarArg()) return false;
-
// If the call to the callee is not a tail call, we must clear the 'tail'
// flags on any calls that we inline.
bool MustClearTailCallFlags =
@@ -308,14 +307,19 @@
if (CalledFunc->paramHasAttr(ArgNo+1, Attribute::ByVal) &&
!CalledFunc->onlyReadsMemory()) {
const Type *AggTy = cast<PointerType>(I->getType())->getElementType();
- const Type *VoidPtrTy =
- Type::getInt8PtrTy(Context);
+ const Type *VoidPtrTy = Type::getInt8PtrTy(Context);
// Create the alloca. If we have TargetData, use nice alignment.
unsigned Align = 1;
- if (IFI.TD) Align = IFI.TD->getPrefTypeAlignment(AggTy);
- Value *NewAlloca = new AllocaInst(AggTy, 0, Align,
- I->getName(),
+ if (IFI.TD)
+ Align = IFI.TD->getPrefTypeAlignment(AggTy);
+
+ // If the byval had an alignment specified, we *must* use at least that
+ // alignment, as it is required by the byval argument (and uses of the
+ // pointer inside the callee).
+ Align = std::max(Align, CalledFunc->getParamAlignment(ArgNo+1));
+
+ Value *NewAlloca = new AllocaInst(AggTy, 0, Align, I->getName(),
&*Caller->begin()->begin());
// Emit a memcpy.
const Type *Tys[3] = {VoidPtrTy, VoidPtrTy, Type::getInt64Ty(Context)};