Reland r374450 with Richard Smith's comments and test fixed.
The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment. Instead, we're just
assuming the maximum possible alignment.
Differential Revision: https://reviews.llvm.org/D68824
llvm-svn: 374562
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 682a7cc..2ec9e91 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4569,7 +4569,7 @@
llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment());
llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(Alignment);
EmitAlignmentAssumption(Ret.getScalarVal(), RetTy, Loc, AA->getLocation(),
- AlignmentCI->getZExtValue(), OffsetValue);
+ AlignmentCI, OffsetValue);
} else if (const auto *AA = TargetDecl->getAttr<AllocAlignAttr>()) {
llvm::Value *AlignmentVal = CallArgs[AA->getParamIndex().getLLVMIndex()]
.getRValue(*this)