Fix alignment of vararg buffer allocas.

Since we do 8-byte loads for va_arg of double, make sure the vararg buffer
alloca is 8-byte aligned.

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/Transforms/NaCl/ExpandVarArgs.cpp b/lib/Transforms/NaCl/ExpandVarArgs.cpp
index 1b605b79ee..6f41046850 100644
--- a/lib/Transforms/NaCl/ExpandVarArgs.cpp
+++ b/lib/Transforms/NaCl/ExpandVarArgs.cpp
@@ -240,7 +240,8 @@ static bool ExpandVarArgCall(InstType *Call, DataLayout *DL) {
   // start of the function so that we don't leak space if the function
   // is called in a loop.
   Function *Func = Call->getParent()->getParent();
-  Instruction *Buf = new AllocaInst(VarArgsTy, "vararg_buffer");
+  AllocaInst *Buf = new AllocaInst(VarArgsTy, "vararg_buffer");
+  Buf->setAlignment(8); // XXX EMSCRIPTEN: Align for 8-byte aligned doubles.
   Func->getEntryBlock().getInstList().push_front(Buf);
 
   // Call llvm.lifetime.start/end intrinsics to indicate that Buf is