Add an inalloca flag to allocas

Summary:
The only current use of this flag is to mark the alloca as dynamic, even
if its in the entry block.  The stack adjustment for the alloca can
never be folded into the prologue because the call may clear it and it
has to be allocated at the top of the stack.

Reviewers: majnemer

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2571

llvm-svn: 199525

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index bb6bef7..c1fa372 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -92,6 +92,13 @@ bool Argument::hasInAllocaAttr() const {
     hasAttribute(getArgNo()+1, Attribute::InAlloca);
 }
 
+bool Argument::hasByValOrInAllocaAttr() const {
+  if (!getType()->isPointerTy()) return false;
+  AttributeSet Attrs = getParent()->getAttributes();
+  return Attrs.hasAttribute(getArgNo() + 1, Attribute::ByVal) ||
+         Attrs.hasAttribute(getArgNo() + 1, Attribute::InAlloca);
+}
+
 unsigned Argument::getParamAlignment() const {
   assert(getType()->isPointerTy() && "Only pointers have alignments");
   return getParent()->getParamAlignment(getArgNo()+1);