Weak relaxing of the constraints on atomics in MemoryDependencyAnalysis

[oota-llvm.git] / lib / IR / Function.cpp

diff --git a/lib/IR/Function.cpp b/lib/IR/Function.cpp
index 14435711bb6162cbeb3d295c367f67482bd698a3..f1fe6604333462a01f5b483a1243404f5212a82f 100644 (file)
--- a/lib/IR/Function.cpp
+++ b/lib/IR/Function.cpp
@@ -77,11 +77,17 @@ unsigned Argument::getArgNo() const {
 }
 
 /// hasNonNullAttr - Return true if this argument has the nonnull attribute on
-/// it in its containing function.
+/// it in its containing function. Also returns true if at least one byte is
+/// known to be dereferenceable and the pointer is in addrspace(0).
 bool Argument::hasNonNullAttr() const {
   if (!getType()->isPointerTy()) return false;
-  return getParent()->getAttributes().
-    hasAttribute(getArgNo()+1, Attribute::NonNull);
+  if (getParent()->getAttributes().
+        hasAttribute(getArgNo()+1, Attribute::NonNull))
+    return true;
+  else if (getDereferenceableBytes() > 0 &&
+           getType()->getPointerAddressSpace() == 0)
+    return true;
+  return false;
 }
 
 /// hasByValAttr - Return true if this argument has the byval attribute on it
@@ -113,6 +119,12 @@ unsigned Argument::getParamAlignment() const {
 
 }
 
+uint64_t Argument::getDereferenceableBytes() const {
+  assert(getType()->isPointerTy() &&
+         "Only pointers have dereferenceable bytes");
+  return getParent()->getDereferenceableBytes(getArgNo()+1);
+}
+
 /// hasNestAttr - Return true if this argument has the nest attribute on
 /// it in its containing function.
 bool Argument::hasNestAttr() const {
@@ -154,6 +166,20 @@ bool Argument::hasReturnedAttr() const {
     hasAttribute(getArgNo()+1, Attribute::Returned);
 }
 
+/// hasZExtAttr - Return true if this argument has the zext attribute on it in
+/// its containing function.
+bool Argument::hasZExtAttr() const {
+  return getParent()->getAttributes().
+    hasAttribute(getArgNo()+1, Attribute::ZExt);
+}
+
+/// hasSExtAttr Return true if this argument has the sext attribute on it in its
+/// containing function.
+bool Argument::hasSExtAttr() const {
+  return getParent()->getAttributes().
+    hasAttribute(getArgNo()+1, Attribute::SExt);
+}
+
 /// Return true if this argument has the readonly or readnone attribute on it
 /// in its containing function.
 bool Argument::onlyReadsMemory() const {