From 5c91891cf30f937c3ad6615224f43b49e4524b59 Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Mon, 26 Sep 2011 20:15:28 +0000
Subject: Enhance alias analysis for atomic instructions a bit.  Upgrade a
 couple alias-analysis tests to the new atomic instructions.

llvm-svn: 140557
---
 llvm/lib/Analysis/AliasAnalysis.cpp | 40 +++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

(limited to 'llvm/lib/Analysis/AliasAnalysis.cpp')

diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 73cc9037216..bd132c05c32 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -237,6 +237,19 @@ AliasAnalysis::Location AliasAnalysis::getLocation(const VAArgInst *VI) {
                   VI->getMetadata(LLVMContext::MD_tbaa));
 }
 
+AliasAnalysis::Location
+AliasAnalysis::getLocation(const AtomicCmpXchgInst *CXI) {
+  return Location(CXI->getPointerOperand(),
+                  getTypeStoreSize(CXI->getCompareOperand()->getType()),
+                  CXI->getMetadata(LLVMContext::MD_tbaa));
+}
+
+AliasAnalysis::Location
+AliasAnalysis::getLocation(const AtomicRMWInst *RMWI) {
+  return Location(RMWI->getPointerOperand(),
+                  getTypeStoreSize(RMWI->getValOperand()->getType()),
+                  RMWI->getMetadata(LLVMContext::MD_tbaa));
+}
 
 AliasAnalysis::Location 
 AliasAnalysis::getLocationForSource(const MemTransferInst *MTI) {
@@ -317,6 +330,33 @@ AliasAnalysis::getModRefInfo(const VAArgInst *V, const Location &Loc) {
   return ModRef;
 }
 
+AliasAnalysis::ModRefResult
+AliasAnalysis::getModRefInfo(const AtomicCmpXchgInst *CX, const Location &Loc) {
+  // Acquire/Release cmpxchg has properties that matter for arbitrary addresses.
+  if (CX->getOrdering() > Monotonic)
+    return ModRef;
+
+  // If the cmpxchg address does not alias the location, it does not access it.
+  if (!alias(getLocation(CX), Loc))
+    return NoModRef;
+
+  return ModRef;
+}
+
+AliasAnalysis::ModRefResult
+AliasAnalysis::getModRefInfo(const AtomicRMWInst *RMW, const Location &Loc) {
+  // Acquire/Release atomicrmw has properties that matter for arbitrary addresses.
+  if (RMW->getOrdering() > Monotonic)
+    return ModRef;
+
+  // If the atomicrmw address does not alias the location, it does not access it.
+  if (!alias(getLocation(RMW), Loc))
+    return NoModRef;
+
+  return ModRef;
+}
+
+
 // AliasAnalysis destructor: DO NOT move this to the header file for
 // AliasAnalysis or else clients of the AliasAnalysis class may not depend on
 // the AliasAnalysis.o file in the current .a file, causing alias analysis
-- 
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