From e2782c7614630e2c5eae5677388784f9b2ae8396 Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Tue, 13 Oct 2009 07:48:38 +0000 Subject: Teach BasicAA a little something about the atomic intrinsics: they can only modify through the pointer they're given. llvm-svn: 83959 --- llvm/lib/Analysis/BasicAliasAnalysis.cpp | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'llvm/lib/Analysis/BasicAliasAnalysis.cpp') diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp index 5fa87ff3655..2e3c75de506 100644 --- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp +++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp @@ -284,6 +284,27 @@ BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) { if (!passedAsArg) return NoModRef; } + + if (IntrinsicInst *II = dyn_cast(CS.getInstruction())) { + switch (II->getIntrinsicID()) { + default: break; + case Intrinsic::atomic_cmp_swap: + case Intrinsic::atomic_swap: + case Intrinsic::atomic_load_add: + case Intrinsic::atomic_load_sub: + case Intrinsic::atomic_load_and: + case Intrinsic::atomic_load_nand: + case Intrinsic::atomic_load_or: + case Intrinsic::atomic_load_xor: + case Intrinsic::atomic_load_max: + case Intrinsic::atomic_load_min: + case Intrinsic::atomic_load_umax: + case Intrinsic::atomic_load_umin: + if (alias(II->getOperand(1), Size, P, Size) == NoAlias) + return NoModRef; + break; + } + } } // The AliasAnalysis base class has some smarts, lets use them. -- cgit v1.2.3