[llvm-commits] [llvm] r83959 - in /llvm/trunk: lib/Analysis/BasicAliasAnalysis.cpp test/Analysis/BasicAA/2009-10-13-AtomicModRef.ll
Nick Lewycky
nicholas at mxc.ca
Tue Oct 13 00:48:39 PDT 2009
Author: nicholas
Date: Tue Oct 13 02:48:38 2009
New Revision: 83959
URL: http://llvm.org/viewvc/llvm-project?rev=83959&view=rev
Log:
Teach BasicAA a little something about the atomic intrinsics: they can only
modify through the pointer they're given.
Added:
llvm/trunk/test/Analysis/BasicAA/2009-10-13-AtomicModRef.ll
Modified:
llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
Modified: llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp?rev=83959&r1=83958&r2=83959&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp Tue Oct 13 02:48:38 2009
@@ -284,6 +284,27 @@
if (!passedAsArg)
return NoModRef;
}
+
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(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.
Added: llvm/trunk/test/Analysis/BasicAA/2009-10-13-AtomicModRef.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/BasicAA/2009-10-13-AtomicModRef.ll?rev=83959&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/BasicAA/2009-10-13-AtomicModRef.ll (added)
+++ llvm/trunk/test/Analysis/BasicAA/2009-10-13-AtomicModRef.ll Tue Oct 13 02:48:38 2009
@@ -0,0 +1,16 @@
+; RUN: opt -gvn -S < %s | FileCheck %s
+
+declare i8 @llvm.atomic.load.add.i8.p0i8(i8*, i8)
+
+define void @foo(i8* %ptr) {
+ %P = getelementptr i8* %ptr, i32 0
+ %Q = getelementptr i8* %ptr, i32 1
+; CHECK: getelementptr
+ %X = load i8* %P
+; CHECK: = load
+ %Y = call i8 @llvm.atomic.load.add.i8.p0i8(i8* %Q, i8 1)
+ %Z = load i8* %P
+; CHECK-NOT: = load
+ ret void
+; CHECK: ret void
+}
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