[GMR/OperandBundles] Teach getModRefBehavior about operand bundles
In general, memory restrictions on a called function (e.g. readnone)
cannot be transferred to a CallSite that has operand bundles. It is
possible to make this inference smarter, but lets fix the behavior to be
correct first.
llvm-svn: 260193
diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp
index 8338dcc..549b374 100644
--- a/llvm/lib/Analysis/GlobalsModRef.cpp
+++ b/llvm/lib/Analysis/GlobalsModRef.cpp
@@ -243,13 +243,14 @@
GlobalsAAResult::getModRefBehavior(ImmutableCallSite CS) {
FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
- if (const Function *F = CS.getCalledFunction())
- if (FunctionInfo *FI = getFunctionInfo(F)) {
- if (FI->getModRefInfo() == MRI_NoModRef)
- Min = FMRB_DoesNotAccessMemory;
- else if ((FI->getModRefInfo() & MRI_Mod) == 0)
- Min = FMRB_OnlyReadsMemory;
- }
+ if (!CS.hasOperandBundles())
+ if (const Function *F = CS.getCalledFunction())
+ if (FunctionInfo *FI = getFunctionInfo(F)) {
+ if (FI->getModRefInfo() == MRI_NoModRef)
+ Min = FMRB_DoesNotAccessMemory;
+ else if ((FI->getModRefInfo() & MRI_Mod) == 0)
+ Min = FMRB_OnlyReadsMemory;
+ }
return FunctionModRefBehavior(AAResultBase::getModRefBehavior(CS) & Min);
}
diff --git a/llvm/test/Feature/OperandBundles/pr26510.ll b/llvm/test/Feature/OperandBundles/pr26510.ll
new file mode 100644
index 0000000..d1d60b4
--- /dev/null
+++ b/llvm/test/Feature/OperandBundles/pr26510.ll
@@ -0,0 +1,27 @@
+; RUN: opt -S -globals-aa -functionattrs < %s | FileCheck %s
+; RUN: opt -S -O3 < %s | FileCheck %s
+
+; Apart from checking for the direct cause of the bug, we also check
+; if any problematic aliasing rules have accidentally snuck into -O3.
+;
+; Since the "abc" operand bundle is not a special operand bundle that
+; LLVM knows about, all of the stores and loads in @test below have to
+; stay.
+
+declare void @foo() readnone
+
+; CHECK-LABEL: define i8* @test(i8* %p) {
+; CHECK: %a = alloca i8*, align 8
+; CHECK: store i8* %p, i8** %a, align 8
+; CHECK: call void @foo() [ "abc"(i8** %a) ]
+; CHECK: %reload = load i8*, i8** %a, align 8
+; CHECK: ret i8* %reload
+; CHECK: }
+
+define i8* @test(i8* %p) {
+ %a = alloca i8*, align 8
+ store i8* %p, i8** %a, align 8
+ call void @foo() ["abc" (i8** %a)]
+ %reload = load i8*, i8** %a, align 8
+ ret i8* %reload
+}