From 4cf0dcfb44d9d308f2df48e2878c91297395179c Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Tue, 9 Nov 2010 20:17:38 +0000 Subject: [PATCH] Teach FunctionAttrs about the VAArg instruction. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118627 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/IPO/FunctionAttrs.cpp | 7 +++++++ .../TypeBasedAliasAnalysis/functionattrs.ll | 14 ++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp index fcdc5f18f16..8bdf5d75dad 100644 --- a/lib/Transforms/IPO/FunctionAttrs.cpp +++ b/lib/Transforms/IPO/FunctionAttrs.cpp @@ -195,6 +195,13 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) { if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) continue; } + } else if (VAArgInst *VI = dyn_cast(I)) { + // Ignore vaargs on local memory. + AliasAnalysis::Location Loc(VI->getPointerOperand(), + AliasAnalysis::UnknownSize, + VI->getMetadata(LLVMContext::MD_tbaa)); + if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) + continue; } // Any remaining instructions need to be taken seriously! Check if they diff --git a/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll b/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll index 5ef355fd93b..53cce0c94f7 100644 --- a/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll +++ b/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll @@ -55,6 +55,20 @@ define void @test2_no(i8* %p, i8* %q, i64 %n) nounwind { ret void } +; Similar to the others, va_arg only accesses memory through its operand. + +; CHECK: define i32 @test3_yes(i8* nocapture %p) nounwind readnone { +define i32 @test3_yes(i8* %p) nounwind { + %t = va_arg i8* %p, i32, !tbaa !1 + ret i32 %t +} + +; CHECK: define i32 @test3_no(i8* nocapture %p) nounwind { +define i32 @test3_no(i8* %p) nounwind { + %t = va_arg i8* %p, i32, !tbaa !2 + ret i32 %t +} + declare void @callee(i32* %p) nounwind declare void @llvm.memcpy.p0i8.p0i8.i64(i8*, i8*, i64, i32, i1) nounwind