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| author | Tom Stellard <thomas.stellard@amd.com> | 2016-07-14 15:50:27 +0000 |
|---|---|---|
| committer | Tom Stellard <thomas.stellard@amd.com> | 2016-07-14 15:50:27 +0000 |
| commit | 1b5cf6217e8e829bd6af02dad408d30f553897b5 (patch) | |
| tree | e8d4e44a8d84d53485409d3176c4934f756fa7a4 | |
| parent | 5bb284226be4556957832fbfed38700d06129639 (diff) | |
| download | bcm5719-llvm-1b5cf6217e8e829bd6af02dad408d30f553897b5.tar.gz bcm5719-llvm-1b5cf6217e8e829bd6af02dad408d30f553897b5.zip | |
GlobalsAA: Functions with the argmemonly attribute won't read arbitrary globals
Summary:
In preparation for changing GlobalsAA to stop assuming that intrinsics
can't read arbitrary globals, we need to make sure GlobalsAA is querying
function attributes rather than relying on this assumption.
This patch was inspired by: http://reviews.llvm.org/D20206
Reviewers: jmolloy, hfinkel
Subscribers: eli.friedman, llvm-commits
Differential Revision: https://reviews.llvm.org/D21318
llvm-svn: 275433
| -rw-r--r-- | llvm/lib/Analysis/GlobalsModRef.cpp | 2 | ||||
| -rw-r--r-- | llvm/test/Analysis/GlobalsModRef/func-memattributes.ll | 31 |
2 files changed, 32 insertions, 1 deletions
diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp index 0dc00789f0f..a7d1e048e13 100644 --- a/llvm/lib/Analysis/GlobalsModRef.cpp +++ b/llvm/lib/Analysis/GlobalsModRef.cpp @@ -498,7 +498,7 @@ void GlobalsAAResult::AnalyzeCallGraph(CallGraph &CG, Module &M) { // Can't do better than that! } else if (F->onlyReadsMemory()) { FI.addModRefInfo(MRI_Ref); - if (!F->isIntrinsic()) + if (!F->isIntrinsic() && !F->onlyAccessesArgMemory()) // This function might call back into the module and read a global - // consider every global as possibly being read by this function. FI.setMayReadAnyGlobal(); diff --git a/llvm/test/Analysis/GlobalsModRef/func-memattributes.ll b/llvm/test/Analysis/GlobalsModRef/func-memattributes.ll new file mode 100644 index 00000000000..5494512592e --- /dev/null +++ b/llvm/test/Analysis/GlobalsModRef/func-memattributes.ll @@ -0,0 +1,31 @@ +; RUN: opt < %s -disable-basicaa -globals-aa -dse -S | FileCheck %s + +@X = internal global i32 4 + +define void @test0() { +; CHECK-LABEL: @test0 +; CHECK: store i32 0, i32* @X +; CHECK-NEXT: call void @func_readonly() #0 +; CHECK-NEXT: store i32 1, i32* @X + store i32 0, i32* @X + call void @func_readonly() #0 + store i32 1, i32* @X + ret void +} + +define void @test1() { +; CHECK-LABEL: @test1 +; CHECK-NOT: store +; CHECK: call void @func_read_argmem_only() #1 +; CHECK-NEXT: store i32 3, i32* @X + store i32 2, i32* @X + call void @func_read_argmem_only() #1 + store i32 3, i32* @X + ret void +} + +declare void @func_readonly() #0 +declare void @func_read_argmem_only() #1 + +attributes #0 = { readonly } +attributes #1 = { readonly argmemonly } |
