[PATCH] D21318: GlobalsAA: Functions with the argmemonly attribute won't read arbitrary globals

[Tom Stellard via llvm-commits]

tstellarAMD updated this revision to Diff 60785.
tstellarAMD added a comment.

Simplify the tests cases.


http://reviews.llvm.org/D21318

Files:
  lib/Analysis/GlobalsModRef.cpp
  test/Analysis/GlobalsModRef/func-memattributes.ll

Index: test/Analysis/GlobalsModRef/func-memattributes.ll
===================================================================
--- /dev/null
+++ test/Analysis/GlobalsModRef/func-memattributes.ll
@@ -0,0 +1,31 @@
+; RUN: opt < %s -basicaa -globals-aa -dse -S | FileCheck %s
+
+ at 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 }
Index: lib/Analysis/GlobalsModRef.cpp
===================================================================
--- lib/Analysis/GlobalsModRef.cpp
+++ lib/Analysis/GlobalsModRef.cpp
@@ -498,7 +498,7 @@
           // 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();


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