[PATCH] D16670: [ScopedNoAliasAA] Make test basic.ll less confusing

[Adam Nemet via llvm-commits]

anemet created this revision.
anemet added reviewers: hfinkel, reames.
anemet added a subscriber: llvm-commits.

This testcase had me confused.  It made me believe that you can use
alias scopes and alias scopes list interchangeably with alias.scope and
noalias.  Both langref and the other testcase use scope lists so I went
looking.

Turns out using scope directly only happens to work by chance.  When
ScopedNoAliasAAResult::mayAliasInScopes traverses this as a scope list:

!1 = !{!1, !0, !"some scope"}

, the first entry is in fact a scope but only because the scope is
happened to be defined self-referentially to make it unique globally.

The remaining elements in the tuple (!0, !"some scope") are considered
as scopes but AliasScopeNode::getDomain will just bail on those without
any error.

This change avoids this ambiguity in the test but I've also been
wondering if we should issue some sort of a diagnostics.

http://reviews.llvm.org/D16670

Files:
  test/Analysis/ScopedNoAliasAA/basic.ll

Index: test/Analysis/ScopedNoAliasAA/basic.ll
===================================================================
--- test/Analysis/ScopedNoAliasAA/basic.ll
+++ test/Analysis/ScopedNoAliasAA/basic.ll
@@ -5,9 +5,9 @@
 define void @foo1(float* nocapture %a, float* nocapture readonly %c) #0 {
 entry:
 ; CHECK-LABEL: Function: foo1
-  %0 = load float, float* %c, align 4, !alias.scope !1
+  %0 = load float, float* %c, align 4, !alias.scope !2
   %arrayidx.i = getelementptr inbounds float, float* %a, i64 5
-  store float %0, float* %arrayidx.i, align 4, !noalias !1
+  store float %0, float* %arrayidx.i, align 4, !noalias !2
   %1 = load float, float* %c, align 4
   %arrayidx = getelementptr inbounds float, float* %a, i64 7
   store float %1, float* %arrayidx, align 4
@@ -24,4 +24,4 @@
 
 !0 = !{!0, !"some domain"}
 !1 = !{!1, !0, !"some scope"}
-
+!2 = !{!1}


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