Fully invalidate cached results when a prior query's size or

type is insufficient for, or incompatible with, the current query.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118721 91177308-0d34-0410-b5e6-96231b3b80d8

test/Analysis/TypeBasedAliasAnalysis/gvn-nonlocal-type-mismatch.ll

@@ -0,0 +1,91 @@
+; RUN: opt -enable-tbaa -tbaa -basicaa -gvn -S < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64"
+
+; GVN should ignore the store to p1 to see that the load from p is
+; fully redundant.
+
+; CHECK: @yes
+; CHECK: if.then:
+; CHECK-NEXT: store i32 0, i32* %q
+; CHECK-NEXT: ret void
+
+define void @yes(i1 %c, i32* %p, i32* %p1, i32* %q) nounwind {
+entry:
+  store i32 0, i32* %p, !tbaa !1
+  store i32 1, i32* %p1, !tbaa !2
+  br i1 %c, label %if.else, label %if.then
+
+if.then:
+  %t = load i32* %p, !tbaa !1
+  store i32 %t, i32* %q
+  ret void
+
+if.else:
+  ret void
+}
+
+; GVN should ignore the store to p1 to see that the first load from p is
+; fully redundant. However, the second load uses a different type. Theoretically
+; the other type could be unified with the first type, however for now, GVN
+; should just be conservative.
+
+; CHECK: @watch_out_for_type_change
+; CHECK: if.then:
+; CHECK:   %t = load i32* %p
+; CHECK:   store i32 %t, i32* %q
+; CHECK:   ret void
+; CHECK: if.else:
+; CHECK:   %u = load i32* %p
+; CHECK:   store i32 %u, i32* %q
+
+define void @watch_out_for_type_change(i1 %c, i32* %p, i32* %p1, i32* %q) nounwind {
+entry:
+  store i32 0, i32* %p, !tbaa !1
+  store i32 1, i32* %p1, !tbaa !2
+  br i1 %c, label %if.else, label %if.then
+
+if.then:
+  %t = load i32* %p, !tbaa !4
+  store i32 %t, i32* %q
+  ret void
+
+if.else:
+  %u = load i32* %p, !tbaa !3
+  store i32 %u, i32* %q
+  ret void
+}
+
+; As before, but the types are swapped. This time GVN does managed to
+; eliminate one of the loads before noticing the type mismatch.
+
+; CHECK: @watch_out_for_another_type_change
+; CHECK: if.then:
+; CHECK:   %t = load i32* %p
+; CHECK:   store i32 %t, i32* %q
+; CHECK:   ret void
+; CHECK: if.else:
+; CHECK:   store i32 0, i32* %q
+
+define void @watch_out_for_another_type_change(i1 %c, i32* %p, i32* %p1, i32* %q) nounwind {
+entry:
+  store i32 0, i32* %p, !tbaa !1
+  store i32 1, i32* %p1, !tbaa !2
+  br i1 %c, label %if.else, label %if.then
+
+if.then:
+  %t = load i32* %p, !tbaa !3
+  store i32 %t, i32* %q
+  ret void
+
+if.else:
+  %u = load i32* %p, !tbaa !4
+  store i32 %u, i32* %q
+  ret void
+}
+
+!0 = metadata !{}
+!1 = metadata !{metadata !"red", metadata !0}
+!2 = metadata !{metadata !"blu", metadata !0}
+!3 = metadata !{metadata !"outer space"}
+!4 = metadata !{metadata !"brick red", metadata !1}