Add a testcase to demonstrate the problem where phi translation is

ignored for clobbering partial-alias loads.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132633 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/GVN/phi-translate-partial-alias.ll b/test/Transforms/GVN/phi-translate-partial-alias.ll
new file mode 100644 (file)
index 0000000..47bec41
--- /dev/null
+++ b/test/Transforms/GVN/phi-translate-partial-alias.ll
@@ -0,0 +1,27 @@
+; RUN: opt -basicaa -gvn -S < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-f128:128:128-n8:16:32:64"
+
+; GVN shouldn't PRE the load around the loop backedge because it's
+; not actually redundant around the loop backedge, despite appearances
+; if phi-translation is ignored.
+
+; CHECK: define void @test0(i8* %begin)
+; CHECK: loop:
+; CHECK:   %l0 = load i8* %phi
+; CHECK:   call void @bar(i8 %l0)
+; CHECK:   %l1 = load i8* %phi
+define void @test0(i8* %begin) {
+entry:
+  br label %loop
+
+loop:
+  %phi = phi i8* [ %begin, %entry ], [ %next, %loop ]
+  %l0 = load i8* %phi
+  call void @bar(i8 %l0)
+  %l1 = load i8* %phi
+  %next = getelementptr inbounds i8* %phi, i8 %l1
+  br label %loop
+}
+
+declare void @bar(i8)