Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.
Will be re-reverting again.
llvm-svn: 358552
GitOrigin-RevId: cee313d288a4faf0355d76fb6e0e927e211d08a5
diff --git a/test/Transforms/SimplifyCFG/PhiBlockMerge.ll b/test/Transforms/SimplifyCFG/PhiBlockMerge.ll
new file mode 100644
index 0000000..85b9870
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/PhiBlockMerge.ll
@@ -0,0 +1,29 @@
+; NOTE: Assertions have been autogenerated by update_test_checks.py
+; Test merging of blocks that only have PHI nodes in them
+;
+; RUN: opt < %s -simplifycfg -S | FileCheck %s
+;
+
+define i32 @test(i1 %a, i1 %b) {
+; CHECK-LABEL: @test(
+; CHECK: M:
+; CHECK-NEXT: [[DOT:%.*]] = select i1 %b, i32 0, i32 1
+; CHECK-NEXT: [[W:%.*]] = select i1 %a, i32 2, i32 [[DOT]]
+; CHECK-NEXT: [[R:%.*]] = add i32 [[W]], 1
+; CHECK-NEXT: ret i32 [[R]]
+;
+ br i1 %a, label %M, label %O
+O: ; preds = %0
+ br i1 %b, label %N, label %Q
+Q: ; preds = %O
+ br label %N
+N: ; preds = %Q, %O
+ ; This block should be foldable into M
+ %Wp = phi i32 [ 0, %O ], [ 1, %Q ] ; <i32> [#uses=1]
+ br label %M
+M: ; preds = %N, %0
+ %W = phi i32 [ %Wp, %N ], [ 2, %0 ] ; <i32> [#uses=1]
+ %R = add i32 %W, 1 ; <i32> [#uses=1]
+ ret i32 %R
+}
+
