Revert "Temporarily Revert "Add basic loop fusion pass.""

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

1 files changed, 36 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopSimplify/2003-12-10-ExitBlocksProblem.ll b/llvm/test/Transforms/LoopSimplify/2003-12-10-ExitBlocksProblem.ll
new file mode 100644
index 00000000000..32b632220d3
--- /dev/null
+++ b/llvm/test/Transforms/LoopSimplify/2003-12-10-ExitBlocksProblem.ll
@@ -0,0 +1,36 @@
+; LoopSimplify is breaking LICM on this testcase because the exit blocks from
+; the loop are reachable from more than just the exit nodes: the exit blocks
+; have predecessors from outside of the loop!
+;
+; This is distilled from a monsterous crafty example.
+
+; RUN: opt < %s -licm -disable-output
+
+
+@G = weak global i32 0		; <i32*> [#uses=7]
+
+define i32 @main() {
+entry:
+	store i32 123, i32* @G
+	br label %loopentry.i
+loopentry.i:		; preds = %endif.1.i, %entry
+	%tmp.0.i = load i32, i32* @G		; <i32> [#uses=1]
+	%tmp.1.i = icmp eq i32 %tmp.0.i, 123		; <i1> [#uses=1]
+	br i1 %tmp.1.i, label %Out.i, label %endif.0.i
+endif.0.i:		; preds = %loopentry.i
+	%tmp.3.i = load i32, i32* @G		; <i32> [#uses=1]
+	%tmp.4.i = icmp eq i32 %tmp.3.i, 126		; <i1> [#uses=1]
+	br i1 %tmp.4.i, label %ExitBlock.i, label %endif.1.i
+endif.1.i:		; preds = %endif.0.i
+	%tmp.6.i = load i32, i32* @G		; <i32> [#uses=1]
+	%inc.i = add i32 %tmp.6.i, 1		; <i32> [#uses=1]
+	store i32 %inc.i, i32* @G
+	br label %loopentry.i
+Out.i:		; preds = %loopentry.i
+	store i32 0, i32* @G
+	br label %ExitBlock.i
+ExitBlock.i:		; preds = %Out.i, %endif.0.i
+	%tmp.7.i = load i32, i32* @G		; <i32> [#uses=1]
+	ret i32 %tmp.7.i
+}
+