From 513fae2db51c7d22ec1253e89939d27732b21a5e Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Wed, 20 May 2009 00:34:08 +0000 Subject: Suppress the IV reversal transformation in the case that the RHS of the comparison is defined inside the loop. This fixes a use-before-def problem, because the transformation puts a use of the RHS outside the loop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72149 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/LoopStrengthReduce/dont_reverse.ll | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 test/Transforms/LoopStrengthReduce/dont_reverse.ll (limited to 'test/Transforms') diff --git a/test/Transforms/LoopStrengthReduce/dont_reverse.ll b/test/Transforms/LoopStrengthReduce/dont_reverse.ll new file mode 100644 index 0000000..39eca6c --- /dev/null +++ b/test/Transforms/LoopStrengthReduce/dont_reverse.ll @@ -0,0 +1,21 @@ +; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis \ +; RUN: | grep {icmp eq i2 %lsr.iv.next, %xmp4344} + +; Don't reverse the iteration if the rhs of the compare is defined +; inside the loop. + +define void @Fill_Buffer() nounwind { +entry: + br label %bb8 + +bb8: + %indvar34 = phi i32 [ 0, %entry ], [ %indvar.next35, %bb8 ] + %indvar3451 = trunc i32 %indvar34 to i2 + %xmp4344 = xor i2 0, -1 + %xmp104 = icmp eq i2 %indvar3451, %xmp4344 + %indvar.next35 = add i32 %indvar34, 1 + br i1 %xmp104, label %bb10, label %bb8 + +bb10: + unreachable +} -- cgit v1.1