From 81ebdcf7dd3c182f5fca352b59b336f79d5da23e Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Tue, 10 Nov 2009 21:14:05 +0000 Subject: Generalize lsr code that optimize loop to count down towards zero. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86715 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Transforms/LoopStrengthReduce/count-to-zero.ll | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 test/Transforms/LoopStrengthReduce/count-to-zero.ll (limited to 'test') diff --git a/test/Transforms/LoopStrengthReduce/count-to-zero.ll b/test/Transforms/LoopStrengthReduce/count-to-zero.ll new file mode 100644 index 0000000..8cc3b5c --- /dev/null +++ b/test/Transforms/LoopStrengthReduce/count-to-zero.ll @@ -0,0 +1,42 @@ +; RUN: opt < %s -loop-reduce -S | FileCheck %s +; rdar://7382068 + +define void @t(i32 %c) nounwind optsize { +entry: + br label %bb6 + +bb1: ; preds = %bb6 + %tmp = icmp eq i32 %c_addr.1, 20 ; [#uses=1] + br i1 %tmp, label %bb2, label %bb3 + +bb2: ; preds = %bb1 + %tmp1 = tail call i32 @f20(i32 %c_addr.1) nounwind ; [#uses=1] + br label %bb7 + +bb3: ; preds = %bb1 + %tmp2 = icmp slt i32 %c_addr.1, 10 ; [#uses=1] + %tmp3 = add nsw i32 %c_addr.1, 1 ; [#uses=1] + %tmp4 = add i32 %c_addr.1, -1 ; [#uses=1] + %c_addr.1.be = select i1 %tmp2, i32 %tmp3, i32 %tmp4 ; [#uses=1] + %indvar.next = add i32 %indvar, 1 ; [#uses=1] +; CHECK: sub i32 %lsr.iv, 1 + br label %bb6 + +bb6: ; preds = %bb3, %entry + %indvar = phi i32 [ %indvar.next, %bb3 ], [ 0, %entry ] ; [#uses=2] + %c_addr.1 = phi i32 [ %c_addr.1.be, %bb3 ], [ %c, %entry ] ; [#uses=7] + %tmp5 = icmp eq i32 %indvar, 9999 ; [#uses=1] +; CHECK: icmp eq i32 %lsr.iv, 0 + %tmp6 = icmp eq i32 %c_addr.1, 100 ; [#uses=1] + %or.cond = or i1 %tmp5, %tmp6 ; [#uses=1] + br i1 %or.cond, label %bb7, label %bb1 + +bb7: ; preds = %bb6, %bb2 + %c_addr.0 = phi i32 [ %tmp1, %bb2 ], [ %c_addr.1, %bb6 ] ; [#uses=1] + tail call void @bar(i32 %c_addr.0) nounwind + ret void +} + +declare i32 @f20(i32) + +declare void @bar(i32) -- cgit v1.1