From a998735def5f04459fa6cbeaaffbb42f1a1dec5c Mon Sep 17 00:00:00 2001
From: Kevin Qin <Kevin.Qin@arm.com>
Date: Mon, 9 Mar 2015 06:14:07 +0000
Subject: Run LICM pass after loop unrolling pass.

Runtime unrollng will introduce a runtime check in loop prologue.
If the unrolled loop is a inner loop, then the proglogue will be inside
the outer loop. LICM pass can help to promote the runtime check out if
the checked value is loop invariant.

llvm-svn: 231630
---
 llvm/test/Transforms/LoopUnroll/runtime-loop4.ll | 43 ++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 llvm/test/Transforms/LoopUnroll/runtime-loop4.ll

(limited to 'llvm/test/Transforms/LoopUnroll/runtime-loop4.ll')

diff --git a/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll b/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll
new file mode 100644
index 00000000000..9be0ffd23d3
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/runtime-loop4.ll
@@ -0,0 +1,43 @@
+; RUN: opt < %s -S -O2 -unroll-runtime=true | FileCheck %s
+
+; Check runtime unrolling prologue can be promoted by LICM pass.
+
+; CHECK: entry:
+; CHECK: %xtraiter
+; CHECK: %lcmp.mod
+; CHECK: loop1:
+; CHECK: br i1 %lcmp.mod
+; CHECK: loop2.prol:
+
+define void @unroll(i32 %iter, i32* %addr1, i32* %addr2) nounwind {
+entry:
+  br label %loop1
+
+loop1:
+  %iv1 = phi i32 [ 0, %entry ], [ %inc1, %loop1.latch ]
+  %offset1 = getelementptr i32, i32* %addr1, i32 %iv1
+  store i32 %iv1, i32* %offset1, align 4
+  br label %loop2.header
+
+loop2.header:
+  br label %loop2
+
+loop2:
+  %iv2 = phi i32 [ 0, %loop2.header ], [ %inc2, %loop2 ]
+  %offset2 = getelementptr i32, i32* %addr2, i32 %iv2
+  store i32 %iv2, i32* %offset2, align 4
+  %inc2 = add i32 %iv2, 1
+  %exitcnd2 = icmp uge i32 %inc2, %iter
+  br i1 %exitcnd2, label %exit2, label %loop2
+
+exit2:
+  br label %loop1.latch
+
+loop1.latch:
+  %inc1 = add i32 %iv1, 1
+  %exitcnd1 = icmp uge i32 %inc1, 1024
+  br i1 %exitcnd1, label %exit, label %loop1
+
+exit:
+  ret void
+}
-- 
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