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author | Michael Kuperstein <mkuper@google.com> | 2017-03-16 21:07:48 +0000 |
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committer | Michael Kuperstein <mkuper@google.com> | 2017-03-16 21:07:48 +0000 |
commit | 2da2bfa088e9bf344a3ae7710dea518766cc730c (patch) | |
tree | 4215783100e213561426eda4df9d4531853a4c05 /llvm/test/Transforms/LoopUnroll | |
parent | 99de88d1f3f095ccf0d978a1d3c2b84147420353 (diff) | |
download | bcm5719-llvm-2da2bfa088e9bf344a3ae7710dea518766cc730c.tar.gz bcm5719-llvm-2da2bfa088e9bf344a3ae7710dea518766cc730c.zip |
[LoopUnroll] Don't peel loops where the latch isn't the exiting block
Peeling assumed this doesn't happen, but didn't check it.
This fixes PR32178.
Differential Revision: https://reviews.llvm.org/D30757
llvm-svn: 297993
Diffstat (limited to 'llvm/test/Transforms/LoopUnroll')
-rw-r--r-- | llvm/test/Transforms/LoopUnroll/peel-loop-irreducible.ll | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopUnroll/peel-loop-irreducible.ll b/llvm/test/Transforms/LoopUnroll/peel-loop-irreducible.ll new file mode 100644 index 00000000000..32a7a0732e1 --- /dev/null +++ b/llvm/test/Transforms/LoopUnroll/peel-loop-irreducible.ll @@ -0,0 +1,36 @@ +; RUN: opt < %s -S -loop-unroll -unroll-force-peel-count=1 | FileCheck %s + +; Check we don't peel loops where the latch is not the exiting block. +; CHECK-LABEL: @invariant_backedge_irreducible +; CHECK: entry: +; CHECK: br label %header +; CHECK-NOT: peel +; CHECK: header: +; CHECK: br i1 {{.*}} label %latch, label %exiting +; CHECK: latch: +; CHECK: br i1 {{.*}} label %header, label %exiting +; CHECK: exiting: +; CHECK: br i1 {{.*}} label %latch, label %exit + +define i32 @invariant_backedge_irreducible(i32 %a, i32 %b) { +entry: + br label %header + +header: + %i = phi i32 [ 0, %entry ], [ %inc, %latch ] + %cmp.phi = phi i1 [ false, %entry ], [ %cmp, %latch ] + br i1 %cmp.phi, label %latch, label %exiting + +latch: + %inc = add i32 %i, 1 + %cmp = icmp slt i32 %i, 1000 + br i1 %cmp, label %header, label %exiting + +exiting: + %cmp.exiting = phi i1 [ %cmp.phi, %header ], [ %cmp, %latch ] + br i1 %cmp.exiting, label %latch, label %exit + +exit: + ret i32 0 +} + |