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| author | David Majnemer <david.majnemer@gmail.com> | 2014-09-03 23:03:18 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2014-09-03 23:03:18 +0000 |
| commit | c6ab01eccae05aee4bae81a875a6eb88907247c5 (patch) | |
| tree | bd4c16b8d55d58e1697cf55275b6c8d167790348 /llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll | |
| parent | fb5d6852c6038455dca4da196558803005ced0d1 (diff) | |
| download | bcm5719-llvm-c6ab01eccae05aee4bae81a875a6eb88907247c5.tar.gz bcm5719-llvm-c6ab01eccae05aee4bae81a875a6eb88907247c5.zip | |
IndVarSimplify: Don't let LFTR compare against a poison value
LinearFunctionTestReplace tries to use the *next* indvar to compare
against when possible. However, it may be the case that the calculation
for the next indvar has NUW/NSW flags and that it may only be safely
used inside the loop. Using it in a comparison to calculate the exit
condition could result in observing poison.
This fixes PR20680.
Differential Revision: http://reviews.llvm.org/D5174
llvm-svn: 217102
Diffstat (limited to 'llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll')
| -rw-r--r-- | llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll b/llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll index 4736f857bcc..eeffd0f5502 100644 --- a/llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll +++ b/llvm/test/Transforms/IndVarSimplify/lftr-extend-const.ll @@ -2,7 +2,7 @@ ; CHECK-LABEL: @foo( ; CHECK-NOT: %lftr.wideiv = trunc i32 %indvars.iv.next to i16 -; CHECK: %exitcond = icmp ne i32 %indvars.iv.next, 512 +; CHECK: %exitcond = icmp ne i32 %indvars.iv, 511 define void @foo() #0 { entry: br label %for.body @@ -21,7 +21,7 @@ for.end: ; preds = %for.body ; Check that post-incrementing the backedge taken count does not overflow. ; CHECK-LABEL: @postinc( -; CHECK: icmp eq i32 %indvars.iv.next, 256 +; CHECK: icmp eq i32 %indvars.iv, 255 define i32 @postinc() #0 { entry: br label %do.body |
