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| author | David Majnemer <david.majnemer@gmail.com> | 2013-06-03 20:43:12 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2013-06-03 20:43:12 +0000 |
| commit | 3931bdb788774e33dd623d6b9142ae69542c33aa (patch) | |
| tree | c9fa7476a4a2bae4cdd7af18d4f87ea38d558c9e /test | |
| parent | 404fa7257fae8e4252cd4d01017e97ab6062ab27 (diff) | |
| download | external_llvm-3931bdb788774e33dd623d6b9142ae69542c33aa.zip external_llvm-3931bdb788774e33dd623d6b9142ae69542c33aa.tar.gz external_llvm-3931bdb788774e33dd623d6b9142ae69542c33aa.tar.bz2 | |
SimplifyCFG: Do not transform PHI to select if doing so would be unsafe
PR16069 is an interesting case where an incoming value to a PHI is a
trap value while also being a 'ConstantExpr'.
We do not consider this case when performing the 'HoistThenElseCodeToIf'
optimization.
Instead, make our modifications more conservative if we detect that we
cannot transform the PHI to a select.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183152 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Transforms/SimplifyCFG/PR16069.ll | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/test/Transforms/SimplifyCFG/PR16069.ll b/test/Transforms/SimplifyCFG/PR16069.ll new file mode 100644 index 0000000..4e9f896 --- /dev/null +++ b/test/Transforms/SimplifyCFG/PR16069.ll @@ -0,0 +1,14 @@ +; RUN: opt < %s -simplifycfg -S | FileCheck %s + +; CHECK-NOT: select +@b = extern_weak global i32 +define i32 @foo(i1 %y) { + br i1 %y, label %bb1, label %bb2 +bb1: + br label %bb3 +bb2: + br label %bb3 +bb3: + %cond.i = phi i32 [ 0, %bb1 ], [ srem (i32 1, i32 zext (i1 icmp eq (i32* @b, i32* null) to i32)), %bb2 ] + ret i32 %cond.i +} |