From c2fa6d64b4d3d48e1a639f351f252e778b26ba9c Mon Sep 17 00:00:00 2001
From: Chen Li <meloli87@gmail.com>
Date: Wed, 15 Jul 2015 22:41:13 +0000
Subject: [PATCH] [LoopUnswitch] Add an else clause to
IsTrivialUnswitchCondition() when checking HeaderTerm instruction type
Summary:
This is a trivial code change with no functionality effect.
When LoopUnswitch determines trivial unswitch condition, it checks whether the loop header's terminator instruction is a branch instruction or switch instruction since trivial unswitch condition can only apply to these two instruction types. The current code does not fail the check directly on other instruction types, but check the nullness of LoopExitBB variable instead. The added else clause makes the check fail immediately on other instruction types and makes the code more obvious.
Reviewers: reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11239
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242345 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/Transforms/Scalar/LoopUnswitch.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index cbc563bd899..ce167d1c657 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -641,7 +641,8 @@ bool LoopUnswitch::IsTrivialUnswitchCondition(Value *Cond, Constant **Val,
break;
}
}
- }
+ } else
+ return false;
// If we didn't find a single unique LoopExit block, or if the loop exit block
// contains phi nodes, this isn't trivial.
--
2.34.1