From f8bf116f808ecc6a9ca09cb761fe2a169e006b57 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 22 Feb 2006 23:55:00 +0000 Subject: [PATCH] Fix Regression/Transforms/LoopUnswitch/2006-02-22-UnswitchCrash.ll, which caused SPASS to fail building last night. We can't trivially unswitch a loop if the exit block has phi nodes in it, because we don't know which predecessor to use. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26320 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopUnswitch.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp index 61a043596d6..b0be443c116 100644 --- a/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -325,7 +325,9 @@ static bool IsTrivialUnswitchCondition(Loop *L, Value *Cond, Constant **Val = 0, } } - if (!LoopExitBB) + // If we didn't find a single unique LoopExit block, or if the loop exit block + // contains phi nodes, this isn't trivial. + if (!LoopExitBB || isa(LoopExitBB->begin())) return false; // Can't handle this. if (LoopExit) *LoopExit = LoopExitBB;