diff options
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
-rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 7ec31657ec..11cb25d0f9 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1446,14 +1446,12 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB) { if (Operator::getOpcode(CE) == Instruction::Select) return false; - // An unfolded ConstantExpr could end up getting expanded into - // Instructions. Don't speculate this and another instruction at - // the same time. - // FIXME: This is strange because provided we haven't already hit the cost - // of 1, this code will speculate an arbitrary number of complex constant - // expression PHI nodes. Also, this doesn't account for how complex the - // constant expression is. - if (SpeculationCost > 0) + // Account for the cost of an unfolded ConstantExpr which could end up + // getting expanded into Instructions. + // FIXME: This doesn't account for how many operations are combined in the + // constant expression. + ++SpeculationCost; + if (SpeculationCost > 1) return false; } |