From 0ed7f42c1b6e6dab8b531d7f2fa45ed2fe310849 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 29 Sep 2004 05:43:32 +0000 Subject: Do not insert trivially dead select instructions, which allows us to potentially fold more in one pass. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16583 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/SimplifyCFG.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index baa737e..77d3fe3 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -753,10 +753,19 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { FalseSucc->removePredecessor(BI->getParent()); // Insert a new select instruction. - Value *NewRetVal = new SelectInst(BI->getCondition(), TrueValue, - FalseValue, "retval", BI); + Value *NewRetVal; + Value *BrCond = BI->getCondition(); + if (TrueValue != FalseValue) + NewRetVal = new SelectInst(BrCond, TrueValue, + FalseValue, "retval", BI); + else + NewRetVal = TrueValue; + new ReturnInst(NewRetVal, BI); BI->getParent()->getInstList().erase(BI); + if (BrCond->use_empty()) + if (Instruction *BrCondI = dyn_cast(BrCond)) + BrCondI->getParent()->getInstList().erase(BrCondI); return true; } } -- cgit v1.1