From 0fb7dcd48fd6580e3ebf35eafa952a9fe1cac8b2 Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Wed, 29 Jun 2011 05:25:47 +0000 Subject: Let simplify cfg simplify bb with only debug and lifetime intrinsics. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134057 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/Local.cpp | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'lib/Transforms/Utils/Local.cpp') diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index b1dd733ffe..0046945485 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -536,9 +536,9 @@ static bool CanPropagatePredecessorsForPHIs(BasicBlock *BB, BasicBlock *Succ) { /// TryToSimplifyUncondBranchFromEmptyBlock - BB is known to contain an /// unconditional branch, and contains no instructions other than PHI nodes, -/// potential debug intrinsics and the branch. If possible, eliminate BB by -/// rewriting all the predecessors to branch to the successor block and return -/// true. If we can't transform, return false. +/// potential side-effect free intrinsics and the branch. If possible, +/// eliminate BB by rewriting all the predecessors to branch to the successor +/// block and return true. If we can't transform, return false. bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB) { assert(BB != &BB->getParent()->getEntryBlock() && "TryToSimplifyUncondBranchFromEmptyBlock called on entry block!"); @@ -613,13 +613,15 @@ bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB) { } } - while (PHINode *PN = dyn_cast(&BB->front())) { - if (Succ->getSinglePredecessor()) { - // BB is the only predecessor of Succ, so Succ will end up with exactly - // the same predecessors BB had. - Succ->getInstList().splice(Succ->begin(), - BB->getInstList(), BB->begin()); - } else { + if (Succ->getSinglePredecessor()) { + // BB is the only predecessor of Succ, so Succ will end up with exactly + // the same predecessors BB had. + + // Copy over any phi, debug or lifetime instruction. + BB->getTerminator()->eraseFromParent(); + Succ->getInstList().splice(Succ->begin(), BB->getInstList()); + } else { + while (PHINode *PN = dyn_cast(&BB->front())) { // We explicitly check for such uses in CanPropagatePredecessorsForPHIs. assert(PN->use_empty() && "There shouldn't be any uses here!"); PN->eraseFromParent(); -- cgit v1.2.3-18-g5258