From 864737bf9e208566bbecb81dda9cce5245fa2bcf Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 11 Dec 2004 05:32:19 +0000 Subject: [PATCH] Do not delete the entry block to a function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18795 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SCCP.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp index 9a8d26bb7b8..7682e5a9e18 100644 --- a/lib/Transforms/Scalar/SCCP.cpp +++ b/lib/Transforms/Scalar/SCCP.cpp @@ -1178,7 +1178,6 @@ bool IPSCCP::runOnModule(Module &M) { if (!ExecutableBBs.count(BB)) { DEBUG(std::cerr << " BasicBlock Dead:" << *BB); ++IPNumDeadBlocks; - BlocksToErase.push_back(BB); // Delete the instructions backwards, as it has a reduced likelihood of // having to update as many def-use and use-def chains. @@ -1206,6 +1205,11 @@ bool IPSCCP::runOnModule(Module &M) { TI->replaceAllUsesWith(UndefValue::get(TI->getType())); BB->getInstList().erase(TI); + if (&*BB != &F->front()) + BlocksToErase.push_back(BB); + else + new UnreachableInst(BB); + } else { for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) { Instruction *Inst = BI++;