X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FUnifyFunctionExitNodes.cpp;h=0c1eda7c0cc82922b7f14e4dadd26b59c9bd61d2;hb=eb516e7f0aa3223eab7967f4c0f8132d82efd841;hp=064bba5dddd0f36de4596f3bc4ce6940c4f82271;hpb=108e4ab159b59a616b0868e396dc7ddc1fb48616;p=oota-llvm.git diff --git a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp index 064bba5dddd..0c1eda7c0cc 100644 --- a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp +++ b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp @@ -1,10 +1,10 @@ //===- UnifyFunctionExitNodes.cpp - Make all functions have a single exit -===// -// +// // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. -// +// //===----------------------------------------------------------------------===// // // This pass is used to ensure that functions have at most one return @@ -18,8 +18,7 @@ #include "llvm/Transforms/Scalar.h" #include "llvm/BasicBlock.h" #include "llvm/Function.h" -#include "llvm/iTerminators.h" -#include "llvm/iPHINode.h" +#include "llvm/Instructions.h" #include "llvm/Type.h" using namespace llvm; @@ -47,13 +46,16 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) { // std::vector ReturningBlocks; std::vector UnwindingBlocks; + std::vector UnreachableBlocks; for(Function::iterator I = F.begin(), E = F.end(); I != E; ++I) if (isa(I->getTerminator())) ReturningBlocks.push_back(I); else if (isa(I->getTerminator())) UnwindingBlocks.push_back(I); + else if (isa(I->getTerminator())) + UnreachableBlocks.push_back(I); - // Handle unwinding blocks first... + // Handle unwinding blocks first. if (UnwindingBlocks.empty()) { UnwindBlock = 0; } else if (UnwindingBlocks.size() == 1) { @@ -62,15 +64,32 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) { UnwindBlock = new BasicBlock("UnifiedUnwindBlock", &F); new UnwindInst(UnwindBlock); - for (std::vector::iterator I = UnwindingBlocks.begin(), + for (std::vector::iterator I = UnwindingBlocks.begin(), E = UnwindingBlocks.end(); I != E; ++I) { BasicBlock *BB = *I; - BB->getInstList().pop_back(); // Remove the return insn - new BranchInst(UnwindBlock, 0, 0, BB); + BB->getInstList().pop_back(); // Remove the unwind insn + new BranchInst(UnwindBlock, BB); + } + } + + // Then unreachable blocks. + if (UnreachableBlocks.empty()) { + UnreachableBlock = 0; + } else if (UnreachableBlocks.size() == 1) { + UnreachableBlock = UnreachableBlocks.front(); + } else { + UnreachableBlock = new BasicBlock("UnifiedUnreachableBlock", &F); + new UnreachableInst(UnreachableBlock); + + for (std::vector::iterator I = UnreachableBlocks.begin(), + E = UnreachableBlocks.end(); I != E; ++I) { + BasicBlock *BB = *I; + BB->getInstList().pop_back(); // Remove the unreachable inst. + new BranchInst(UnreachableBlock, BB); } } - // Now handle return blocks... + // Now handle return blocks. if (ReturningBlocks.empty()) { ReturnBlock = 0; return false; // No blocks return @@ -80,7 +99,7 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) { } // Otherwise, we need to insert a new basic block into the function, add a PHI - // node (if the function returns a value), and convert all of the return + // node (if the function returns a value), and convert all of the return // instructions into unconditional branches. // BasicBlock *NewRetBlock = new BasicBlock("UnifiedReturnBlock", &F); @@ -96,7 +115,7 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) { // Loop over all of the blocks, replacing the return instruction with an // unconditional branch. // - for (std::vector::iterator I = ReturningBlocks.begin(), + for (std::vector::iterator I = ReturningBlocks.begin(), E = ReturningBlocks.end(); I != E; ++I) { BasicBlock *BB = *I;