llvm-6502/lib/Target/NVPTX/NVPTXSplitBBatBar.cpp
Chandler Carruth 876ac60880 [Modules] Move InstIterator out of the Support library, where it had no
business.

This header includes Function and BasicBlock and directly uses the
interfaces of both classes. It has to do with the IR, it even has that
in the name. =] Put it in the library it belongs to.

This is one step toward making LLVM's Support library survive a C++
modules bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202814 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 10:30:26 +00:00

74 lines
2.3 KiB
C++

//===- NVPTXSplitBBatBar.cpp - Split BB at Barrier --*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// Split basic blocks so that a basic block that contains a barrier instruction
// only contains the barrier instruction.
//
//===----------------------------------------------------------------------===//
#include "NVPTXSplitBBatBar.h"
#include "NVPTXUtilities.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
using namespace llvm;
namespace llvm { FunctionPass *createSplitBBatBarPass(); }
char NVPTXSplitBBatBar::ID = 0;
bool NVPTXSplitBBatBar::runOnFunction(Function &F) {
SmallVector<Instruction *, 4> SplitPoints;
bool changed = false;
// Collect all the split points in SplitPoints
for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
BasicBlock::iterator IB = BI->begin();
BasicBlock::iterator II = IB;
BasicBlock::iterator IE = BI->end();
// Skit the first instruction. No splitting is needed at this
// point even if this is a bar.
while (II != IE) {
if (IntrinsicInst *inst = dyn_cast<IntrinsicInst>(II)) {
Intrinsic::ID id = inst->getIntrinsicID();
// If this is a barrier, split at this instruction
// and the next instruction.
if (llvm::isBarrierIntrinsic(id)) {
if (II != IB)
SplitPoints.push_back(II);
II++;
if ((II != IE) && (!II->isTerminator())) {
SplitPoints.push_back(II);
II++;
}
continue;
}
}
II++;
}
}
for (unsigned i = 0; i != SplitPoints.size(); i++) {
changed = true;
Instruction *inst = SplitPoints[i];
inst->getParent()->splitBasicBlock(inst, "bar_split");
}
return changed;
}
// This interface will most likely not be necessary, because this pass will
// not be invoked by the driver, but will be used as a prerequisite to
// another pass.
FunctionPass *llvm::createSplitBBatBarPass() { return new NVPTXSplitBBatBar(); }