llvm/lib/Target/NVPTX/NVPTXAllocaHoisting.cpp
Matthias Braun fa5c5c7db3 CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses
Re-apply this patch, hopefully I will get away without any warnings
in the constructor now.

This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.

This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.

Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.

Differential Revision: http://reviews.llvm.org/D23736

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279602 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-24 01:52:46 +00:00

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2.1 KiB
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//===-- AllocaHoisting.cpp - Hoist allocas to the entry block --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Hoist the alloca instructions in the non-entry blocks to the entry blocks.
//
//===----------------------------------------------------------------------===//
#include "NVPTXAllocaHoisting.h"
#include "llvm/CodeGen/StackProtector.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
using namespace llvm;
namespace {
// Hoisting the alloca instructions in the non-entry blocks to the entry
// block.
class NVPTXAllocaHoisting : public FunctionPass {
public:
static char ID; // Pass ID
NVPTXAllocaHoisting() : FunctionPass(ID) {}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addPreserved<StackProtector>();
}
const char *getPassName() const override {
return "NVPTX specific alloca hoisting";
}
bool runOnFunction(Function &function) override;
};
} // namespace
bool NVPTXAllocaHoisting::runOnFunction(Function &function) {
bool functionModified = false;
Function::iterator I = function.begin();
TerminatorInst *firstTerminatorInst = (I++)->getTerminator();
for (Function::iterator E = function.end(); I != E; ++I) {
for (BasicBlock::iterator BI = I->begin(), BE = I->end(); BI != BE;) {
AllocaInst *allocaInst = dyn_cast<AllocaInst>(BI++);
if (allocaInst && isa<ConstantInt>(allocaInst->getArraySize())) {
allocaInst->moveBefore(firstTerminatorInst);
functionModified = true;
}
}
}
return functionModified;
}
char NVPTXAllocaHoisting::ID = 0;
namespace llvm {
void initializeNVPTXAllocaHoistingPass(PassRegistry &);
}
INITIALIZE_PASS(
NVPTXAllocaHoisting, "alloca-hoisting",
"Hoisting alloca instructions in non-entry blocks to the entry block",
false, false)
FunctionPass *llvm::createAllocaHoisting() { return new NVPTXAllocaHoisting; }