llvm-project/llvm/lib/CodeGen/FuncletLayout.cpp

60 lines
2.0 KiB
C++

//===-- FuncletLayout.cpp - Contiguously lay out funclets -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements basic block placement transformations which result in
// funclets being contiguous.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
using namespace llvm;
#define DEBUG_TYPE "funclet-layout"
namespace {
class FuncletLayout : public MachineFunctionPass {
public:
static char ID; // Pass identification, replacement for typeid
FuncletLayout() : MachineFunctionPass(ID) {
initializeFuncletLayoutPass(*PassRegistry::getPassRegistry());
}
bool runOnMachineFunction(MachineFunction &F) override;
MachineFunctionProperties getRequiredProperties() const override {
return MachineFunctionProperties().set(
MachineFunctionProperties::Property::NoVRegs);
}
};
}
char FuncletLayout::ID = 0;
char &llvm::FuncletLayoutID = FuncletLayout::ID;
INITIALIZE_PASS(FuncletLayout, "funclet-layout",
"Contiguously Lay Out Funclets", false, false)
bool FuncletLayout::runOnMachineFunction(MachineFunction &F) {
DenseMap<const MachineBasicBlock *, int> FuncletMembership =
getFuncletMembership(F);
if (FuncletMembership.empty())
return false;
F.sort([&](MachineBasicBlock &X, MachineBasicBlock &Y) {
auto FuncletX = FuncletMembership.find(&X);
auto FuncletY = FuncletMembership.find(&Y);
assert(FuncletX != FuncletMembership.end());
assert(FuncletY != FuncletMembership.end());
return FuncletX->second < FuncletY->second;
});
// Conservatively assume we changed something.
return true;
}