llvm-project/llvm/lib/CodeGen/LiveRangeUtils.h

62 lines
2.1 KiB
C++

//===-- LiveRangeUtils.h - Live Range modification utilities ----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// This file contains helper functions to modify live ranges.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_CODEGEN_LIVERANGEUTILS_H
#define LLVM_LIB_CODEGEN_LIVERANGEUTILS_H
#include "llvm/CodeGen/LiveInterval.h"
namespace llvm {
/// Helper function that distributes live range value numbers and the
/// corresponding segments of a primary live range \p LR to a list of newly
/// created live ranges \p SplitLRs. \p VNIClasses maps each value number in \p
/// LR to 0 meaning it should stay or to 1..N meaning it should go to a specific
/// live range in the \p SplitLRs array.
template<typename LiveRangeT, typename EqClassesT>
static void DistributeRange(LiveRangeT &LR, LiveRangeT *SplitLRs[],
EqClassesT VNIClasses) {
// Move segments to new intervals.
typename LiveRangeT::iterator J = LR.begin(), E = LR.end();
while (J != E && VNIClasses[J->valno->id] == 0)
++J;
for (typename LiveRangeT::iterator I = J; I != E; ++I) {
if (unsigned eq = VNIClasses[I->valno->id]) {
assert((SplitLRs[eq-1]->empty() || SplitLRs[eq-1]->expiredAt(I->start)) &&
"New intervals should be empty");
SplitLRs[eq-1]->segments.push_back(*I);
} else
*J++ = *I;
}
LR.segments.erase(J, E);
// Transfer VNInfos to their new owners and renumber them.
unsigned j = 0, e = LR.getNumValNums();
while (j != e && VNIClasses[j] == 0)
++j;
for (unsigned i = j; i != e; ++i) {
VNInfo *VNI = LR.getValNumInfo(i);
if (unsigned eq = VNIClasses[i]) {
VNI->id = SplitLRs[eq-1]->getNumValNums();
SplitLRs[eq-1]->valnos.push_back(VNI);
} else {
VNI->id = j;
LR.valnos[j++] = VNI;
}
}
LR.valnos.resize(j);
}
} // End llvm namespace
#endif