llvm/lib/CodeGen/LiveRangeUtils.h
Matthias Braun 1cd242fe11 CodeGen: Refactor renameDisconnectedComponents() as a pass
Refactor LiveIntervals::renameDisconnectedComponents() to be a pass.
Also change the name to "RenameIndependentSubregs":

- renameDisconnectedComponents() worked on a MachineFunction at a time
  so it is a natural candidate for a machine function pass.

- The algorithm is testable with a .mir test now.

- This also fixes a problem where the lazy renaming as part of the
  MachineScheduler introduced IMPLICIT_DEF instructions after the number
  of a nodes in a region were counted leading to a mismatch.

Differential Revision: http://reviews.llvm.org/D20507

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271345 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-31 22:38:06 +00:00

63 lines
2.1 KiB
C++

//===-- LiveRangeUtils.h - Live Range modification utilities ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// 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 master 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