llvm/tools/llvm-exegesis/lib/RegisterAliasing.cpp

   1 //===-- RegisterAliasing.cpp ------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "RegisterAliasing.h"
  10
  11 namespace llvm {
  12 namespace exegesis {
  13
  14 BitVector getAliasedBits(const MCRegisterInfo &RegInfo,
  15                          const BitVector &SourceBits) {
  16   BitVector AliasedBits(RegInfo.getNumRegs());
  17   for (const size_t PhysReg : SourceBits.set_bits()) {
  18     using RegAliasItr = MCRegAliasIterator;
  19     for (auto Itr = RegAliasItr(PhysReg, &RegInfo, true); Itr.isValid();
  20          ++Itr) {
  21       AliasedBits.set(*Itr);
  22     }
  23   }
  24   return AliasedBits;
  25 }
  26
  27 RegisterAliasingTracker::RegisterAliasingTracker(const MCRegisterInfo &RegInfo)
  28     : SourceBits(RegInfo.getNumRegs()), AliasedBits(RegInfo.getNumRegs()),
  29       Origins(RegInfo.getNumRegs()) {}
  30
  31 RegisterAliasingTracker::RegisterAliasingTracker(
  32     const MCRegisterInfo &RegInfo, const BitVector &ReservedReg,
  33     const MCRegisterClass &RegClass)
  34     : RegisterAliasingTracker(RegInfo) {
  35   for (MCPhysReg PhysReg : RegClass)
  36     if (!ReservedReg[PhysReg]) // Removing reserved registers.
  37       SourceBits.set(PhysReg);
  38   FillOriginAndAliasedBits(RegInfo, SourceBits);
  39 }
  40
  41 RegisterAliasingTracker::RegisterAliasingTracker(const MCRegisterInfo &RegInfo,
  42                                                  const MCPhysReg PhysReg)
  43     : RegisterAliasingTracker(RegInfo) {
  44   SourceBits.set(PhysReg);
  45   FillOriginAndAliasedBits(RegInfo, SourceBits);
  46 }
  47
  48 void RegisterAliasingTracker::FillOriginAndAliasedBits(
  49     const MCRegisterInfo &RegInfo, const BitVector &SourceBits) {
  50   using RegAliasItr = MCRegAliasIterator;
  51   for (const size_t PhysReg : SourceBits.set_bits()) {
  52     for (auto Itr = RegAliasItr(PhysReg, &RegInfo, true); Itr.isValid();
  53          ++Itr) {
  54       AliasedBits.set(*Itr);
  55       Origins[*Itr] = PhysReg;
  56     }
  57   }
  58 }
  59
  60 RegisterAliasingTrackerCache::RegisterAliasingTrackerCache(
  61     const MCRegisterInfo &RegInfo, const BitVector &ReservedReg)
  62     : RegInfo(RegInfo), ReservedReg(ReservedReg),
  63       EmptyRegisters(RegInfo.getNumRegs()) {}
  64
  65 const RegisterAliasingTracker &
  66 RegisterAliasingTrackerCache::getRegister(MCPhysReg PhysReg) const {
  67   auto &Found = Registers[PhysReg];
  68   if (!Found)
  69     Found.reset(new RegisterAliasingTracker(RegInfo, PhysReg));
  70   return *Found;
  71 }
  72
  73 const RegisterAliasingTracker &
  74 RegisterAliasingTrackerCache::getRegisterClass(unsigned RegClassIndex) const {
  75   auto &Found = RegisterClasses[RegClassIndex];
  76   const auto &RegClass = RegInfo.getRegClass(RegClassIndex);
  77   if (!Found)
  78     Found.reset(new RegisterAliasingTracker(RegInfo, ReservedReg, RegClass));
  79   return *Found;
  80 }
  81
  82 std::string debugString(const MCRegisterInfo &RegInfo, const BitVector &Regs) {
  83   std::string Result;
  84   for (const unsigned Reg : Regs.set_bits()) {
  85     Result.append(RegInfo.getName(Reg));
  86     Result.push_back(' ');
  87   }
  88   return Result;
  89 }
  90
  91 } // namespace exegesis
  92 } // namespace llvm