tools/llvm-exegesis/lib/RegisterAliasing.cpp

   1 //===-- RegisterAliasingTracker.cpp -----------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "RegisterAliasing.h"
  11
  12 namespace llvm {
  13 namespace exegesis {
  14
  15 llvm::BitVector getAliasedBits(const llvm::MCRegisterInfo &RegInfo,
  16                                const llvm::BitVector &SourceBits) {
  17   llvm::BitVector AliasedBits(RegInfo.getNumRegs());
  18   for (const size_t PhysReg : SourceBits.set_bits()) {
  19     using RegAliasItr = llvm::MCRegAliasIterator;
  20     for (auto Itr = RegAliasItr(PhysReg, &RegInfo, true); Itr.isValid();
  21          ++Itr) {
  22       AliasedBits.set(*Itr);
  23     }
  24   }
  25   return AliasedBits;
  26 }
  27
  28 RegisterAliasingTracker::RegisterAliasingTracker(
  29     const llvm::MCRegisterInfo &RegInfo)
  30     : SourceBits(RegInfo.getNumRegs()), AliasedBits(RegInfo.getNumRegs()),
  31       Origins(RegInfo.getNumRegs()) {}
  32
  33 RegisterAliasingTracker::RegisterAliasingTracker(
  34     const llvm::MCRegisterInfo &RegInfo, const llvm::BitVector &ReservedReg,
  35     const llvm::MCRegisterClass &RegClass)
  36     : RegisterAliasingTracker(RegInfo) {
  37   for (llvm::MCPhysReg PhysReg : RegClass)
  38     if (!ReservedReg[PhysReg]) // Removing reserved registers.
  39       SourceBits.set(PhysReg);
  40   FillOriginAndAliasedBits(RegInfo, SourceBits);
  41 }
  42
  43 RegisterAliasingTracker::RegisterAliasingTracker(
  44     const llvm::MCRegisterInfo &RegInfo, const llvm::MCPhysReg PhysReg)
  45     : RegisterAliasingTracker(RegInfo) {
  46   SourceBits.set(PhysReg);
  47   FillOriginAndAliasedBits(RegInfo, SourceBits);
  48 }
  49
  50 void RegisterAliasingTracker::FillOriginAndAliasedBits(
  51     const llvm::MCRegisterInfo &RegInfo, const llvm::BitVector &SourceBits) {
  52   using RegAliasItr = llvm::MCRegAliasIterator;
  53   for (const size_t PhysReg : SourceBits.set_bits()) {
  54     for (auto Itr = RegAliasItr(PhysReg, &RegInfo, true); Itr.isValid();
  55          ++Itr) {
  56       AliasedBits.set(*Itr);
  57       Origins[*Itr] = PhysReg;
  58     }
  59   }
  60 }
  61
  62 RegisterAliasingTrackerCache::RegisterAliasingTrackerCache(
  63     const llvm::MCRegisterInfo &RegInfo, const llvm::BitVector &ReservedReg)
  64     : RegInfo(RegInfo), ReservedReg(ReservedReg),
  65       EmptyRegisters(RegInfo.getNumRegs()) {}
  66
  67 const RegisterAliasingTracker &
  68 RegisterAliasingTrackerCache::getRegister(llvm::MCPhysReg PhysReg) const {
  69   auto &Found = Registers[PhysReg];
  70   if (!Found)
  71     Found.reset(new RegisterAliasingTracker(RegInfo, PhysReg));
  72   return *Found;
  73 }
  74
  75 const RegisterAliasingTracker &
  76 RegisterAliasingTrackerCache::getRegisterClass(unsigned RegClassIndex) const {
  77   auto &Found = RegisterClasses[RegClassIndex];
  78   const auto &RegClass = RegInfo.getRegClass(RegClassIndex);
  79   if (!Found)
  80     Found.reset(new RegisterAliasingTracker(RegInfo, ReservedReg, RegClass));
  81   return *Found;
  82 }
  83
  84 } // namespace exegesis
  85 } // namespace llvm