unittests/tools/llvm-exegesis/X86/RegisterAliasingTest.cpp

   1 //===-- RegisterAliasingTest.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
  10 #include "RegisterAliasing.h"
  11
  12 #include <cassert>
  13 #include <memory>
  14
  15 #include "X86InstrInfo.h"
  16 #include "llvm/Support/TargetRegistry.h"
  17 #include "llvm/Support/TargetSelect.h"
  18 #include "gmock/gmock.h"
  19 #include "gtest/gtest.h"
  20
  21 namespace llvm {
  22 namespace exegesis {
  23 namespace {
  24
  25 class RegisterAliasingTest : public ::testing::Test {
  26 protected:
  27   RegisterAliasingTest() {
  28     const std::string TT = "x86_64-unknown-linux";
  29     std::string error;
  30     const llvm::Target *const TheTarget =
  31         llvm::TargetRegistry::lookupTarget(TT, error);
  32     if (!TheTarget) {
  33       llvm::errs() << error << "\n";
  34       return;
  35     }
  36     MCRegInfo.reset(TheTarget->createMCRegInfo(TT));
  37   }
  38
  39   static void SetUpTestCase() {
  40     LLVMInitializeX86TargetInfo();
  41     LLVMInitializeX86Target();
  42     LLVMInitializeX86TargetMC();
  43   }
  44
  45   const llvm::MCRegisterInfo &getMCRegInfo() {
  46     assert(MCRegInfo);
  47     return *MCRegInfo;
  48   }
  49
  50 private:
  51   std::unique_ptr<const llvm::MCRegisterInfo> MCRegInfo;
  52 };
  53
  54 TEST_F(RegisterAliasingTest, TrackSimpleRegister) {
  55   const auto &RegInfo = getMCRegInfo();
  56   const RegisterAliasingTracker tracker(RegInfo, llvm::X86::EAX);
  57   std::set<llvm::MCPhysReg> ActualAliasedRegisters;
  58   for (unsigned I : tracker.aliasedBits().set_bits())
  59     ActualAliasedRegisters.insert(static_cast<llvm::MCPhysReg>(I));
  60   const std::set<llvm::MCPhysReg> ExpectedAliasedRegisters = {
  61       llvm::X86::AL,  llvm::X86::AH,  llvm::X86::AX,
  62       llvm::X86::EAX, llvm::X86::HAX, llvm::X86::RAX};
  63   ASSERT_THAT(ActualAliasedRegisters, ExpectedAliasedRegisters);
  64   for (llvm::MCPhysReg aliased : ExpectedAliasedRegisters) {
  65     ASSERT_THAT(tracker.getOrigin(aliased), llvm::X86::EAX);
  66   }
  67 }
  68
  69 TEST_F(RegisterAliasingTest, TrackRegisterClass) {
  70   // The alias bits for GR8_ABCD_LRegClassID are the union of the alias bits for
  71   // AL, BL, CL and DL.
  72   const auto &RegInfo = getMCRegInfo();
  73   const llvm::BitVector NoReservedReg(RegInfo.getNumRegs());
  74
  75   const RegisterAliasingTracker RegClassTracker(
  76       RegInfo, NoReservedReg,
  77       RegInfo.getRegClass(llvm::X86::GR8_ABCD_LRegClassID));
  78
  79   llvm::BitVector sum(RegInfo.getNumRegs());
  80   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::AL).aliasedBits();
  81   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::BL).aliasedBits();
  82   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::CL).aliasedBits();
  83   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::DL).aliasedBits();
  84
  85   ASSERT_THAT(RegClassTracker.aliasedBits(), sum);
  86 }
  87
  88 TEST_F(RegisterAliasingTest, TrackRegisterClassCache) {
  89   // Fetching twice the same tracker yields the same pointers.
  90   const auto &RegInfo = getMCRegInfo();
  91   const llvm::BitVector NoReservedReg(RegInfo.getNumRegs());
  92   RegisterAliasingTrackerCache Cache(RegInfo, NoReservedReg);
  93   ASSERT_THAT(&Cache.getRegister(llvm::X86::AX),
  94               &Cache.getRegister(llvm::X86::AX));
  95
  96   ASSERT_THAT(&Cache.getRegisterClass(llvm::X86::GR8_ABCD_LRegClassID),
  97               &Cache.getRegisterClass(llvm::X86::GR8_ABCD_LRegClassID));
  98 }
  99
 100 } // namespace
 101 } // namespace exegesis
 102 } // namespace llvm