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

   1 #include "RegisterAliasing.h"
   2
   3 #include <cassert>
   4 #include <memory>
   5
   6 #include "X86InstrInfo.h"
   7 #include "llvm/Support/TargetRegistry.h"
   8 #include "llvm/Support/TargetSelect.h"
   9 #include "gmock/gmock.h"
  10 #include "gtest/gtest.h"
  11
  12 namespace exegesis {
  13 namespace {
  14
  15 class RegisterAliasingTest : public ::testing::Test {
  16 protected:
  17   RegisterAliasingTest() {
  18     const std::string TT = "x86_64-unknown-linux";
  19     std::string error;
  20     const llvm::Target *const TheTarget =
  21         llvm::TargetRegistry::lookupTarget(TT, error);
  22     if (!TheTarget) {
  23       llvm::errs() << error << "\n";
  24       return;
  25     }
  26     MCRegInfo.reset(TheTarget->createMCRegInfo(TT));
  27   }
  28
  29   static void SetUpTestCase() {
  30     LLVMInitializeX86TargetInfo();
  31     LLVMInitializeX86Target();
  32     LLVMInitializeX86TargetMC();
  33   }
  34
  35   const llvm::MCRegisterInfo &getMCRegInfo() {
  36     assert(MCRegInfo);
  37     return *MCRegInfo;
  38   }
  39
  40 private:
  41   std::unique_ptr<const llvm::MCRegisterInfo> MCRegInfo;
  42 };
  43
  44 TEST_F(RegisterAliasingTest, TrackSimpleRegister) {
  45   const auto &RegInfo = getMCRegInfo();
  46   const RegisterAliasingTracker tracker(RegInfo, llvm::X86::EAX);
  47   std::set<llvm::MCPhysReg> ActualAliasedRegisters;
  48   for (unsigned I : tracker.aliasedBits().set_bits())
  49     ActualAliasedRegisters.insert(static_cast<llvm::MCPhysReg>(I));
  50   const std::set<llvm::MCPhysReg> ExpectedAliasedRegisters = {
  51       llvm::X86::AL,  llvm::X86::AH,  llvm::X86::AX,
  52       llvm::X86::EAX, llvm::X86::HAX, llvm::X86::RAX};
  53   ASSERT_THAT(ActualAliasedRegisters, ExpectedAliasedRegisters);
  54   for (llvm::MCPhysReg aliased : ExpectedAliasedRegisters) {
  55     ASSERT_THAT(tracker.getOrigin(aliased), llvm::X86::EAX);
  56   }
  57 }
  58
  59 TEST_F(RegisterAliasingTest, TrackRegisterClass) {
  60   // The alias bits for GR8_ABCD_LRegClassID are the union of the alias bits for
  61   // AL, BL, CL and DL.
  62   const auto &RegInfo = getMCRegInfo();
  63   const llvm::BitVector NoReservedReg(RegInfo.getNumRegs());
  64
  65   const RegisterAliasingTracker RegClassTracker(
  66       RegInfo, NoReservedReg,
  67       RegInfo.getRegClass(llvm::X86::GR8_ABCD_LRegClassID));
  68
  69   llvm::BitVector sum(RegInfo.getNumRegs());
  70   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::AL).aliasedBits();
  71   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::BL).aliasedBits();
  72   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::CL).aliasedBits();
  73   sum |= RegisterAliasingTracker(RegInfo, llvm::X86::DL).aliasedBits();
  74
  75   ASSERT_THAT(RegClassTracker.aliasedBits(), sum);
  76 }
  77
  78 TEST_F(RegisterAliasingTest, TrackRegisterClassCache) {
  79   // Fetching twice the same tracker yields the same pointers.
  80   const auto &RegInfo = getMCRegInfo();
  81   const llvm::BitVector NoReservedReg(RegInfo.getNumRegs());
  82   RegisterAliasingTrackerCache Cache(RegInfo, NoReservedReg);
  83   ASSERT_THAT(&Cache.getRegister(llvm::X86::AX),
  84               &Cache.getRegister(llvm::X86::AX));
  85
  86   ASSERT_THAT(&Cache.getRegisterClass(llvm::X86::GR8_ABCD_LRegClassID),
  87               &Cache.getRegisterClass(llvm::X86::GR8_ABCD_LRegClassID));
  88 }
  89
  90 } // namespace
  91 } // namespace exegesis