src/llvm-project/llvm/unittests/CodeGen/GlobalISel/ConstantFoldingTest.cpp

//===- ConstantFoldingTest.cpp -------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "GISelMITest.h"
#include "llvm/CodeGen/GlobalISel/CSEMIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "gtest/gtest.h"

using namespace llvm;

namespace {

TEST_F(AArch64GISelMITest, FoldWithBuilder) {
  setUp();
  if (!TM)
    GTEST_SKIP();
  // Try to use the FoldableInstructionsBuilder to build binary ops.
  CSEMIRBuilder CFB(B.getState());
  LLT s32 = LLT::scalar(32);
  int64_t Cst;
  auto MIBCAdd =
      CFB.buildAdd(s32, CFB.buildConstant(s32, 0), CFB.buildConstant(s32, 1));
  // This should be a constant now.
  bool match = mi_match(MIBCAdd.getReg(0), *MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 1);
  auto MIBCAdd1 =
      CFB.buildInstr(TargetOpcode::G_ADD, {s32},
                     {CFB.buildConstant(s32, 0), CFB.buildConstant(s32, 1)});
  // This should be a constant now.
  match = mi_match(MIBCAdd1.getReg(0), *MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 1);

  // Try one of the other constructors of MachineIRBuilder to make sure it's
  // compatible.
  CSEMIRBuilder CFB1(*MF);
  CFB1.setInsertPt(*EntryMBB, EntryMBB->end());
  auto MIBCSub =
      CFB1.buildInstr(TargetOpcode::G_SUB, {s32},
                      {CFB1.buildConstant(s32, 1), CFB1.buildConstant(s32, 1)});
  // This should be a constant now.
  match = mi_match(MIBCSub.getReg(0), *MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(Cst, 0);

  auto MIBCSext1 =
      CFB1.buildInstr(TargetOpcode::G_SEXT_INREG, {s32},
                      {CFB1.buildConstant(s32, 0x01), uint64_t(8)});
  // This should be a constant now.
  match = mi_match(MIBCSext1.getReg(0), *MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(1, Cst);

  auto MIBCSext2 =
      CFB1.buildInstr(TargetOpcode::G_SEXT_INREG, {s32},
                      {CFB1.buildConstant(s32, 0x80), uint64_t(8)});
  // This should be a constant now.
  match = mi_match(MIBCSext2.getReg(0), *MRI, m_ICst(Cst));
  EXPECT_TRUE(match);
  EXPECT_EQ(-0x80, Cst);
}

TEST_F(AArch64GISelMITest, FoldBinOp) {
  setUp();
  if (!TM)
    GTEST_SKIP();

  LLT s32{LLT::scalar(32)};
  auto MIBCst1 = B.buildConstant(s32, 16);
  auto MIBCst2 = B.buildConstant(s32, 9);
  auto MIBFCst1 = B.buildFConstant(s32, 1.0000001);
  auto MIBFCst2 = B.buildFConstant(s32, 2.0);

  // Test G_ADD folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGAddInt = ConstantFoldBinOp(
      TargetOpcode::G_ADD, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGAddInt.has_value());
  EXPECT_EQ(25ULL, FoldGAddInt->getLimitedValue());
  std::optional<APInt> FoldGAddMix = ConstantFoldBinOp(
      TargetOpcode::G_ADD, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGAddMix.has_value());
  EXPECT_EQ(1073741840ULL, FoldGAddMix->getLimitedValue());

  // Test G_AND folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGAndInt = ConstantFoldBinOp(
      TargetOpcode::G_AND, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGAndInt.has_value());
  EXPECT_EQ(0ULL, FoldGAndInt->getLimitedValue());
  std::optional<APInt> FoldGAndMix = ConstantFoldBinOp(
      TargetOpcode::G_AND, MIBCst2.getReg(0), MIBFCst1.getReg(0), *MRI);
  EXPECT_TRUE(FoldGAndMix.has_value());
  EXPECT_EQ(1ULL, FoldGAndMix->getLimitedValue());

  // Test G_ASHR folding Integer + Mixed cases
  std::optional<APInt> FoldGAShrInt = ConstantFoldBinOp(
      TargetOpcode::G_ASHR, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGAShrInt.has_value());
  EXPECT_EQ(0ULL, FoldGAShrInt->getLimitedValue());
  std::optional<APInt> FoldGAShrMix = ConstantFoldBinOp(
      TargetOpcode::G_ASHR, MIBFCst2.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGAShrMix.has_value());
  EXPECT_EQ(2097152ULL, FoldGAShrMix->getLimitedValue());

  // Test G_LSHR folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGLShrInt = ConstantFoldBinOp(
      TargetOpcode::G_LSHR, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGLShrInt.has_value());
  EXPECT_EQ(0ULL, FoldGLShrInt->getLimitedValue());
  std::optional<APInt> FoldGLShrMix = ConstantFoldBinOp(
      TargetOpcode::G_LSHR, MIBFCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGLShrMix.has_value());
  EXPECT_EQ(2080768ULL, FoldGLShrMix->getLimitedValue());

  // Test G_MUL folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGMulInt = ConstantFoldBinOp(
      TargetOpcode::G_MUL, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGMulInt.has_value());
  EXPECT_EQ(144ULL, FoldGMulInt->getLimitedValue());
  std::optional<APInt> FoldGMulMix = ConstantFoldBinOp(
      TargetOpcode::G_MUL, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGMulMix.has_value());
  EXPECT_EQ(0ULL, FoldGMulMix->getLimitedValue());

  // Test G_OR folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGOrInt = ConstantFoldBinOp(
      TargetOpcode::G_OR, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGOrInt.has_value());
  EXPECT_EQ(25ULL, FoldGOrInt->getLimitedValue());
  std::optional<APInt> FoldGOrMix = ConstantFoldBinOp(
      TargetOpcode::G_OR, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGOrMix.has_value());
  EXPECT_EQ(1073741840ULL, FoldGOrMix->getLimitedValue());

  // Test G_SHL folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGShlInt = ConstantFoldBinOp(
      TargetOpcode::G_SHL, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGShlInt.has_value());
  EXPECT_EQ(8192ULL, FoldGShlInt->getLimitedValue());
  std::optional<APInt> FoldGShlMix = ConstantFoldBinOp(
      TargetOpcode::G_SHL, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGShlMix.has_value());
  EXPECT_EQ(0ULL, FoldGShlMix->getLimitedValue());

  // Test G_SUB folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGSubInt = ConstantFoldBinOp(
      TargetOpcode::G_SUB, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGSubInt.has_value());
  EXPECT_EQ(7ULL, FoldGSubInt->getLimitedValue());
  std::optional<APInt> FoldGSubMix = ConstantFoldBinOp(
      TargetOpcode::G_SUB, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGSubMix.has_value());
  EXPECT_EQ(3221225488ULL, FoldGSubMix->getLimitedValue());

  // Test G_XOR folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGXorInt = ConstantFoldBinOp(
      TargetOpcode::G_XOR, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGXorInt.has_value());
  EXPECT_EQ(25ULL, FoldGXorInt->getLimitedValue());
  std::optional<APInt> FoldGXorMix = ConstantFoldBinOp(
      TargetOpcode::G_XOR, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGXorMix.has_value());
  EXPECT_EQ(1073741840ULL, FoldGXorMix->getLimitedValue());

  // Test G_UDIV folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGUdivInt = ConstantFoldBinOp(
      TargetOpcode::G_UDIV, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGUdivInt.has_value());
  EXPECT_EQ(1ULL, FoldGUdivInt->getLimitedValue());
  std::optional<APInt> FoldGUdivMix = ConstantFoldBinOp(
      TargetOpcode::G_UDIV, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGUdivMix.has_value());
  EXPECT_EQ(0ULL, FoldGUdivMix->getLimitedValue());

  // Test G_SDIV folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGSdivInt = ConstantFoldBinOp(
      TargetOpcode::G_SDIV, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGSdivInt.has_value());
  EXPECT_EQ(1ULL, FoldGSdivInt->getLimitedValue());
  std::optional<APInt> FoldGSdivMix = ConstantFoldBinOp(
      TargetOpcode::G_SDIV, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGSdivMix.has_value());
  EXPECT_EQ(0ULL, FoldGSdivMix->getLimitedValue());

  // Test G_UREM folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGUremInt = ConstantFoldBinOp(
      TargetOpcode::G_UDIV, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGUremInt.has_value());
  EXPECT_EQ(1ULL, FoldGUremInt->getLimitedValue());
  std::optional<APInt> FoldGUremMix = ConstantFoldBinOp(
      TargetOpcode::G_UDIV, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGUremMix.has_value());
  EXPECT_EQ(0ULL, FoldGUremMix->getLimitedValue());

  // Test G_SREM folding Integer + Mixed Int-Float cases
  std::optional<APInt> FoldGSremInt = ConstantFoldBinOp(
      TargetOpcode::G_SREM, MIBCst1.getReg(0), MIBCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGSremInt.has_value());
  EXPECT_EQ(7ULL, FoldGSremInt->getLimitedValue());
  std::optional<APInt> FoldGSremMix = ConstantFoldBinOp(
      TargetOpcode::G_SREM, MIBCst1.getReg(0), MIBFCst2.getReg(0), *MRI);
  EXPECT_TRUE(FoldGSremMix.has_value());
  EXPECT_EQ(16ULL, FoldGSremMix->getLimitedValue());
}

} // namespace