KnownBitsTest.cpp

//===- KnownBitsTest.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/GISelKnownBits.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"

TEST_F(AArch64GISelMITest, TestKnownBitsCst) {
  StringRef MIRString = "  %3:_(s8) = G_CONSTANT i8 1\n"
                        "  %4:_(s8) = COPY %3\n";
  setUp(MIRString);
  if (!TM)
    return;
  unsigned CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  unsigned SrcReg = FinalCopy->getOperand(1).getReg();
  unsigned DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)1, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0xfe, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBitsCstWithClass) {
  StringRef MIRString = "  %10:gpr32 = MOVi32imm 1\n"
                        "  %4:_(s32) = COPY %10\n";
  setUp(MIRString);
  if (!TM)
    return;
  unsigned CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  unsigned SrcReg = FinalCopy->getOperand(1).getReg();
  unsigned DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  // We can't analyze %3 due to the register class constraint. We will get a
  // default-constructed KnownBits back.
  EXPECT_EQ((uint64_t)1, Res.getBitWidth());
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  // We still don't know the values due to the register class constraint but %4
  // did reveal the size of %3.
  EXPECT_EQ((uint64_t)32, Res2.getBitWidth());
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

// Check that we are able to track bits through PHIs
// and get the intersections of everything we know on each operand.
TEST_F(AArch64GISelMITest, TestKnownBitsCstPHI) {
  StringRef MIRString = "  bb.10:\n"
                        "  %10:_(s8) = G_CONSTANT i8 3\n"
                        "  %11:_(s1) = G_IMPLICIT_DEF\n"
                        "  G_BRCOND %11(s1), %bb.11\n"
                        "  G_BR %bb.12\n"
                        "\n"
                        "  bb.11:\n"
                        "  %12:_(s8) = G_CONSTANT i8 2\n"
                        "  G_BR %bb.12\n"
                        "\n"
                        "  bb.12:\n"
                        "  %13:_(s8) = PHI %10(s8), %bb.10, %12(s8), %bb.11\n"
                        "  %14:_(s8) = COPY %13\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  Register SrcReg = FinalCopy->getOperand(1).getReg();
  Register DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)2, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0xfc, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

// Check that we report we know nothing when we hit a
// non-generic register.
// Note: this could be improved though!
TEST_F(AArch64GISelMITest, TestKnownBitsCstPHIToNonGenericReg) {
  StringRef MIRString = "  bb.10:\n"
                        "  %10:gpr32 = MOVi32imm 3\n"
                        "  %11:_(s1) = G_IMPLICIT_DEF\n"
                        "  G_BRCOND %11(s1), %bb.11\n"
                        "  G_BR %bb.12\n"
                        "\n"
                        "  bb.11:\n"
                        "  %12:_(s8) = G_CONSTANT i8 2\n"
                        "  G_BR %bb.12\n"
                        "\n"
                        "  bb.12:\n"
                        "  %13:_(s8) = PHI %10, %bb.10, %12(s8), %bb.11\n"
                        "  %14:_(s8) = COPY %13\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  Register SrcReg = FinalCopy->getOperand(1).getReg();
  Register DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

// Check that we know nothing when at least one value of a PHI
// comes from something we cannot analysis.
// This test is not particularly interesting, it is just
// here to cover the code that stops the analysis of PHIs
// earlier. In that case, we would not even look at the
// second incoming value.
TEST_F(AArch64GISelMITest, TestKnownBitsUnknownPHI) {
  StringRef MIRString =
      "  bb.10:\n"
      "  %10:_(s64) = COPY %0\n"
      "  %11:_(s1) = G_IMPLICIT_DEF\n"
      "  G_BRCOND %11(s1), %bb.11\n"
      "  G_BR %bb.12\n"
      "\n"
      "  bb.11:\n"
      "  %12:_(s64) = G_CONSTANT i64 2\n"
      "  G_BR %bb.12\n"
      "\n"
      "  bb.12:\n"
      "  %13:_(s64) = PHI %10(s64), %bb.10, %12(s64), %bb.11\n"
      "  %14:_(s64) = COPY %13\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  Register SrcReg = FinalCopy->getOperand(1).getReg();
  Register DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

// Check that we manage to process PHIs that loop on themselves.
// For now, the analysis just stops and assumes it knows nothing,
// eventually we could teach it how to properly track phis that
// loop back.
TEST_F(AArch64GISelMITest, TestKnownBitsCstPHIWithLoop) {
  StringRef MIRString =
      "  bb.10:\n"
      "  %10:_(s8) = G_CONSTANT i8 3\n"
      "  %11:_(s1) = G_IMPLICIT_DEF\n"
      "  G_BRCOND %11(s1), %bb.11\n"
      "  G_BR %bb.12\n"
      "\n"
      "  bb.11:\n"
      "  %12:_(s8) = G_CONSTANT i8 2\n"
      "  G_BR %bb.12\n"
      "\n"
      "  bb.12:\n"
      "  %13:_(s8) = PHI %10(s8), %bb.10, %12(s8), %bb.11, %14(s8), %bb.12\n"
      "  %14:_(s8) = COPY %13\n"
      "  G_BR %bb.12\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  Register SrcReg = FinalCopy->getOperand(1).getReg();
  Register DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

// Check that we don't try to analysis PHIs progression.
// Setting a deep enough max depth would allow to effectively simulate
// what happens in the loop.
// Thus, with a deep enough depth, we could actually figure out
// that %14's zero known bits are actually at least what we know
// for %10, right shifted by one.
// However, this process is super expensive compile-time wise and
// we don't want to reach that conclusion while playing with max depth.
// For now, the analysis just stops and assumes it knows nothing
// on PHIs, but eventually we could teach it how to properly track
// phis that loop back without relying on the luck effect of max
// depth.
TEST_F(AArch64GISelMITest, TestKnownBitsDecreasingCstPHIWithLoop) {
  StringRef MIRString = "  bb.10:\n"
                        "  %10:_(s8) = G_CONSTANT i8 5\n"
                        "  %11:_(s8) = G_CONSTANT i8 1\n"
                        "\n"
                        "  bb.12:\n"
                        "  %13:_(s8) = PHI %10(s8), %bb.10, %14(s8), %bb.12\n"
                        "  %14:_(s8) = G_LSHR %13, %11\n"
                        "  %15:_(s8) = COPY %14\n"
                        "  G_BR %bb.12\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  Register SrcReg = FinalCopy->getOperand(1).getReg();
  Register DstReg = FinalCopy->getOperand(0).getReg();
  GISelKnownBits Info(*MF, /*MaxDepth=*/24);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  // A single iteration on the PHI (%13) gives:
  // %10 has known zero of 0xFA
  // %12 has known zero of 0x80 (we shift right by one so high bit is zero)
  // Therefore, %14's known zero are 0x80 shifted by one 0xC0.
  // If we had simulated the loop we could have more zero bits, basically
  // up to 0xFC (count leading zero of 5, + 1).
  EXPECT_EQ((uint64_t)0xC0, Res.Zero.getZExtValue());

  KnownBits Res2 = Info.getKnownBits(DstReg);
  EXPECT_EQ(Res.One.getZExtValue(), Res2.One.getZExtValue());
  EXPECT_EQ(Res.Zero.getZExtValue(), Res2.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBitsPtrToIntViceVersa) {
  StringRef MIRString = "  %3:_(s16) = G_CONSTANT i16 256\n"
                        "  %4:_(p0) = G_INTTOPTR %3\n"
                        "  %5:_(s32) = G_PTRTOINT %4\n"
                        "  %6:_(s32) = COPY %5\n";
  setUp(MIRString);
  if (!TM)
    return;
  unsigned CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  unsigned SrcReg = FinalCopy->getOperand(1).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ(256u, Res.One.getZExtValue());
  EXPECT_EQ(0xfffffeffu, Res.Zero.getZExtValue());
}
TEST_F(AArch64GISelMITest, TestKnownBitsXOR) {
  StringRef MIRString = "  %3:_(s8) = G_CONSTANT i8 4\n"
                        "  %4:_(s8) = G_CONSTANT i8 7\n"
                        "  %5:_(s8) = G_XOR %3, %4\n"
                        "  %6:_(s8) = COPY %5\n";
  setUp(MIRString);
  if (!TM)
    return;
  unsigned CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  unsigned SrcReg = FinalCopy->getOperand(1).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ(3u, Res.One.getZExtValue());
  EXPECT_EQ(252u, Res.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBits) {

  StringRef MIR = "  %3:_(s32) = G_TRUNC %0\n"
                  "  %4:_(s32) = G_TRUNC %1\n"
                  "  %5:_(s32) = G_CONSTANT i32 5\n"
                  "  %6:_(s32) = G_CONSTANT i32 24\n"
                  "  %7:_(s32) = G_CONSTANT i32 28\n"
                  "  %14:_(p0) = G_INTTOPTR %7\n"
                  "  %16:_(s32) = G_PTRTOINT %14\n"
                  "  %8:_(s32) = G_SHL %3, %5\n"
                  "  %9:_(s32) = G_SHL %4, %5\n"
                  "  %10:_(s32) = G_OR %8, %6\n"
                  "  %11:_(s32) = G_OR %9, %16\n"
                  "  %12:_(s32) = G_MUL %10, %11\n"
                  "  %13:_(s32) = COPY %12\n";
  setUp(MIR);
  if (!TM)
    return;
  unsigned CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  unsigned SrcReg = FinalCopy->getOperand(1).getReg();
  GISelKnownBits Info(*MF);
  KnownBits Known = Info.getKnownBits(SrcReg);
  EXPECT_FALSE(Known.hasConflict());
  EXPECT_EQ(0u, Known.One.getZExtValue());
  EXPECT_EQ(31u, Known.Zero.getZExtValue());
  APInt Zeroes = Info.getKnownZeroes(SrcReg);
  EXPECT_EQ(Known.Zero, Zeroes);
}

TEST_F(AArch64GISelMITest, TestSignBitIsZero) {
  setUp();
  if (!TM)
    return;

  const LLT S32 = LLT::scalar(32);
  auto SignBit = B.buildConstant(S32, 0x80000000);
  auto Zero = B.buildConstant(S32, 0);

  GISelKnownBits KnownBits(*MF);

  EXPECT_TRUE(KnownBits.signBitIsZero(Zero.getReg(0)));
  EXPECT_FALSE(KnownBits.signBitIsZero(SignBit.getReg(0)));
}

TEST_F(AArch64GISelMITest, TestNumSignBitsConstant) {
  StringRef MIRString = "  %3:_(s8) = G_CONSTANT i8 1\n"
                        "  %4:_(s8) = COPY %3\n"

                        "  %5:_(s8) = G_CONSTANT i8 -1\n"
                        "  %6:_(s8) = COPY %5\n"

                        "  %7:_(s8) = G_CONSTANT i8 127\n"
                        "  %8:_(s8) = COPY %7\n"

                        "  %9:_(s8) = G_CONSTANT i8 32\n"
                        "  %10:_(s8) = COPY %9\n"

                        "  %11:_(s8) = G_CONSTANT i8 -32\n"
                        "  %12:_(s8) = COPY %11\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyReg1 = Copies[Copies.size() - 5];
  Register CopyRegNeg1 = Copies[Copies.size() - 4];
  Register CopyReg127 = Copies[Copies.size() - 3];
  Register CopyReg32 = Copies[Copies.size() - 2];
  Register CopyRegNeg32 = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);
  EXPECT_EQ(7u, Info.computeNumSignBits(CopyReg1));
  EXPECT_EQ(8u, Info.computeNumSignBits(CopyRegNeg1));
  EXPECT_EQ(1u, Info.computeNumSignBits(CopyReg127));
  EXPECT_EQ(2u, Info.computeNumSignBits(CopyReg32));
  EXPECT_EQ(3u, Info.computeNumSignBits(CopyRegNeg32));
}

TEST_F(AArch64GISelMITest, TestNumSignBitsSext) {
  StringRef MIRString = "  %3:_(p0) = G_IMPLICIT_DEF\n"
                        "  %4:_(s8) = G_LOAD %3 :: (load 1)\n"
                        "  %5:_(s32) = G_SEXT %4\n"
                        "  %6:_(s32) = COPY %5\n"

                        "  %7:_(s8) = G_CONSTANT i8 -1\n"
                        "  %8:_(s32) = G_SEXT %7\n"
                        "  %9:_(s32) = COPY %8\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopySextLoad = Copies[Copies.size() - 2];
  Register CopySextNeg1 = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);
  EXPECT_EQ(25u, Info.computeNumSignBits(CopySextLoad));
  EXPECT_EQ(32u, Info.computeNumSignBits(CopySextNeg1));
}

TEST_F(AArch64GISelMITest, TestNumSignBitsSextInReg) {
  StringRef MIRString = R"(
   %ptr:_(p0) = G_IMPLICIT_DEF
   %load4:_(s32) = G_LOAD %ptr :: (load 4)

   %inreg7:_(s32) = G_SEXT_INREG %load4, 7
   %copy_inreg7:_(s32) = COPY %inreg7

   %inreg8:_(s32) = G_SEXT_INREG %load4, 8
   %copy_inreg8:_(s32) = COPY %inreg8

   %inreg9:_(s32) = G_SEXT_INREG %load4, 9
   %copy_inreg9:_(s32) = COPY %inreg9

   %inreg31:_(s32) = G_SEXT_INREG %load4, 31
   %copy_inreg31:_(s32) = COPY %inreg31

   %load1:_(s8) = G_LOAD %ptr :: (load 1)
   %sext_load1:_(s32) = G_SEXT %load1

   %inreg6_sext:_(s32) = G_SEXT_INREG %sext_load1, 6
   %copy_inreg6_sext:_(s32) = COPY %inreg6_sext

   %inreg7_sext:_(s32) = G_SEXT_INREG %sext_load1, 7
   %copy_inreg7_sext:_(s32) = COPY %inreg7_sext

   %inreg8_sext:_(s32) = G_SEXT_INREG %sext_load1, 8
   %copy_inreg8_sext:_(s32) = COPY %inreg8_sext

   %inreg9_sext:_(s32) = G_SEXT_INREG %sext_load1, 9
   %copy_inreg9_sext:_(s32) = COPY %inreg9_sext

   %inreg31_sext:_(s32) = G_SEXT_INREG %sext_load1, 31
   %copy_inreg31_sext:_(s32) = COPY %inreg31_sext
)";

  setUp(MIRString);
  if (!TM)
    return;

  Register CopyInReg7 = Copies[Copies.size() - 9];
  Register CopyInReg8 = Copies[Copies.size() - 8];
  Register CopyInReg9 = Copies[Copies.size() - 7];
  Register CopyInReg31 = Copies[Copies.size() - 6];

  Register CopyInReg6Sext = Copies[Copies.size() - 5];
  Register CopyInReg7Sext = Copies[Copies.size() - 4];
  Register CopyInReg8Sext = Copies[Copies.size() - 3];
  Register CopyInReg9Sext = Copies[Copies.size() - 2];
  Register CopyInReg31Sext = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);
  EXPECT_EQ(26u, Info.computeNumSignBits(CopyInReg7));
  EXPECT_EQ(25u, Info.computeNumSignBits(CopyInReg8));
  EXPECT_EQ(24u, Info.computeNumSignBits(CopyInReg9));
  EXPECT_EQ(2u, Info.computeNumSignBits(CopyInReg31));

  EXPECT_EQ(27u, Info.computeNumSignBits(CopyInReg6Sext));
  EXPECT_EQ(26u, Info.computeNumSignBits(CopyInReg7Sext));
  EXPECT_EQ(25u, Info.computeNumSignBits(CopyInReg8Sext));
  EXPECT_EQ(25u, Info.computeNumSignBits(CopyInReg9Sext));
  EXPECT_EQ(25u, Info.computeNumSignBits(CopyInReg31Sext));
}

TEST_F(AArch64GISelMITest, TestNumSignBitsTrunc) {
  StringRef MIRString = "  %3:_(p0) = G_IMPLICIT_DEF\n"
                        "  %4:_(s32) = G_LOAD %3 :: (load 4)\n"
                        "  %5:_(s8) = G_TRUNC %4\n"
                        "  %6:_(s8) = COPY %5\n"

                        "  %7:_(s32) = G_CONSTANT i32 -1\n"
                        "  %8:_(s8) = G_TRUNC %7\n"
                        "  %9:_(s8) = COPY %8\n"

                        "  %10:_(s32) = G_CONSTANT i32 7\n"
                        "  %11:_(s8) = G_TRUNC %10\n"
                        "  %12:_(s8) = COPY %11\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyTruncLoad = Copies[Copies.size() - 3];
  Register CopyTruncNeg1 = Copies[Copies.size() - 2];
  Register CopyTrunc7 = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);
  EXPECT_EQ(1u, Info.computeNumSignBits(CopyTruncLoad));
  EXPECT_EQ(8u, Info.computeNumSignBits(CopyTruncNeg1));
  EXPECT_EQ(5u, Info.computeNumSignBits(CopyTrunc7));
}

TEST_F(AMDGPUGISelMITest, TestNumSignBitsTrunc) {
  StringRef MIRString =
    "  %3:_(<4 x s32>) = G_IMPLICIT_DEF\n"
    "  %4:_(s32) = G_IMPLICIT_DEF\n"
    "  %5:_(s32) = G_AMDGPU_BUFFER_LOAD_UBYTE %3, %4, %4, %4, 0, 0, 0 :: (load 1)\n"
    "  %6:_(s32) = COPY %5\n"

    "  %7:_(s32) = G_AMDGPU_BUFFER_LOAD_SBYTE %3, %4, %4, %4, 0, 0, 0 :: (load 1)\n"
    "  %8:_(s32) = COPY %7\n"

    "  %9:_(s32) = G_AMDGPU_BUFFER_LOAD_USHORT %3, %4, %4, %4, 0, 0, 0 :: (load 2)\n"
    "  %10:_(s32) = COPY %9\n"

    "  %11:_(s32) = G_AMDGPU_BUFFER_LOAD_SSHORT %3, %4, %4, %4, 0, 0, 0 :: (load 2)\n"
    "  %12:_(s32) = COPY %11\n";

  setUp(MIRString);
  if (!TM)
    return;

  Register CopyLoadUByte = Copies[Copies.size() - 4];
  Register CopyLoadSByte = Copies[Copies.size() - 3];
  Register CopyLoadUShort = Copies[Copies.size() - 2];
  Register CopyLoadSShort = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);

  EXPECT_EQ(24u, Info.computeNumSignBits(CopyLoadUByte));
  EXPECT_EQ(25u, Info.computeNumSignBits(CopyLoadSByte));
  EXPECT_EQ(16u, Info.computeNumSignBits(CopyLoadUShort));
  EXPECT_EQ(17u, Info.computeNumSignBits(CopyLoadSShort));
}

TEST_F(AMDGPUGISelMITest, TestTargetKnownAlign) {
  StringRef MIRString =
    "  %5:_(p4) = G_INTRINSIC intrinsic(@llvm.amdgcn.dispatch.ptr)\n"
    "  %6:_(p4) = COPY %5\n"
    "  %7:_(p4) = G_INTRINSIC intrinsic(@llvm.amdgcn.queue.ptr)\n"
    "  %8:_(p4) = COPY %7\n"
    "  %9:_(p4) = G_INTRINSIC intrinsic(@llvm.amdgcn.kernarg.segment.ptr)\n"
    "  %10:_(p4) = COPY %9\n"
    "  %11:_(p4) = G_INTRINSIC intrinsic(@llvm.amdgcn.implicitarg.ptr)\n"
    "  %12:_(p4) = COPY %11\n"
    "  %13:_(p4) = G_INTRINSIC intrinsic(@llvm.amdgcn.implicit.buffer.ptr)\n"
    "  %14:_(p4) = COPY %13\n";

  setUp(MIRString);
  if (!TM)
    return;

  Register CopyDispatchPtr = Copies[Copies.size() - 5];
  Register CopyQueuePtr = Copies[Copies.size() - 4];
  Register CopyKernargSegmentPtr = Copies[Copies.size() - 3];
  Register CopyImplicitArgPtr = Copies[Copies.size() - 2];
  Register CopyImplicitBufferPtr = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);

  EXPECT_EQ(Align(4), Info.computeKnownAlignment(CopyDispatchPtr));
  EXPECT_EQ(Align(4), Info.computeKnownAlignment(CopyQueuePtr));
  EXPECT_EQ(Align(4), Info.computeKnownAlignment(CopyKernargSegmentPtr));
  EXPECT_EQ(Align(4), Info.computeKnownAlignment(CopyImplicitArgPtr));
  EXPECT_EQ(Align(4), Info.computeKnownAlignment(CopyImplicitBufferPtr));
}

TEST_F(AArch64GISelMITest, TestMetadata) {
  StringRef MIRString = "  %imp:_(p0) = G_IMPLICIT_DEF\n"
                        "  %load:_(s8) = G_LOAD %imp(p0) :: (load 1)\n"
                        "  %ext:_(s32) = G_ZEXT %load(s8)\n"
                        "  %cst:_(s32) = G_CONSTANT i32 1\n"
                        "  %and:_(s32) = G_AND %ext, %cst\n"
                        "  %copy:_(s32) = COPY %and(s32)\n";
  setUp(MIRString);
  if (!TM)
    return;

  Register CopyReg = Copies[Copies.size() - 1];
  MachineInstr *FinalCopy = MRI->getVRegDef(CopyReg);
  Register SrcReg = FinalCopy->getOperand(1).getReg();

  // We need a load with a metadata range for this to break. Fudge the load in
  // the string and replace it with something we can work with.
  MachineInstr *And = MRI->getVRegDef(SrcReg);
  MachineInstr *Ext = MRI->getVRegDef(And->getOperand(1).getReg());
  MachineInstr *Load = MRI->getVRegDef(Ext->getOperand(1).getReg());
  IntegerType *Int8Ty = Type::getInt8Ty(Context);

  // Value must be in [0, 2)
  Metadata *LowAndHigh[] = {
      ConstantAsMetadata::get(ConstantInt::get(Int8Ty, 0)),
      ConstantAsMetadata::get(ConstantInt::get(Int8Ty, 2))};
  auto NewMDNode = MDNode::get(Context, LowAndHigh);
  const MachineMemOperand *OldMMO = *Load->memoperands_begin();
  MachineMemOperand NewMMO(OldMMO->getPointerInfo(), OldMMO->getFlags(),
                           OldMMO->getSizeInBits(), OldMMO->getAlign(),
                           OldMMO->getAAInfo(), NewMDNode);
  MachineIRBuilder MIB(*Load);
  MIB.buildLoad(Load->getOperand(0), Load->getOperand(1), NewMMO);
  Load->eraseFromParent();

  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(And->getOperand(1).getReg());

  // We don't know what the result of the load is, so we don't know any ones.
  EXPECT_TRUE(Res.One.isNullValue());

  // We know that the value is in [0, 2). So, we don't know if the first bit
  // is 0 or not. However, we do know that every other bit must be 0.
  APInt Mask(Res.getBitWidth(), 1);
  Mask.flipAllBits();
  EXPECT_EQ(Mask.getZExtValue(), Res.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBitsExt) {
  StringRef MIRString = "  %c1:_(s16) = G_CONSTANT i16 1\n"
                        "  %x:_(s16) = G_IMPLICIT_DEF\n"
                        "  %y:_(s16) = G_AND %x, %c1\n"
                        "  %anyext:_(s32) = G_ANYEXT %y(s16)\n"
                        "  %r1:_(s32) = COPY %anyext\n"
                        "  %zext:_(s32) = G_ZEXT %y(s16)\n"
                        "  %r2:_(s32) = COPY %zext\n"
                        "  %sext:_(s32) = G_SEXT %y(s16)\n"
                        "  %r3:_(s32) = COPY %sext\n";
  setUp(MIRString);
  if (!TM)
    return;
  Register CopyRegAny = Copies[Copies.size() - 3];
  Register CopyRegZ = Copies[Copies.size() - 2];
  Register CopyRegS = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);
  MachineInstr *Copy;
  Register SrcReg;
  KnownBits Res;

  Copy = MRI->getVRegDef(CopyRegAny);
  SrcReg = Copy->getOperand(1).getReg();
  Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)32, Res.getBitWidth());
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0x0000fffe, Res.Zero.getZExtValue());

  Copy = MRI->getVRegDef(CopyRegZ);
  SrcReg = Copy->getOperand(1).getReg();
  Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)32, Res.getBitWidth());
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0xfffffffe, Res.Zero.getZExtValue());

  Copy = MRI->getVRegDef(CopyRegS);
  SrcReg = Copy->getOperand(1).getReg();
  Res = Info.getKnownBits(SrcReg);
  EXPECT_EQ((uint64_t)32, Res.getBitWidth());
  EXPECT_EQ((uint64_t)0, Res.One.getZExtValue());
  EXPECT_EQ((uint64_t)0xfffffffe, Res.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBitsMergeValues) {
  StringRef MIRString = R"(
   %val0:_(s16) = G_CONSTANT i16 35224
   %val1:_(s16) = G_CONSTANT i16 17494
   %val2:_(s16) = G_CONSTANT i16 4659
   %val3:_(s16) = G_CONSTANT i16 43981
   %merge:_(s64) = G_MERGE_VALUES %val0, %val1, %val2, %val3
   %mergecopy:_(s64) = COPY %merge
)";
  setUp(MIRString);
  if (!TM)
    return;

  const uint64_t TestVal = UINT64_C(0xabcd123344568998);
  Register CopyMerge = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);
  KnownBits Res = Info.getKnownBits(CopyMerge);
  EXPECT_EQ(64u, Res.getBitWidth());
  EXPECT_EQ(TestVal, Res.One.getZExtValue());
  EXPECT_EQ(~TestVal, Res.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBitsUnmergeValues) {
  StringRef MIRString = R"(
   %val:_(s64) = G_CONSTANT i64 12379570962110515608
   %val0:_(s16), %val1:_(s16), %val2:_(s16), %val3:_(s16) = G_UNMERGE_VALUES %val
   %part0:_(s16) = COPY %val0
   %part1:_(s16) = COPY %val1
   %part2:_(s16) = COPY %val2
   %part3:_(s16) = COPY %val3

)";
  setUp(MIRString);
  if (!TM)
    return;

  const uint64_t TestVal = UINT64_C(0xabcd123344568998);
  GISelKnownBits Info(*MF);

  int Offset = -4;
  for (unsigned BitOffset = 0; BitOffset != 64; BitOffset += 16, ++Offset) {
    Register Part = Copies[Copies.size() + Offset];
    KnownBits PartKnown = Info.getKnownBits(Part);
    EXPECT_EQ(16u, PartKnown.getBitWidth());

    uint16_t PartTestVal = static_cast<uint16_t>(TestVal >> BitOffset);
    EXPECT_EQ(PartTestVal, PartKnown.One.getZExtValue());
    EXPECT_EQ(static_cast<uint16_t>(~PartTestVal), PartKnown.Zero.getZExtValue());
  }
}

TEST_F(AArch64GISelMITest, TestKnownBitsBSwapBitReverse) {
  StringRef MIRString = R"(
   %const:_(s32) = G_CONSTANT i32 287454020
   %bswap:_(s32) = G_BSWAP %const
   %bitreverse:_(s32) = G_BITREVERSE %const
   %copy_bswap:_(s32) = COPY %bswap
   %copy_bitreverse:_(s32) = COPY %bitreverse
)";
  setUp(MIRString);
  if (!TM)
    return;

  const uint32_t TestVal = 0x11223344;

  Register CopyBSwap = Copies[Copies.size() - 2];
  Register CopyBitReverse = Copies[Copies.size() - 1];

  GISelKnownBits Info(*MF);

  KnownBits BSwapKnown = Info.getKnownBits(CopyBSwap);
  EXPECT_EQ(32u, BSwapKnown.getBitWidth());
  EXPECT_EQ(TestVal, BSwapKnown.One.getZExtValue());
  EXPECT_EQ(~TestVal, BSwapKnown.Zero.getZExtValue());

  KnownBits BitReverseKnown = Info.getKnownBits(CopyBitReverse);
  EXPECT_EQ(32u, BitReverseKnown.getBitWidth());
  EXPECT_EQ(TestVal, BitReverseKnown.One.getZExtValue());
  EXPECT_EQ(~TestVal, BitReverseKnown.Zero.getZExtValue());
}

TEST_F(AArch64GISelMITest, TestKnownBitsUMax) {
  StringRef MIRString = R"(
   %val:_(s32) = COPY $w0
   %zext:_(s64) = G_ZEXT %val
   %const:_(s64) = G_CONSTANT i64 -256
   %umax:_(s64) = G_UMAX %zext, %const
   %copy_umax:_(s64) = COPY %umax
)";
  setUp(MIRString);
  if (!TM)
    return;

  Register CopyUMax = Copies[Copies.size() - 1];
  GISelKnownBits Info(*MF);

  KnownBits KnownUmax = Info.getKnownBits(CopyUMax);
  EXPECT_EQ(64u, KnownUmax.getBitWidth());
  EXPECT_EQ(0u, KnownUmax.Zero.getZExtValue());
  EXPECT_EQ(0xffffffffffffff00, KnownUmax.One.getZExtValue());

  EXPECT_EQ(0u, KnownUmax.Zero.getZExtValue());
  EXPECT_EQ(0xffffffffffffff00, KnownUmax.One.getZExtValue());
}