[llvm] [Support] Add KnownBits::computeForSubBorrow (PR #67788)
Christian Kissig via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 29 06:03:50 PDT 2023
https://github.com/christiankissig updated https://github.com/llvm/llvm-project/pull/67788
>From 5d86936c3a48c613460983c980271fcab8128b75 Mon Sep 17 00:00:00 2001
From: Christian Kissig <dev at kissig.fastmail.fm>
Date: Tue, 26 Sep 2023 12:18:59 +0000
Subject: [PATCH 1/5] [Support] Add KnownBits::computeForSubBorrow
* Implements computeForSubBorrow as alias for computeforAddCarry. Borrow
is expected to be 1-bit wide.
* Adds exhaustive unit test.
---
llvm/include/llvm/Support/KnownBits.h | 4 +++
llvm/lib/Support/KnownBits.cpp | 12 +++++++++
llvm/unittests/Support/KnownBitsTest.cpp | 31 ++++++++++++++++++++++++
3 files changed, 47 insertions(+)
diff --git a/llvm/include/llvm/Support/KnownBits.h b/llvm/include/llvm/Support/KnownBits.h
index 8462aa11202d5d7..711ca8c12129a1b 100644
--- a/llvm/include/llvm/Support/KnownBits.h
+++ b/llvm/include/llvm/Support/KnownBits.h
@@ -332,6 +332,10 @@ struct KnownBits {
static KnownBits computeForAddSub(bool Add, bool NSW, const KnownBits &LHS,
KnownBits RHS);
+ /// Compute known bits results from subtracting RHS from LHS.
+ static KnownBits computeForSubBorrow(const KnownBits &LHS, KnownBits RHS,
+ const KnownBits &Borrow);
+
/// Compute knownbits resulting from llvm.sadd.sat(LHS, RHS)
static KnownBits sadd_sat(const KnownBits &LHS, const KnownBits &RHS);
diff --git a/llvm/lib/Support/KnownBits.cpp b/llvm/lib/Support/KnownBits.cpp
index 097c22d33dd12ba..99ac50a34666fce 100644
--- a/llvm/lib/Support/KnownBits.cpp
+++ b/llvm/lib/Support/KnownBits.cpp
@@ -85,6 +85,18 @@ KnownBits KnownBits::computeForAddSub(bool Add, bool NSW,
return KnownOut;
}
+KnownBits KnownBits::computeForSubBorrow(const KnownBits &LHS, KnownBits RHS,
+ const KnownBits &Borrow) {
+ assert(Borrow.getBitWidth() == 1 && "Borrow must be 1-bit");
+
+ // LHS - RHS = LHS + ~RHS + 1
+ // Carry 1 - Borrow in ::computeForAddCarry
+ std::swap(RHS.Zero, RHS.One);
+ return ::computeForAddCarry(LHS, RHS,
+ /*CarryZero*/ Borrow.One.getBoolValue(),
+ /*CarryOne*/ Borrow.Zero.getBoolValue());
+}
+
KnownBits KnownBits::sextInReg(unsigned SrcBitWidth) const {
unsigned BitWidth = getBitWidth();
assert(0 < SrcBitWidth && SrcBitWidth <= BitWidth &&
diff --git a/llvm/unittests/Support/KnownBitsTest.cpp b/llvm/unittests/Support/KnownBitsTest.cpp
index 9d184beea3ba9e9..5597d69ab248d23 100644
--- a/llvm/unittests/Support/KnownBitsTest.cpp
+++ b/llvm/unittests/Support/KnownBitsTest.cpp
@@ -213,6 +213,37 @@ TEST(KnownBitsTest, AddSubExhaustive) {
TestAddSubExhaustive(false);
}
+TEST(KnownBitsTest, SubBorrowExhaustive) {
+ unsigned Bits = 4;
+ ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
+ ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
+ ForeachKnownBits(1, [&](const KnownBits &KnownBorrow) {
+ // Explicitly compute known bits of the addition by trying all
+ // possibilities.
+ KnownBits Known(Bits);
+ Known.Zero.setAllBits();
+ Known.One.setAllBits();
+ ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
+ ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
+ ForeachNumInKnownBits(KnownBorrow, [&](const APInt &Borrow) {
+ APInt Sub = N1 - N2;
+ if (Borrow.getBoolValue())
+ --Sub;
+
+ Known.One &= Sub;
+ Known.Zero &= ~Sub;
+ });
+ });
+ });
+
+ KnownBits KnownComputed =
+ KnownBits::computeForSubBorrow(Known1, Known2, KnownBorrow);
+ EXPECT_EQ(Known, KnownComputed);
+ });
+ });
+ });
+}
+
TEST(KnownBitsTest, BinaryExhaustive) {
testBinaryOpExhaustive(
[](const KnownBits &Known1, const KnownBits &Known2) {
>From f84c882cf429df238054d88ee07e41a08ae3fd6c Mon Sep 17 00:00:00 2001
From: Christian Kissig <dev at kissig.fastmail.fm>
Date: Tue, 26 Sep 2023 18:02:49 +0000
Subject: [PATCH 2/5] [CodeGen] Implement USUBC, USUBO_CARRY, and SSUBO_CARRY
with KnownBits::computeForSubBorrow
---
.../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 12 ++++++----
.../CodeGen/AArch64SelectionDAGTest.cpp | 24 +++++++++++++++++++
2 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index cd21af770e1a4d9..ab3e9b4bdc67402 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3732,14 +3732,18 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts,
assert(Op.getResNo() == 0 &&
"We only compute knownbits for the difference here.");
- // TODO: Compute influence of the carry operand.
+ // With UADDO_CARRY and SSUBO_CARRY a borrow bit may be added in.
+ KnownBits Borrow(1);
if (Opcode == ISD::USUBO_CARRY || Opcode == ISD::SSUBO_CARRY)
- break;
+ // TODO: Compute known bits for the carry operand. Creates
+ // parity with UADDO_CARRY And SADDO_CARRY as of now.
+ Borrow.resetAll();
+ else
+ Borrow.setAllZero();
Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
Known2 = computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);
- Known = KnownBits::computeForAddSub(/* Add */ false, /* NSW */ false,
- Known, Known2);
+ Known = KnownBits::computeForSubBorrow(Known, Known2, Borrow);
break;
}
case ISD::UADDO:
diff --git a/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp b/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
index 0e1f2736907fff8..303ee50a763fba3 100644
--- a/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
+++ b/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
@@ -273,6 +273,30 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_SUB) {
EXPECT_EQ(Known.One, APInt(8, 0x1));
}
+// Piggy-backing on the AArch64 tests to verify SelectionDAG::computeKnownBits.
+TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_USUBO_CARRY) {
+ SDLoc Loc;
+ auto IntVT = EVT::getIntegerVT(Context, 8);
+ auto N0 = DAG->getConstant(0x5a, Loc, IntVT);
+ auto UnknownOp1 = DAG->getRegister(0, IntVT); // ????????
+ auto Mask1_Zero = DAG->getConstant(0x8, Loc, IntVT); // 00001000
+ auto Mask1_One = DAG->getConstant(0x20, Loc, IntVT); // 00100000
+ // N1 = (???????? & 00001000) | 00100000 = 0010?000
+ auto N1 = DAG->getNode(ISD::AND, Loc, IntVT, Mask1_Zero, UnknownOp1);
+ N1 = DAG->getNode(ISD::OR, Loc, IntVT, Mask1_One, N1);
+ auto UnknownOpC = DAG->getRegister(1, IntVT);
+ auto Op = DAG->getNode(ISD::USUBO_CARRY, Loc, IntVT, N0, N1, UnknownOpC);
+ // N0 = 01011010
+ // N1 = 0010?000
+ // C = ?
+ // =>
+ // Known.Zero = 11000100 (0xc4)
+ // Known.One = 00110000 (0x30)
+ KnownBits Known = DAG->computeKnownBits(Op);
+ EXPECT_EQ(Known.Zero, APInt(8, 0xc4));
+ EXPECT_EQ(Known.One, APInt(8, 0x30));
+}
+
TEST_F(AArch64SelectionDAGTest, isSplatValue_Fixed_BUILD_VECTOR) {
TargetLowering TL(*TM);
>From 6355b54bafcec96770624a6a5df8e0c299be8f3f Mon Sep 17 00:00:00 2001
From: Christian Kissig <dev at kissig.fastmail.fm>
Date: Wed, 27 Sep 2023 12:35:59 +0000
Subject: [PATCH 3/5] [CodeGen] Compute unknown bits for Carry/Borrow for
ADD/SUB
Computes known bits for carry/borrow for UADDO_CARRY and USUBO_CARRY
Operations. Carry/borrow are expected to be 1-bit. 0 bits are padded
with unknown.
Adds a unit test for UADDO_CARRY and USUBO_CARRY.
---
.../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 23 ++---
.../CodeGen/AArch64SelectionDAGTest.cpp | 95 +++++++++++++++++--
2 files changed, 99 insertions(+), 19 deletions(-)
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index ab3e9b4bdc67402..5c01baa9dedff4e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3734,11 +3734,11 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts,
// With UADDO_CARRY and SSUBO_CARRY a borrow bit may be added in.
KnownBits Borrow(1);
- if (Opcode == ISD::USUBO_CARRY || Opcode == ISD::SSUBO_CARRY)
- // TODO: Compute known bits for the carry operand. Creates
- // parity with UADDO_CARRY And SADDO_CARRY as of now.
- Borrow.resetAll();
- else
+ if (Opcode == ISD::USUBO_CARRY || Opcode == ISD::SSUBO_CARRY) {
+ Borrow = computeKnownBits(Op.getOperand(2), DemandedElts, Depth + 1);
+ // Borrow has bit width 1
+ Borrow = Borrow.zextOrTrunc(1);
+ } else
Borrow.setAllZero();
Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
@@ -3768,14 +3768,11 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts,
if (Opcode == ISD::ADDE)
// Can't track carry from glue, set carry to unknown.
Carry.resetAll();
- else if (Opcode == ISD::UADDO_CARRY || Opcode == ISD::SADDO_CARRY)
- // TODO: Compute known bits for the carry operand. Not sure if it is worth
- // the trouble (how often will we find a known carry bit). And I haven't
- // tested this very much yet, but something like this might work:
- // Carry = computeKnownBits(Op.getOperand(2), DemandedElts, Depth + 1);
- // Carry = Carry.zextOrTrunc(1, false);
- Carry.resetAll();
- else
+ else if (Opcode == ISD::UADDO_CARRY || Opcode == ISD::SADDO_CARRY) {
+ Carry = computeKnownBits(Op.getOperand(2), DemandedElts, Depth + 1);
+ // Carry has bit width 1
+ Carry = Carry.zextOrTrunc(1);
+ } else
Carry.setAllZero();
Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
diff --git a/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp b/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
index 303ee50a763fba3..0430c74f7d17ca8 100644
--- a/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
+++ b/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
@@ -254,6 +254,59 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_ADD) {
EXPECT_EQ(Known.One, APInt(8, 0x55));
}
+// Piggy-backing on the AArch64 tests to verify SelectionDAG::computeKnownBits.
+TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_UADDO_CARRY) {
+ SDLoc Loc;
+ auto IntVT = EVT::getIntegerVT(Context, 8);
+ auto UnknownOp = DAG->getRegister(0, IntVT);
+ auto Mask_Zero = DAG->getConstant(0x28, Loc, IntVT);
+ auto Mask_One = DAG->getConstant(0x20, Loc, IntVT);
+ auto N0 = DAG->getNode(ISD::AND, Loc, IntVT, Mask_Zero, UnknownOp);
+ N0 = DAG->getNode(ISD::OR, Loc, IntVT, Mask_One, N0);
+ auto N1 = DAG->getConstant(0x65, Loc, IntVT);
+
+ KnownBits Known;
+
+ auto UnknownBorrow = DAG->getRegister(1, IntVT);
+ auto OpUnknownBorrow = DAG->getNode(
+ ISD::UADDO_CARRY, Loc, IntVT, N0, N1, UnknownBorrow);
+ // N0 = 0010?000
+ // N1 = 01100101
+ // B = ?
+ // =>
+ // Known.Zero = 01110000 (0x70)
+ // Known.One = 10000100 (0x84)
+ Known = DAG->computeKnownBits(OpUnknownBorrow);
+ EXPECT_EQ(Known.Zero, APInt(8, 0x70));
+ EXPECT_EQ(Known.One, APInt(8, 0x84));
+
+ auto ZeroBorrow = DAG->getConstant(0x0, Loc, IntVT);
+ auto OpZeroBorrow = DAG->getNode(
+ ISD::UADDO_CARRY, Loc, IntVT, N0, N1, ZeroBorrow);
+ // N0 = 0010?000
+ // N1 = 01100101
+ // B = 0
+ // =>
+ // Known.Zero = 01110010 (0x72)
+ // Known.One = 10000101 (0x85)
+ Known = DAG->computeKnownBits(OpZeroBorrow);
+ EXPECT_EQ(Known.Zero, APInt(8, 0x72));
+ EXPECT_EQ(Known.One, APInt(8, 0x85));
+
+ auto OneBorrow = DAG->getConstant(0x1, Loc, IntVT);
+ auto OpOneBorrow = DAG->getNode(
+ ISD::UADDO_CARRY, Loc, IntVT, N0, N1, OneBorrow);
+ // N0 = 0010?000
+ // N1 = 01100101
+ // B = 1
+ // =>
+ // Known.Zero = 01110001 (0x71)
+ // Known.One = 10000110 (0x86)
+ Known = DAG->computeKnownBits(OpOneBorrow);
+ EXPECT_EQ(Known.Zero, APInt(8, 0x71));
+ EXPECT_EQ(Known.One, APInt(8, 0x86));
+}
+
// Piggy-backing on the AArch64 tests to verify SelectionDAG::computeKnownBits.
TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_SUB) {
SDLoc Loc;
@@ -278,23 +331,53 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_USUBO_CARRY) {
SDLoc Loc;
auto IntVT = EVT::getIntegerVT(Context, 8);
auto N0 = DAG->getConstant(0x5a, Loc, IntVT);
- auto UnknownOp1 = DAG->getRegister(0, IntVT); // ????????
+ auto UnknownOp = DAG->getRegister(0, IntVT); // ????????
auto Mask1_Zero = DAG->getConstant(0x8, Loc, IntVT); // 00001000
auto Mask1_One = DAG->getConstant(0x20, Loc, IntVT); // 00100000
// N1 = (???????? & 00001000) | 00100000 = 0010?000
- auto N1 = DAG->getNode(ISD::AND, Loc, IntVT, Mask1_Zero, UnknownOp1);
+ auto N1 = DAG->getNode(ISD::AND, Loc, IntVT, Mask1_Zero, UnknownOp);
N1 = DAG->getNode(ISD::OR, Loc, IntVT, Mask1_One, N1);
- auto UnknownOpC = DAG->getRegister(1, IntVT);
- auto Op = DAG->getNode(ISD::USUBO_CARRY, Loc, IntVT, N0, N1, UnknownOpC);
+
+ KnownBits Known;
+
+ auto UnknownBorrow = DAG->getRegister(1, IntVT);
+ auto OpUnknownBorrow = DAG->getNode(
+ ISD::USUBO_CARRY, Loc, IntVT, N0, N1, UnknownBorrow);
// N0 = 01011010
// N1 = 0010?000
- // C = ?
+ // B = ?
// =>
// Known.Zero = 11000100 (0xc4)
// Known.One = 00110000 (0x30)
- KnownBits Known = DAG->computeKnownBits(Op);
+ Known = DAG->computeKnownBits(OpUnknownBorrow);
EXPECT_EQ(Known.Zero, APInt(8, 0xc4));
EXPECT_EQ(Known.One, APInt(8, 0x30));
+
+ auto ZeroBorrow = DAG->getConstant(0x0, Loc, IntVT);
+ auto OpZeroBorrow = DAG->getNode(
+ ISD::USUBO_CARRY, Loc, IntVT, N0, N1, ZeroBorrow);
+ // N0 = 01011010
+ // N1 = 0010?000
+ // B = 0
+ // =>
+ // Known.Zero = 11000101 (0xc5)
+ // Known.One = 00110010 (0x32)
+ Known = DAG->computeKnownBits(OpZeroBorrow);
+ EXPECT_EQ(Known.Zero, APInt(8, 0xc5));
+ EXPECT_EQ(Known.One, APInt(8, 0x32));
+
+ auto OneBorrow = DAG->getConstant(0x1, Loc, IntVT);
+ auto OpOneBorrow = DAG->getNode(
+ ISD::USUBO_CARRY, Loc, IntVT, N0, N1, OneBorrow);
+ // N0 = 01011010
+ // N1 = 0010?000
+ // B = 1
+ // =>
+ // Known.Zero = 11000110 (0xc6)
+ // Known.One = 00110001 (0x31)
+ Known = DAG->computeKnownBits(OpOneBorrow);
+ EXPECT_EQ(Known.Zero, APInt(8, 0xc6));
+ EXPECT_EQ(Known.One, APInt(8, 0x31));
}
TEST_F(AArch64SelectionDAGTest, isSplatValue_Fixed_BUILD_VECTOR) {
>From 108d899c04aa80e2d65fc34b49e40ae82594cf10 Mon Sep 17 00:00:00 2001
From: Christian Kissig <dev at kissig.fastmail.fm>
Date: Thu, 28 Sep 2023 11:50:25 +0000
Subject: [PATCH 4/5] [CodeGen] Compute known bits of Carry/Borrow for UADDO,
SADDO, USUBO, and SSUBO
Adds computeKnownBits for Carry/Borrow for UADDO, SADDO, USUBO, and SSUBO.
Carry over is expected to be of bit width 1. Adds unit tests for UADDO_CARRY
and USUBO_CARRY.
---
.../CodeGen/AArch64SelectionDAGTest.cpp | 28 +++++++++----------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp b/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
index 0430c74f7d17ca8..bb8e76a2eeb8beb 100644
--- a/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
+++ b/llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
@@ -268,8 +268,8 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_UADDO_CARRY) {
KnownBits Known;
auto UnknownBorrow = DAG->getRegister(1, IntVT);
- auto OpUnknownBorrow = DAG->getNode(
- ISD::UADDO_CARRY, Loc, IntVT, N0, N1, UnknownBorrow);
+ auto OpUnknownBorrow =
+ DAG->getNode(ISD::UADDO_CARRY, Loc, IntVT, N0, N1, UnknownBorrow);
// N0 = 0010?000
// N1 = 01100101
// B = ?
@@ -281,8 +281,8 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_UADDO_CARRY) {
EXPECT_EQ(Known.One, APInt(8, 0x84));
auto ZeroBorrow = DAG->getConstant(0x0, Loc, IntVT);
- auto OpZeroBorrow = DAG->getNode(
- ISD::UADDO_CARRY, Loc, IntVT, N0, N1, ZeroBorrow);
+ auto OpZeroBorrow =
+ DAG->getNode(ISD::UADDO_CARRY, Loc, IntVT, N0, N1, ZeroBorrow);
// N0 = 0010?000
// N1 = 01100101
// B = 0
@@ -294,8 +294,8 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_UADDO_CARRY) {
EXPECT_EQ(Known.One, APInt(8, 0x85));
auto OneBorrow = DAG->getConstant(0x1, Loc, IntVT);
- auto OpOneBorrow = DAG->getNode(
- ISD::UADDO_CARRY, Loc, IntVT, N0, N1, OneBorrow);
+ auto OpOneBorrow =
+ DAG->getNode(ISD::UADDO_CARRY, Loc, IntVT, N0, N1, OneBorrow);
// N0 = 0010?000
// N1 = 01100101
// B = 1
@@ -304,7 +304,7 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_UADDO_CARRY) {
// Known.One = 10000110 (0x86)
Known = DAG->computeKnownBits(OpOneBorrow);
EXPECT_EQ(Known.Zero, APInt(8, 0x71));
- EXPECT_EQ(Known.One, APInt(8, 0x86));
+ EXPECT_EQ(Known.One, APInt(8, 0x86));
}
// Piggy-backing on the AArch64 tests to verify SelectionDAG::computeKnownBits.
@@ -331,7 +331,7 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_USUBO_CARRY) {
SDLoc Loc;
auto IntVT = EVT::getIntegerVT(Context, 8);
auto N0 = DAG->getConstant(0x5a, Loc, IntVT);
- auto UnknownOp = DAG->getRegister(0, IntVT); // ????????
+ auto UnknownOp = DAG->getRegister(0, IntVT); // ????????
auto Mask1_Zero = DAG->getConstant(0x8, Loc, IntVT); // 00001000
auto Mask1_One = DAG->getConstant(0x20, Loc, IntVT); // 00100000
// N1 = (???????? & 00001000) | 00100000 = 0010?000
@@ -341,8 +341,8 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_USUBO_CARRY) {
KnownBits Known;
auto UnknownBorrow = DAG->getRegister(1, IntVT);
- auto OpUnknownBorrow = DAG->getNode(
- ISD::USUBO_CARRY, Loc, IntVT, N0, N1, UnknownBorrow);
+ auto OpUnknownBorrow =
+ DAG->getNode(ISD::USUBO_CARRY, Loc, IntVT, N0, N1, UnknownBorrow);
// N0 = 01011010
// N1 = 0010?000
// B = ?
@@ -354,8 +354,8 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_USUBO_CARRY) {
EXPECT_EQ(Known.One, APInt(8, 0x30));
auto ZeroBorrow = DAG->getConstant(0x0, Loc, IntVT);
- auto OpZeroBorrow = DAG->getNode(
- ISD::USUBO_CARRY, Loc, IntVT, N0, N1, ZeroBorrow);
+ auto OpZeroBorrow =
+ DAG->getNode(ISD::USUBO_CARRY, Loc, IntVT, N0, N1, ZeroBorrow);
// N0 = 01011010
// N1 = 0010?000
// B = 0
@@ -367,8 +367,8 @@ TEST_F(AArch64SelectionDAGTest, ComputeKnownBits_USUBO_CARRY) {
EXPECT_EQ(Known.One, APInt(8, 0x32));
auto OneBorrow = DAG->getConstant(0x1, Loc, IntVT);
- auto OpOneBorrow = DAG->getNode(
- ISD::USUBO_CARRY, Loc, IntVT, N0, N1, OneBorrow);
+ auto OpOneBorrow =
+ DAG->getNode(ISD::USUBO_CARRY, Loc, IntVT, N0, N1, OneBorrow);
// N0 = 01011010
// N1 = 0010?000
// B = 1
>From 3e91c2b0798659e48643fe3806200fb18afc812a Mon Sep 17 00:00:00 2001
From: Christian Kissig <dev at kissig.fastmail.fm>
Date: Fri, 29 Sep 2023 13:01:14 +0000
Subject: [PATCH 5/5] [CodeGen] Fix typo
---
llvm/unittests/Support/KnownBitsTest.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/unittests/Support/KnownBitsTest.cpp b/llvm/unittests/Support/KnownBitsTest.cpp
index 5597d69ab248d23..c0377d45c303a11 100644
--- a/llvm/unittests/Support/KnownBitsTest.cpp
+++ b/llvm/unittests/Support/KnownBitsTest.cpp
@@ -218,7 +218,7 @@ TEST(KnownBitsTest, SubBorrowExhaustive) {
ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
ForeachKnownBits(1, [&](const KnownBits &KnownBorrow) {
- // Explicitly compute known bits of the addition by trying all
+ // Explicitly compute known bits of the subtraction by trying all
// possibilities.
KnownBits Known(Bits);
Known.Zero.setAllBits();
More information about the llvm-commits
mailing list