[llvm] [mlir] [ADT] Add signed and unsigned mulh to APInt (PR #84719)
Atousa Duprat via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 1 09:00:54 PDT 2024
https://github.com/Atousa updated https://github.com/llvm/llvm-project/pull/84719
>From e9ad79cc833cf45f8ea910dbbc4de8eba43cbfab Mon Sep 17 00:00:00 2001
From: Atousa Duprat <atousa.p at gmail.com>
Date: Sun, 10 Mar 2024 21:53:04 -0700
Subject: [PATCH] [ADT] Add signed and unsigned mulh to APInt
This addresses issue #84207
---
llvm/include/llvm/ADT/APInt.h | 8 +++
.../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 17 ++----
llvm/lib/Support/APInt.cpp | 16 ++++++
llvm/unittests/ADT/APIntTest.cpp | 52 +++++++++++++++++++
llvm/unittests/Support/KnownBitsTest.cpp | 10 +---
mlir/lib/Dialect/Arith/IR/ArithOps.cpp | 8 +--
.../SPIRV/IR/SPIRVCanonicalization.cpp | 7 +--
7 files changed, 86 insertions(+), 32 deletions(-)
diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index 1abea9eb24a3c4..b9b39f3b9dfbc4 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -2216,6 +2216,14 @@ APInt avgCeilS(const APInt &C1, const APInt &C2);
/// Compute the ceil of the unsigned average of C1 and C2
APInt avgCeilU(const APInt &C1, const APInt &C2);
+/// Performs (2*N)-bit multiplication on sign-extended operands.
+/// Returns the high N bits of the multiplication result.
+APInt mulhs(const APInt &C1, const APInt &C2);
+
+/// Performs (2*N)-bit multiplication on zero-extended operands.
+/// Returns the high N bits of the multiplication result.
+APInt mulhu(const APInt &C1, const APInt &C2);
+
/// Compute GCD of two unsigned APInt values.
///
/// This function returns the greatest common divisor of the two APInt values
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index e8d1ac1d3a9167..c52864e6dcdbd2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6073,18 +6073,6 @@ static std::optional<APInt> FoldValue(unsigned Opcode, const APInt &C1,
if (!C2.getBoolValue())
break;
return C1.srem(C2);
- case ISD::MULHS: {
- unsigned FullWidth = C1.getBitWidth() * 2;
- APInt C1Ext = C1.sext(FullWidth);
- APInt C2Ext = C2.sext(FullWidth);
- return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
- }
- case ISD::MULHU: {
- unsigned FullWidth = C1.getBitWidth() * 2;
- APInt C1Ext = C1.zext(FullWidth);
- APInt C2Ext = C2.zext(FullWidth);
- return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
- }
case ISD::AVGFLOORS:
return APIntOps::avgFloorS(C1, C2);
case ISD::AVGFLOORU:
@@ -6097,10 +6085,13 @@ static std::optional<APInt> FoldValue(unsigned Opcode, const APInt &C1,
return APIntOps::abds(C1, C2);
case ISD::ABDU:
return APIntOps::abdu(C1, C2);
+ case ISD::MULHS:
+ return APIntOps::mulhs(C1, C2);
+ case ISD::MULHU:
+ return APIntOps::mulhu(C1, C2);
}
return std::nullopt;
}
-
// Handle constant folding with UNDEF.
// TODO: Handle more cases.
static std::optional<APInt> FoldValueWithUndef(unsigned Opcode, const APInt &C1,
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 7a383c3236d9b1..c20609748dc97c 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -3121,3 +3121,19 @@ APInt APIntOps::avgCeilU(const APInt &C1, const APInt &C2) {
// Return ceil((C1 + C2) / 2)
return (C1 | C2) - (C1 ^ C2).lshr(1);
}
+
+APInt APIntOps::mulhs(const APInt &C1, const APInt &C2) {
+ assert(C1.getBitWidth() == C2.getBitWidth() && "Unequal bitwidths");
+ unsigned FullWidth = C1.getBitWidth() * 2;
+ APInt C1Ext = C1.sext(FullWidth);
+ APInt C2Ext = C2.sext(FullWidth);
+ return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
+}
+
+APInt APIntOps::mulhu(const APInt &C1, const APInt &C2) {
+ assert(C1.getBitWidth() == C2.getBitWidth() && "Unequal bitwidths");
+ unsigned FullWidth = C1.getBitWidth() * 2;
+ APInt C1Ext = C1.zext(FullWidth);
+ APInt C2Ext = C2.zext(FullWidth);
+ return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
+}
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 83cbb02e0f58b3..d5ef63e38e2790 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -2841,6 +2841,58 @@ TEST(APIntTest, multiply) {
EXPECT_EQ(64U, i96.countr_zero());
}
+TEST(APIntOpsTest, Mulh) {
+
+ // Unsigned
+
+ // 32 bits
+ APInt i32a(32, 0x0001'E235);
+ APInt i32b(32, 0xF623'55AD);
+ EXPECT_EQ(0x0001'CFA1, APIntOps::mulhu(i32a, i32b));
+
+ // 64 bits
+ APInt i64a(64, 0x1234'5678'90AB'CDEF);
+ APInt i64b(64, 0xFEDC'BA09'8765'4321);
+ EXPECT_EQ(0x121F'A000'A372'3A57, APIntOps::mulhu(i64a, i64b));
+
+ // 128 bits
+ APInt i128a(128, "1234567890ABCDEF1234567890ABCDEF", 16);
+ APInt i128b(128, "FEDCBA0987654321FEDCBA0987654321", 16);
+ APInt i128Res = APIntOps::mulhu(i128a, i128b);
+ EXPECT_EQ(APInt(128, "121FA000A3723A57E68984312C3A8D7E", 16), i128Res);
+
+ // Signed
+
+ // 32 bits
+ APInt i32c(32, 0x1234'5678); // +ve
+ APInt i32d(32, 0x10AB'CDEF); // +ve
+ APInt i32e(32, 0xFEDC'BA09); // -ve
+
+ EXPECT_EQ(0x012F'7D02, APIntOps::mulhs(i32c, i32d));
+ EXPECT_EQ(0xFFEB'4988, APIntOps::mulhs(i32c, i32e));
+ EXPECT_EQ(0x0001'4B68, APIntOps::mulhs(i32e, i32e));
+
+ // 64 bits
+ APInt i64c(64, 0x1234'5678'90AB'CDEF); // +ve
+ APInt i64d(64, 0x1234'5678'90FE'DCBA); // +ve
+ APInt i64e(64, 0xFEDC'BA09'8765'4321); // -ve
+
+ EXPECT_EQ(0x014B'66DC'328E'10C1, APIntOps::mulhs(i64c, i64d));
+ EXPECT_EQ(0xFFEB'4988'12C6'6C68, APIntOps::mulhs(i64c, i64e));
+ EXPECT_EQ(0x0001'4B68'2174'FA18, APIntOps::mulhs(i64e, i64e));
+
+ // 128 bits
+ APInt i128c(128, "1234567890ABCDEF1234567890ABCDEF", 16); // +ve
+ APInt i128d(128, "1234567890FEDCBA1234567890FEDCBA", 16); // +ve
+ APInt i128e(128, "FEDCBA0987654321FEDCBA0987654321", 16); // -ve
+
+ i128Res = APIntOps::mulhs(i128c, i128d);
+ EXPECT_EQ(APInt(128, "14B66DC328E10C1FE303DF9EA0B2529", 16), i128Res);
+
+ i128Res = APIntOps::mulhs(i128c, i128e);
+ EXPECT_EQ(APInt(128, "FFEB498812C66C68D4552DB89B8EBF8F", 16), i128Res);
+}
+
TEST(APIntTest, RoundingUDiv) {
for (uint64_t Ai = 1; Ai <= 255; Ai++) {
APInt A(8, Ai);
diff --git a/llvm/unittests/Support/KnownBitsTest.cpp b/llvm/unittests/Support/KnownBitsTest.cpp
index 48de0889fdf332..027d6379af26b0 100644
--- a/llvm/unittests/Support/KnownBitsTest.cpp
+++ b/llvm/unittests/Support/KnownBitsTest.cpp
@@ -553,17 +553,11 @@ TEST(KnownBitsTest, BinaryExhaustive) {
checkCorrectnessOnlyBinary);
testBinaryOpExhaustive(
KnownBits::mulhs,
- [](const APInt &N1, const APInt &N2) {
- unsigned Bits = N1.getBitWidth();
- return (N1.sext(2 * Bits) * N2.sext(2 * Bits)).extractBits(Bits, Bits);
- },
+ [](const APInt &N1, const APInt &N2) { return APIntOps::mulhs(N1, N2); },
checkCorrectnessOnlyBinary);
testBinaryOpExhaustive(
KnownBits::mulhu,
- [](const APInt &N1, const APInt &N2) {
- unsigned Bits = N1.getBitWidth();
- return (N1.zext(2 * Bits) * N2.zext(2 * Bits)).extractBits(Bits, Bits);
- },
+ [](const APInt &N1, const APInt &N2) { return APIntOps::mulhu(N1, N2); },
checkCorrectnessOnlyBinary);
}
diff --git a/mlir/lib/Dialect/Arith/IR/ArithOps.cpp b/mlir/lib/Dialect/Arith/IR/ArithOps.cpp
index 2f32d9a26e7752..0f2811c9e30aae 100644
--- a/mlir/lib/Dialect/Arith/IR/ArithOps.cpp
+++ b/mlir/lib/Dialect/Arith/IR/ArithOps.cpp
@@ -434,9 +434,7 @@ arith::MulSIExtendedOp::fold(FoldAdaptor adaptor,
// Invoke the constant fold helper again to calculate the 'high' result.
Attribute highAttr = constFoldBinaryOp<IntegerAttr>(
adaptor.getOperands(), [](const APInt &a, const APInt &b) {
- unsigned bitWidth = a.getBitWidth();
- APInt fullProduct = a.sext(bitWidth * 2) * b.sext(bitWidth * 2);
- return fullProduct.extractBits(bitWidth, bitWidth);
+ return llvm::APIntOps::mulhs(a, b);
});
assert(highAttr && "Unexpected constant-folding failure");
@@ -491,9 +489,7 @@ arith::MulUIExtendedOp::fold(FoldAdaptor adaptor,
// Invoke the constant fold helper again to calculate the 'high' result.
Attribute highAttr = constFoldBinaryOp<IntegerAttr>(
adaptor.getOperands(), [](const APInt &a, const APInt &b) {
- unsigned bitWidth = a.getBitWidth();
- APInt fullProduct = a.zext(bitWidth * 2) * b.zext(bitWidth * 2);
- return fullProduct.extractBits(bitWidth, bitWidth);
+ return llvm::APIntOps::mulhu(a, b);
});
assert(highAttr && "Unexpected constant-folding failure");
diff --git a/mlir/lib/Dialect/SPIRV/IR/SPIRVCanonicalization.cpp b/mlir/lib/Dialect/SPIRV/IR/SPIRVCanonicalization.cpp
index 5f47cff71cba00..b1acfd1a2abedb 100644
--- a/mlir/lib/Dialect/SPIRV/IR/SPIRVCanonicalization.cpp
+++ b/mlir/lib/Dialect/SPIRV/IR/SPIRVCanonicalization.cpp
@@ -250,14 +250,11 @@ struct MulExtendedFold final : OpRewritePattern<MulOp> {
auto highBits = constFoldBinaryOp<IntegerAttr>(
{lhsAttr, rhsAttr}, [](const APInt &a, const APInt &b) {
- unsigned bitWidth = a.getBitWidth();
- APInt c;
if (IsSigned) {
- c = a.sext(bitWidth * 2) * b.sext(bitWidth * 2);
+ return llvm::APIntOps::mulhs(a, b);
} else {
- c = a.zext(bitWidth * 2) * b.zext(bitWidth * 2);
+ return llvm::APIntOps::mulhu(a, b);
}
- return c.extractBits(bitWidth, bitWidth); // Extract high result
});
if (!highBits)
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