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AtousaAtousa
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[ADT] Add signed and unsigned mulh to APInt
This addresses issue #84207
1 parent 362caa1 commit cf7985f

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7 files changed

+86
-36
lines changed

7 files changed

+86
-36
lines changed

‎llvm/include/llvm/ADT/APInt.h

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2205,6 +2205,14 @@ APInt avgCeilS(const APInt &C1, const APInt &C2);
22052205
/// Compute the ceil of the unsigned average of C1 and C2
22062206
APInt avgCeilU(const APInt &C1, const APInt &C2);
22072207

2208+
/// Performs (2*N)-bit multiplication on sign-extended operands.
2209+
/// Returns the high N bits of the multiplication result.
2210+
APInt mulhs(const APInt &C1, const APInt &C2);
2211+
2212+
/// Performs (2*N)-bit multiplication on zero-extended operands.
2213+
/// Returns the high N bits of the multiplication result.
2214+
APInt mulhu(const APInt &C1, const APInt &C2);
2215+
22082216
/// Compute GCD of two unsigned APInt values.
22092217
///
22102218
/// This function returns the greatest common divisor of the two APInt values

‎llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

Lines changed: 4 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -6009,18 +6009,6 @@ static std::optional<APInt> FoldValue(unsigned Opcode, const APInt &C1,
60096009
if (!C2.getBoolValue())
60106010
break;
60116011
return C1.srem(C2);
6012-
case ISD::MULHS: {
6013-
unsigned FullWidth = C1.getBitWidth() * 2;
6014-
APInt C1Ext = C1.sext(FullWidth);
6015-
APInt C2Ext = C2.sext(FullWidth);
6016-
return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
6017-
}
6018-
case ISD::MULHU: {
6019-
unsigned FullWidth = C1.getBitWidth() * 2;
6020-
APInt C1Ext = C1.zext(FullWidth);
6021-
APInt C2Ext = C2.zext(FullWidth);
6022-
return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
6023-
}
60246012
case ISD::AVGFLOORS:
60256013
return APIntOps::avgFloorS(C1, C2);
60266014
case ISD::AVGFLOORU:
@@ -6029,14 +6017,13 @@ static std::optional<APInt> FoldValue(unsigned Opcode, const APInt &C1,
60296017
return APIntOps::avgCeilS(C1, C2);
60306018
case ISD::AVGCEILU:
60316019
return APIntOps::avgCeilU(C1, C2);
6032-
case ISD::ABDS:
6033-
return APIntOps::smax(C1, C2) - APIntOps::smin(C1, C2);
6034-
case ISD::ABDU:
6035-
return APIntOps::umax(C1, C2) - APIntOps::umin(C1, C2);
6020+
case ISD::MULHS:
6021+
return APIntOps::mulhs(C1, C2);
6022+
case ISD::MULHU:
6023+
return APIntOps::mulhu(C1, C2);
60366024
}
60376025
return std::nullopt;
60386026
}
6039-
60406027
// Handle constant folding with UNDEF.
60416028
// TODO: Handle more cases.
60426029
static std::optional<APInt> FoldValueWithUndef(unsigned Opcode, const APInt &C1,

‎llvm/lib/Support/APInt.cpp

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -3130,3 +3130,19 @@ APInt APIntOps::avgCeilU(const APInt &C1, const APInt &C2) {
31303130
APInt C2Ext = C2.zext(FullWidth);
31313131
return (C1Ext + C2Ext + 1).extractBits(C1.getBitWidth(), 1);
31323132
}
3133+
3134+
APInt APIntOps::mulhs(const APInt &C1, const APInt &C2) {
3135+
assert(C1.getBitWidth() == C2.getBitWidth() && "Unequal bitwidths");
3136+
unsigned FullWidth = C1.getBitWidth() * 2;
3137+
APInt C1Ext = C1.sext(FullWidth);
3138+
APInt C2Ext = C2.sext(FullWidth);
3139+
return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
3140+
}
3141+
3142+
APInt APIntOps::mulhu(const APInt &C1, const APInt &C2) {
3143+
assert(C1.getBitWidth() == C2.getBitWidth() && "Unequal bitwidths");
3144+
unsigned FullWidth = C1.getBitWidth() * 2;
3145+
APInt C1Ext = C1.zext(FullWidth);
3146+
APInt C2Ext = C2.zext(FullWidth);
3147+
return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
3148+
}

‎llvm/unittests/ADT/APIntTest.cpp

Lines changed: 52 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2806,6 +2806,58 @@ TEST(APIntTest, multiply) {
28062806
EXPECT_EQ(64U, i96.countr_zero());
28072807
}
28082808

2809+
TEST(APIntOpsTest, Mulh) {
2810+
2811+
// Unsigned
2812+
2813+
// 32 bits
2814+
APInt i32a(32, 0x0001'E235);
2815+
APInt i32b(32, 0xF623'55AD);
2816+
EXPECT_EQ(0x0001'CFA1, APIntOps::mulhu(i32a, i32b));
2817+
2818+
// 64 bits
2819+
APInt i64a(64, 0x1234'5678'90AB'CDEF);
2820+
APInt i64b(64, 0xFEDC'BA09'8765'4321);
2821+
EXPECT_EQ(0x121F'A000'A372'3A57, APIntOps::mulhu(i64a, i64b));
2822+
2823+
// 128 bits
2824+
APInt i128a(128, "1234567890ABCDEF1234567890ABCDEF", 16);
2825+
APInt i128b(128, "FEDCBA0987654321FEDCBA0987654321", 16);
2826+
APInt i128Res = APIntOps::mulhu(i128a, i128b);
2827+
EXPECT_EQ(APInt(128, "121FA000A3723A57E68984312C3A8D7E", 16), i128Res);
2828+
2829+
// Signed
2830+
2831+
// 32 bits
2832+
APInt i32c(32, 0x1234'5678); // +ve
2833+
APInt i32d(32, 0x10AB'CDEF); // +ve
2834+
APInt i32e(32, 0xFEDC'BA09); // -ve
2835+
2836+
EXPECT_EQ(0x012F'7D02, APIntOps::mulhs(i32c, i32d));
2837+
EXPECT_EQ(0xFFEB'4988, APIntOps::mulhs(i32c, i32e));
2838+
EXPECT_EQ(0x0001'4B68, APIntOps::mulhs(i32e, i32e));
2839+
2840+
// 64 bits
2841+
APInt i64c(64, 0x1234'5678'90AB'CDEF); // +ve
2842+
APInt i64d(64, 0x1234'5678'90FE'DCBA); // +ve
2843+
APInt i64e(64, 0xFEDC'BA09'8765'4321); // -ve
2844+
2845+
EXPECT_EQ(0x014B'66DC'328E'10C1, APIntOps::mulhs(i64c, i64d));
2846+
EXPECT_EQ(0xFFEB'4988'12C6'6C68, APIntOps::mulhs(i64c, i64e));
2847+
EXPECT_EQ(0x0001'4B68'2174'FA18, APIntOps::mulhs(i64e, i64e));
2848+
2849+
// 128 bits
2850+
APInt i128c(128, "1234567890ABCDEF1234567890ABCDEF", 16); // +ve
2851+
APInt i128d(128, "1234567890FEDCBA1234567890FEDCBA", 16); // +ve
2852+
APInt i128e(128, "FEDCBA0987654321FEDCBA0987654321", 16); // -ve
2853+
2854+
i128Res = APIntOps::mulhs(i128c, i128d);
2855+
EXPECT_EQ(APInt(128, "14B66DC328E10C1FE303DF9EA0B2529", 16), i128Res);
2856+
2857+
i128Res = APIntOps::mulhs(i128c, i128e);
2858+
EXPECT_EQ(APInt(128, "FFEB498812C66C68D4552DB89B8EBF8F", 16), i128Res);
2859+
}
2860+
28092861
TEST(APIntTest, RoundingUDiv) {
28102862
for (uint64_t Ai = 1; Ai <= 255; Ai++) {
28112863
APInt A(8, Ai);

‎llvm/unittests/Support/KnownBitsTest.cpp

Lines changed: 2 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -537,19 +537,13 @@ TEST(KnownBitsTest, BinaryExhaustive) {
537537
[](const KnownBits &Known1, const KnownBits &Known2) {
538538
return KnownBits::mulhs(Known1, Known2);
539539
},
540-
[](const APInt &N1, const APInt &N2) {
541-
unsigned Bits = N1.getBitWidth();
542-
return (N1.sext(2 * Bits) * N2.sext(2 * Bits)).extractBits(Bits, Bits);
543-
},
540+
[](const APInt &N1, const APInt &N2) { return APIntOps::mulhs(N1, N2); },
544541
checkCorrectnessOnlyBinary);
545542
testBinaryOpExhaustive(
546543
[](const KnownBits &Known1, const KnownBits &Known2) {
547544
return KnownBits::mulhu(Known1, Known2);
548545
},
549-
[](const APInt &N1, const APInt &N2) {
550-
unsigned Bits = N1.getBitWidth();
551-
return (N1.zext(2 * Bits) * N2.zext(2 * Bits)).extractBits(Bits, Bits);
552-
},
546+
[](const APInt &N1, const APInt &N2) { return APIntOps::mulhu(N1, N2); },
553547
checkCorrectnessOnlyBinary);
554548
}
555549

‎mlir/lib/Dialect/Arith/IR/ArithOps.cpp

Lines changed: 2 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -434,9 +434,7 @@ arith::MulSIExtendedOp::fold(FoldAdaptor adaptor,
434434
// Invoke the constant fold helper again to calculate the 'high' result.
435435
Attribute highAttr = constFoldBinaryOp<IntegerAttr>(
436436
adaptor.getOperands(), [](const APInt &a, const APInt &b) {
437-
unsigned bitWidth = a.getBitWidth();
438-
APInt fullProduct = a.sext(bitWidth * 2) * b.sext(bitWidth * 2);
439-
return fullProduct.extractBits(bitWidth, bitWidth);
437+
return llvm::APIntOps::mulhs(a, b);
440438
});
441439
assert(highAttr && "Unexpected constant-folding failure");
442440

@@ -491,9 +489,7 @@ arith::MulUIExtendedOp::fold(FoldAdaptor adaptor,
491489
// Invoke the constant fold helper again to calculate the 'high' result.
492490
Attribute highAttr = constFoldBinaryOp<IntegerAttr>(
493491
adaptor.getOperands(), [](const APInt &a, const APInt &b) {
494-
unsigned bitWidth = a.getBitWidth();
495-
APInt fullProduct = a.zext(bitWidth * 2) * b.zext(bitWidth * 2);
496-
return fullProduct.extractBits(bitWidth, bitWidth);
492+
return llvm::APIntOps::mulhu(a, b);
497493
});
498494
assert(highAttr && "Unexpected constant-folding failure");
499495

‎mlir/lib/Dialect/SPIRV/IR/SPIRVCanonicalization.cpp

Lines changed: 2 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -250,14 +250,11 @@ struct MulExtendedFold final : OpRewritePattern<MulOp> {
250250

251251
auto highBits = constFoldBinaryOp<IntegerAttr>(
252252
{lhsAttr, rhsAttr}, [](const APInt &a, const APInt &b) {
253-
unsigned bitWidth = a.getBitWidth();
254-
APInt c;
255253
if (IsSigned) {
256-
c = a.sext(bitWidth * 2) * b.sext(bitWidth * 2);
254+
return llvm::APIntOps::mulhs(a, b);
257255
} else {
258-
c = a.zext(bitWidth * 2) * b.zext(bitWidth * 2);
256+
return llvm::APIntOps::mulhu(a, b);
259257
}
260-
return c.extractBits(bitWidth, bitWidth); // Extract high result
261258
});
262259

263260
if (!highBits)

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