/// Compute known bits resulting from multiplying LHS and RHS.
static KnownBits computeForMul(const KnownBits &LHS, const KnownBits &RHS);
+ /// Compute known bits from sign-extended multiply-hi.
+ static KnownBits mulhs(const KnownBits &LHS, const KnownBits &RHS);
+
+ /// Compute known bits from zero-extended multiply-hi.
+ static KnownBits mulhu(const KnownBits &LHS, const KnownBits &RHS);
+
/// Compute known bits for udiv(LHS, RHS).
static KnownBits udiv(const KnownBits &LHS, const KnownBits &RHS);
return Res;
}
+KnownBits KnownBits::mulhs(const KnownBits &LHS, const KnownBits &RHS) {
+ unsigned BitWidth = LHS.getBitWidth();
+ assert(BitWidth == RHS.getBitWidth() && !LHS.hasConflict() &&
+ !RHS.hasConflict() && "Operand mismatch");
+ KnownBits WideLHS = LHS.sext(2 * BitWidth);
+ KnownBits WideRHS = RHS.sext(2 * BitWidth);
+ return computeForMul(WideLHS, WideRHS).extractBits(BitWidth, BitWidth);
+}
+
+KnownBits KnownBits::mulhu(const KnownBits &LHS, const KnownBits &RHS) {
+ unsigned BitWidth = LHS.getBitWidth();
+ assert(BitWidth == RHS.getBitWidth() && !LHS.hasConflict() &&
+ !RHS.hasConflict() && "Operand mismatch");
+ KnownBits WideLHS = LHS.zext(2 * BitWidth);
+ KnownBits WideRHS = RHS.zext(2 * BitWidth);
+ return computeForMul(WideLHS, WideRHS).extractBits(BitWidth, BitWidth);
+}
+
KnownBits KnownBits::udiv(const KnownBits &LHS, const KnownBits &RHS) {
unsigned BitWidth = LHS.getBitWidth();
assert(!LHS.hasConflict() && !RHS.hasConflict());
KnownBits KnownSMax(KnownAnd);
KnownBits KnownSMin(KnownAnd);
KnownBits KnownMul(KnownAnd);
+ KnownBits KnownMulHS(KnownAnd);
+ KnownBits KnownMulHU(KnownAnd);
KnownBits KnownUDiv(KnownAnd);
KnownBits KnownURem(KnownAnd);
KnownBits KnownSRem(KnownAnd);
KnownMul.One &= Res;
KnownMul.Zero &= ~Res;
+ Res = (N1.sext(2 * Bits) * N2.sext(2 * Bits)).extractBits(Bits, Bits);
+ KnownMulHS.One &= Res;
+ KnownMulHS.Zero &= ~Res;
+
+ Res = (N1.zext(2 * Bits) * N2.zext(2 * Bits)).extractBits(Bits, Bits);
+ KnownMulHU.One &= Res;
+ KnownMulHU.Zero &= ~Res;
+
if (!N2.isNullValue()) {
Res = N1.udiv(N2);
KnownUDiv.One &= Res;
EXPECT_EQ(KnownSMin.Zero, ComputedSMin.Zero);
EXPECT_EQ(KnownSMin.One, ComputedSMin.One);
- // ComputedMul is conservatively correct, but not guaranteed to be
+ // The following are conservatively correct, but not guaranteed to be
// precise.
KnownBits ComputedMul = KnownBits::computeForMul(Known1, Known2);
EXPECT_TRUE(ComputedMul.Zero.isSubsetOf(KnownMul.Zero));
EXPECT_TRUE(ComputedMul.One.isSubsetOf(KnownMul.One));
+ KnownBits ComputedMulHS = KnownBits::mulhs(Known1, Known2);
+ EXPECT_TRUE(ComputedMulHS.Zero.isSubsetOf(KnownMulHS.Zero));
+ EXPECT_TRUE(ComputedMulHS.One.isSubsetOf(KnownMulHS.One));
+
+ KnownBits ComputedMulHU = KnownBits::mulhu(Known1, Known2);
+ EXPECT_TRUE(ComputedMulHU.Zero.isSubsetOf(KnownMulHU.Zero));
+ EXPECT_TRUE(ComputedMulHU.One.isSubsetOf(KnownMulHU.One));
+
KnownBits ComputedUDiv = KnownBits::udiv(Known1, Known2);
EXPECT_TRUE(ComputedUDiv.Zero.isSubsetOf(KnownUDiv.Zero));
EXPECT_TRUE(ComputedUDiv.One.isSubsetOf(KnownUDiv.One));