APInt APInt::smul_ov(const APInt &RHS, bool &Overflow) const {
APInt Res = *this * RHS;
- if (*this != 0 && RHS != 0)
- Overflow = Res.sdiv(RHS) != *this || Res.sdiv(*this) != RHS;
+ if (RHS != 0)
+ Overflow = Res.sdiv(RHS) != *this ||
+ (isMinSignedValue() && RHS.isAllOnes());
else
Overflow = false;
return Res;
for (unsigned Bits = 1; Bits <= 5; ++Bits)
for (unsigned A = 0; A != 1u << Bits; ++A)
for (unsigned B = 0; B != 1u << Bits; ++B) {
- APInt C = APInt(Bits, A).umul_ov(APInt(Bits, B), Overflow);
- APInt D = APInt(2 * Bits, A) * APInt(2 * Bits, B);
- EXPECT_TRUE(D.getHiBits(Bits).isNullValue() != Overflow);
+ APInt N1 = APInt(Bits, A), N2 = APInt(Bits, B);
+ APInt Narrow = N1.umul_ov(N2, Overflow);
+ APInt Wide = N1.zext(2 * Bits) * N2.zext(2 * Bits);
+ EXPECT_EQ(Wide.trunc(Bits), Narrow);
+ EXPECT_EQ(Narrow.zext(2 * Bits) != Wide, Overflow);
+ }
+}
+
+TEST(APIntTest, smul_ov) {
+ for (unsigned Bits = 1; Bits <= 5; ++Bits)
+ for (unsigned A = 0; A != 1u << Bits; ++A)
+ for (unsigned B = 0; B != 1u << Bits; ++B) {
+ bool Overflow;
+ APInt N1 = APInt(Bits, A), N2 = APInt(Bits, B);
+ APInt Narrow = N1.smul_ov(N2, Overflow);
+ APInt Wide = N1.sext(2 * Bits) * N2.sext(2 * Bits);
+ EXPECT_EQ(Wide.trunc(Bits), Narrow);
+ EXPECT_EQ(Narrow.sext(2 * Bits) != Wide, Overflow);
}
}