return IsNeg ? INT64_MIN : INT64_MAX;
return IsNeg ? -int64_t(U) : int64_t(U);
}
-
- static int compare(uint64_t L, uint64_t R, int Shift) {
- assert(Shift >= 0);
- assert(Shift < 64);
-
- uint64_t L_adjusted = L >> Shift;
- if (L_adjusted < R)
- return -1;
- if (L_adjusted > R)
- return 1;
-
- return L > L_adjusted << Shift ? 1 : 0;
- }
};
/// \brief Simple representation of an unsigned floating point.
return joinSigned(scaleByInverse(Unsigned.first), Unsigned.second);
}
- int compare(const UnsignedFloat &X) const;
+ int compare(const UnsignedFloat &X) const {
+ return ScaledNumbers::compare(Digits, Exponent, X.Digits, X.Exponent);
+ }
int compareTo(uint64_t N) const {
UnsignedFloat Float = getFloat(N);
int Compare = compare(Float);
return;
}
-template <class DigitsT>
-int UnsignedFloat<DigitsT>::compare(const UnsignedFloat &X) const {
- // Check for zero.
- if (isZero())
- return X.isZero() ? 0 : -1;
- if (X.isZero())
- return 1;
-
- // Check for the scale. Use lgFloor to be sure that the exponent difference
- // is always lower than 64.
- int32_t lgL = lgFloor(), lgR = X.lgFloor();
- if (lgL != lgR)
- return lgL < lgR ? -1 : 1;
-
- // Compare digits.
- if (Exponent < X.Exponent)
- return UnsignedFloatBase::compare(Digits, X.Digits, X.Exponent - Exponent);
-
- return -UnsignedFloatBase::compare(X.Digits, Digits, Exponent - X.Exponent);
-}
-
template <class T> struct isPodLike<UnsignedFloat<T>> {
static const bool value = true;
};
return Lg.first + (Lg.second < 0);
}
+/// \brief Implementation for comparing scaled numbers.
+///
+/// Compare two 64-bit numbers with different scales. Given that the scale of
+/// \c L is higher than that of \c R by \c ScaleDiff, compare them. Return -1,
+/// 1, and 0 for less than, greater than, and equal, respectively.
+///
+/// \pre 0 <= ScaleDiff < 64.
+int compareImpl(uint64_t L, uint64_t R, int ScaleDiff);
+
+/// \brief Compare two scaled numbers.
+///
+/// Compare two scaled numbers. Returns 0 for equal, -1 for less than, and 1
+/// for greater than.
+template <class DigitsT>
+int compare(DigitsT LDigits, int16_t LScale, DigitsT RDigits, int16_t RScale) {
+ // Check for zero.
+ if (!LDigits)
+ return RDigits ? -1 : 0;
+ if (!RDigits)
+ return 1;
+
+ // Check for the scale. Use getLgFloor to be sure that the scale difference
+ // is always lower than 64.
+ int32_t lgL = getLgFloor(LDigits, LScale), lgR = getLgFloor(RDigits, RScale);
+ if (lgL != lgR)
+ return lgL < lgR ? -1 : 1;
+
+ // Compare digits.
+ if (LScale < RScale)
+ return compareImpl(LDigits, RDigits, RScale - LScale);
+
+ return -compareImpl(RDigits, LDigits, LScale - RScale);
+}
+
} // end namespace ScaledNumbers
} // end namespace llvm
EXPECT_EQ(INT32_MIN, getLgCeiling(UINT64_C(0), 1));
}
+TEST(ScaledNumberHelpersTest, Compare) {
+ EXPECT_EQ(0, compare(UINT32_C(0), 0, UINT32_C(0), 1));
+ EXPECT_EQ(0, compare(UINT32_C(0), 0, UINT32_C(0), -10));
+ EXPECT_EQ(0, compare(UINT32_C(0), 0, UINT32_C(0), 20));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(64), -3));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(32), -2));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(16), -1));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(8), 0));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(4), 1));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(2), 2));
+ EXPECT_EQ(0, compare(UINT32_C(8), 0, UINT32_C(1), 3));
+ EXPECT_EQ(-1, compare(UINT32_C(0), 0, UINT32_C(1), 3));
+ EXPECT_EQ(-1, compare(UINT32_C(7), 0, UINT32_C(1), 3));
+ EXPECT_EQ(-1, compare(UINT32_C(7), 0, UINT32_C(64), -3));
+ EXPECT_EQ(1, compare(UINT32_C(9), 0, UINT32_C(1), 3));
+ EXPECT_EQ(1, compare(UINT32_C(9), 0, UINT32_C(64), -3));
+ EXPECT_EQ(1, compare(UINT32_C(9), 0, UINT32_C(0), 0));
+
+ EXPECT_EQ(0, compare(UINT64_C(0), 0, UINT64_C(0), 1));
+ EXPECT_EQ(0, compare(UINT64_C(0), 0, UINT64_C(0), -10));
+ EXPECT_EQ(0, compare(UINT64_C(0), 0, UINT64_C(0), 20));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(64), -3));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(32), -2));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(16), -1));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(8), 0));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(4), 1));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(2), 2));
+ EXPECT_EQ(0, compare(UINT64_C(8), 0, UINT64_C(1), 3));
+ EXPECT_EQ(-1, compare(UINT64_C(0), 0, UINT64_C(1), 3));
+ EXPECT_EQ(-1, compare(UINT64_C(7), 0, UINT64_C(1), 3));
+ EXPECT_EQ(-1, compare(UINT64_C(7), 0, UINT64_C(64), -3));
+ EXPECT_EQ(1, compare(UINT64_C(9), 0, UINT64_C(1), 3));
+ EXPECT_EQ(1, compare(UINT64_C(9), 0, UINT64_C(64), -3));
+ EXPECT_EQ(1, compare(UINT64_C(9), 0, UINT64_C(0), 0));
+ EXPECT_EQ(-1, compare(UINT64_MAX, 0, UINT64_C(1), 64));
+}
+
} // end namespace