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-rw-r--r--absl/numeric/int128.h128
1 files changed, 69 insertions, 59 deletions
diff --git a/absl/numeric/int128.h b/absl/numeric/int128.h
index a9cbe489..c7ad96be 100644
--- a/absl/numeric/int128.h
+++ b/absl/numeric/int128.h
@@ -586,10 +586,10 @@ inline uint128& uint128::operator=(int128 v) {
// Arithmetic operators.
-uint128 operator<<(uint128 lhs, int amount);
-uint128 operator>>(uint128 lhs, int amount);
-uint128 operator+(uint128 lhs, uint128 rhs);
-uint128 operator-(uint128 lhs, uint128 rhs);
+constexpr uint128 operator<<(uint128 lhs, int amount);
+constexpr uint128 operator>>(uint128 lhs, int amount);
+constexpr uint128 operator+(uint128 lhs, uint128 rhs);
+constexpr uint128 operator-(uint128 lhs, uint128 rhs);
uint128 operator*(uint128 lhs, uint128 rhs);
uint128 operator/(uint128 lhs, uint128 rhs);
uint128 operator%(uint128 lhs, uint128 rhs);
@@ -786,7 +786,7 @@ inline uint128::operator long double() const {
// Comparison operators.
-inline bool operator==(uint128 lhs, uint128 rhs) {
+constexpr bool operator==(uint128 lhs, uint128 rhs) {
#if defined(ABSL_HAVE_INTRINSIC_INT128)
return static_cast<unsigned __int128>(lhs) ==
static_cast<unsigned __int128>(rhs);
@@ -796,11 +796,9 @@ inline bool operator==(uint128 lhs, uint128 rhs) {
#endif
}
-inline bool operator!=(uint128 lhs, uint128 rhs) {
- return !(lhs == rhs);
-}
+constexpr bool operator!=(uint128 lhs, uint128 rhs) { return !(lhs == rhs); }
-inline bool operator<(uint128 lhs, uint128 rhs) {
+constexpr bool operator<(uint128 lhs, uint128 rhs) {
#ifdef ABSL_HAVE_INTRINSIC_INT128
return static_cast<unsigned __int128>(lhs) <
static_cast<unsigned __int128>(rhs);
@@ -811,11 +809,11 @@ inline bool operator<(uint128 lhs, uint128 rhs) {
#endif
}
-inline bool operator>(uint128 lhs, uint128 rhs) { return rhs < lhs; }
+constexpr bool operator>(uint128 lhs, uint128 rhs) { return rhs < lhs; }
-inline bool operator<=(uint128 lhs, uint128 rhs) { return !(rhs < lhs); }
+constexpr bool operator<=(uint128 lhs, uint128 rhs) { return !(rhs < lhs); }
-inline bool operator>=(uint128 lhs, uint128 rhs) { return !(lhs < rhs); }
+constexpr bool operator>=(uint128 lhs, uint128 rhs) { return !(lhs < rhs); }
// Unary operators.
@@ -827,14 +825,13 @@ constexpr inline int128 operator+(int128 val) {
return val;
}
-inline uint128 operator-(uint128 val) {
+constexpr uint128 operator-(uint128 val) {
#if defined(ABSL_HAVE_INTRINSIC_INT128)
return -static_cast<unsigned __int128>(val);
#else
- uint64_t hi = ~Uint128High64(val);
- uint64_t lo = ~Uint128Low64(val) + 1;
- if (lo == 0) ++hi; // carry
- return MakeUint128(hi, lo);
+ return MakeUint128(
+ ~Uint128High64(val) + static_cast<unsigned long>(Uint128Low64(val) == 0),
+ ~Uint128Low64(val) + 1);
#endif
}
@@ -903,67 +900,77 @@ inline uint128& uint128::operator^=(uint128 other) {
// Arithmetic operators.
-inline uint128 operator<<(uint128 lhs, int amount) {
+constexpr uint128 operator<<(uint128 lhs, int amount) {
#ifdef ABSL_HAVE_INTRINSIC_INT128
return static_cast<unsigned __int128>(lhs) << amount;
#else
// uint64_t shifts of >= 64 are undefined, so we will need some
// special-casing.
- if (amount < 64) {
- if (amount != 0) {
- return MakeUint128(
- (Uint128High64(lhs) << amount) | (Uint128Low64(lhs) >> (64 - amount)),
- Uint128Low64(lhs) << amount);
- }
- return lhs;
- }
- return MakeUint128(Uint128Low64(lhs) << (amount - 64), 0);
+ return amount >= 64 ? MakeUint128(Uint128Low64(lhs) << (amount - 64), 0)
+ : amount == 0 ? lhs
+ : MakeUint128((Uint128High64(lhs) << amount) |
+ (Uint128Low64(lhs) >> (64 - amount)),
+ Uint128Low64(lhs) << amount);
#endif
}
-inline uint128 operator>>(uint128 lhs, int amount) {
+constexpr uint128 operator>>(uint128 lhs, int amount) {
#ifdef ABSL_HAVE_INTRINSIC_INT128
return static_cast<unsigned __int128>(lhs) >> amount;
#else
// uint64_t shifts of >= 64 are undefined, so we will need some
// special-casing.
- if (amount < 64) {
- if (amount != 0) {
- return MakeUint128(Uint128High64(lhs) >> amount,
- (Uint128Low64(lhs) >> amount) |
- (Uint128High64(lhs) << (64 - amount)));
- }
- return lhs;
- }
- return MakeUint128(0, Uint128High64(lhs) >> (amount - 64));
+ return amount >= 64 ? MakeUint128(0, Uint128High64(lhs) >> (amount - 64))
+ : amount == 0 ? lhs
+ : MakeUint128(Uint128High64(lhs) >> amount,
+ (Uint128Low64(lhs) >> amount) |
+ (Uint128High64(lhs) << (64 - amount)));
#endif
}
-inline uint128 operator+(uint128 lhs, uint128 rhs) {
+#if !defined(ABSL_HAVE_INTRINSIC_INT128)
+namespace int128_internal {
+constexpr uint128 AddResult(uint128 result, uint128 lhs) {
+ // check for carry
+ return (Uint128Low64(result) < Uint128Low64(lhs))
+ ? MakeUint128(Uint128High64(result) + 1, Uint128Low64(result))
+ : result;
+}
+} // namespace int128_internal
+#endif
+
+constexpr uint128 operator+(uint128 lhs, uint128 rhs) {
#if defined(ABSL_HAVE_INTRINSIC_INT128)
return static_cast<unsigned __int128>(lhs) +
static_cast<unsigned __int128>(rhs);
#else
- uint128 result = MakeUint128(Uint128High64(lhs) + Uint128High64(rhs),
- Uint128Low64(lhs) + Uint128Low64(rhs));
- if (Uint128Low64(result) < Uint128Low64(lhs)) { // check for carry
- return MakeUint128(Uint128High64(result) + 1, Uint128Low64(result));
- }
- return result;
+ return int128_internal::AddResult(
+ MakeUint128(Uint128High64(lhs) + Uint128High64(rhs),
+ Uint128Low64(lhs) + Uint128Low64(rhs)),
+ lhs);
#endif
}
-inline uint128 operator-(uint128 lhs, uint128 rhs) {
+#if !defined(ABSL_HAVE_INTRINSIC_INT128)
+namespace int128_internal {
+constexpr uint128 SubstructResult(uint128 result, uint128 lhs, uint128 rhs) {
+ // check for carry
+ return (Uint128Low64(lhs) < Uint128Low64(rhs))
+ ? MakeUint128(Uint128High64(result) - 1, Uint128Low64(result))
+ : result;
+}
+} // namespace int128_internal
+#endif
+
+constexpr uint128 operator-(uint128 lhs, uint128 rhs) {
#if defined(ABSL_HAVE_INTRINSIC_INT128)
return static_cast<unsigned __int128>(lhs) -
static_cast<unsigned __int128>(rhs);
#else
- uint128 result = MakeUint128(Uint128High64(lhs) - Uint128High64(rhs),
- Uint128Low64(lhs) - Uint128Low64(rhs));
- if (Uint128Low64(lhs) < Uint128Low64(rhs)) { // check for carry
- return MakeUint128(Uint128High64(result) - 1, Uint128Low64(result));
- }
- return result;
+ return int128_internal::SubstructResult(
+ MakeUint128(Uint128High64(lhs) - Uint128High64(rhs),
+ Uint128Low64(lhs) - Uint128Low64(rhs)),
+ lhs, rhs);
#endif
}
@@ -1063,17 +1070,17 @@ inline int128& int128::operator=(unsigned long long v) {
}
// Arithmetic operators.
-
-int128 operator+(int128 lhs, int128 rhs);
-int128 operator-(int128 lhs, int128 rhs);
+constexpr int128 operator-(int128 v);
+constexpr int128 operator+(int128 lhs, int128 rhs);
+constexpr int128 operator-(int128 lhs, int128 rhs);
int128 operator*(int128 lhs, int128 rhs);
int128 operator/(int128 lhs, int128 rhs);
int128 operator%(int128 lhs, int128 rhs);
-int128 operator|(int128 lhs, int128 rhs);
-int128 operator&(int128 lhs, int128 rhs);
-int128 operator^(int128 lhs, int128 rhs);
-int128 operator<<(int128 lhs, int amount);
-int128 operator>>(int128 lhs, int amount);
+constexpr int128 operator|(int128 lhs, int128 rhs);
+constexpr int128 operator&(int128 lhs, int128 rhs);
+constexpr int128 operator^(int128 lhs, int128 rhs);
+constexpr int128 operator<<(int128 lhs, int amount);
+constexpr int128 operator>>(int128 lhs, int amount);
inline int128& int128::operator+=(int128 other) {
*this = *this + other;
@@ -1125,6 +1132,9 @@ inline int128& int128::operator>>=(int amount) {
return *this;
}
+// Forward declaration for comparison operators.
+constexpr bool operator!=(int128 lhs, int128 rhs);
+
namespace int128_internal {
// Casts from unsigned to signed while preserving the underlying binary
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-14 16:12:13 +0000