Fix handling of negative values

mborland · mborland · commit 5204fa20529e · 2025-07-03T14:54:00.000-04:00
diff --git a/include/boost/int128/numeric.hpp b/include/boost/int128/numeric.hpp
@@ -283,8 +283,7 @@ constexpr uint128_t gcd(uint128_t a, uint128_t b) noexcept
 
 constexpr int128_t gcd(const int128_t a, const int128_t b) noexcept
 {
-    const auto res {static_cast<int128_t>(gcd(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))))};
-    return (a < 0) != (b < 0) ? -res : res;
+    return static_cast<int128_t>(gcd(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))));
 }
 
 constexpr uint128_t lcm(const uint128_t a, const uint128_t b) noexcept
@@ -303,8 +302,7 @@ constexpr uint128_t lcm(const uint128_t a, const uint128_t b) noexcept
 
 constexpr int128_t lcm(const int128_t a, const int128_t b) noexcept
 {
-    const auto res {static_cast<int128_t>(lcm(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))))};
-    return (a < 0) != (b < 0) ? -res : res;
+    return static_cast<int128_t>(lcm(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))));
 }
 
 } // namespace int128

Original file line number	Diff line number	Diff line change
`@@ -283,8 +283,7 @@ constexpr uint128_t gcd(uint128_t a, uint128_t b) noexcept`
`283`	`283`
`284`	`284`	`constexpr int128_t gcd(const int128_t a, const int128_t b) noexcept`
`285`	`285`	`{`
`286`		`- const auto res {static_cast<int128_t>(gcd(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))))};`
`287`		`- return (a < 0) != (b < 0) ? -res : res;`
	`286`	`+ return static_cast<int128_t>(gcd(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))));`
`288`	`287`	`}`
`289`	`288`
`290`	`289`	`constexpr uint128_t lcm(const uint128_t a, const uint128_t b) noexcept`
`@@ -303,8 +302,7 @@ constexpr uint128_t lcm(const uint128_t a, const uint128_t b) noexcept`
`303`	`302`
`304`	`303`	`constexpr int128_t lcm(const int128_t a, const int128_t b) noexcept`
`305`	`304`	`{`
`306`		`- const auto res {static_cast<int128_t>(lcm(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))))};`
`307`		`- return (a < 0) != (b < 0) ? -res : res;`
	`305`	`+ return static_cast<int128_t>(lcm(static_cast<uint128_t>(abs(a)), static_cast<uint128_t>(abs(b))));`
`308`	`306`	`}`
`309`	`307`
`310`	`308`	`} // namespace int128`