Merge pull request #271 from plasmacel/master

fast branchless sign function #271
This commit is contained in:
Christophe Riccio 2014-11-20 23:37:37 +01:00
commit fe20b216a0

View File

@ -151,22 +151,15 @@ namespace detail
}
// sign
//Try something like based on x >> 31 to get the sign bit
// fast and works for any type
template <typename genFIType>
GLM_FUNC_QUALIFIER genFIType sign(genFIType x)
{
GLM_STATIC_ASSERT(
std::numeric_limits<genFIType>::is_iec559 ||
(std::numeric_limits<genFIType>::is_signed && std::numeric_limits<genFIType>::is_integer), "'sign' only accept signed inputs");
genFIType result;
if(x > genFIType(0))
result = genFIType(1);
else if(x < genFIType(0))
result = genFIType(-1);
else
result = genFIType(0);
return result;
return genFIType(genFIType(0) < x) - (x < genFIType(0));
}
template <typename T, precision P, template <typename, precision> class vecType>