On 01/07/2012 12:37 AM, Jonathan M Davis wrote:
On Saturday, January 07, 2012 00:03:39 Alex Rønne Petersen wrote:
Most likely those functions are just implemented using inline assembly,
therefore not usable in CTFE.
Yeah, several functions in std.math use inline assembly. So, for them to be
able to be used at compile time, either the compiler must be expanded to be
able to run asm statements at compile time (which may or may not be planned
and may or may not be reasonable), or those functions need another branch
(using __cfte in an if condition) which doesn't use assembly. Or I suppose
that if the extra check for __ctfe isn't considered particularly acceptable
(after all, they're already using assembly) [snip.]
If the if condition is a constant, there is no runtime overhead.
