Jeremie Pelletier wrote:
David Gileadi Wrote:
Daniel Keep wrote:
Jeremie Pelletier wrote:
If a function has both an asm and D implementations inside its body, and the D
version can be executed at compile time, but the asm one is much faster at
runtime. Is it possible to have the compiler use the D code path at compile
time (ie to fill in enums and whatnot), and have the asm version available at
runtime.
Not that I know of. There's no way to switch based on run time/compile
time. This was going to be solved, at least in part, using static
arguments, but that got dropped.
As it stands, you just have to use a suffix or prefix or something to
distinguish CTFE methods from runtime methods.
Is this a case for version(CompileTime){}?
No because it would also compile this block into the binary.
I think something like this might work:
static if (__traits(CompileTime)) {
... // ctfe code
} else {
asm {
...
}
}
Not sure what the exact syntax should be.
The easy way is of course to have different symbols for compile-time and
run-time. But this doesn't go well with generic programming where the function
needing such a check can be deep in the compile-time call stack.
For example:
int foo() { return bar + 1; }
int bar() { return foobar * 2; }
int foobar() {
static if(isCompileTime) return ...; /// asm cannot execute at compile time,
needed to keep foo and bar able to do CTFE
else asm { ...; } /// asm optimized for runtime
}
