On 04/05/12 18:07, Joseph Rushton Wakeling wrote:
On 03/05/12 16:59, Artur Skawina wrote:
There *was* a GDC bug some time ago, where a 'const' or 'in' function argument
prevented inlining. Iain fixed it, so unless an old GDC version is used, it's
probably not related.
I'm running GDC 4.6.3; I don't know if this fix made it into that release. It
would make sense if faulty inlining was responsible, though.
Let me clarify that last statement. The core function in the struct is one that
does something like this (pseudocode):
auto myMainFunc(Rating[] x)
{
do {
myFunc1(x);
myFunc2(x);
myFunc3(x);
/* calculate exit-condition value*/
} while (/* conditions not met */)
return results;
}
So, if I'm putting in const (or const ref) qualifiers, they're being applied to
the inputs of myMainFunc, myFunc1, myFunc2 and myFunc3. These 3 are obvious
candidates for compiler inlining, so anything which affects the possibility of
this happening could be expected to hit performance.
(... in the real code, myMainFunc() is called reputation(); the 3 interior
functions are respectively userDivergence(), userReputation() and
objectReputation().)
