Re: Doubt about formula transcription
"glen herrmannsfeldt" <gah@xxxxxxxxxxxxxxxx> wrote in message
news:EJCdnQm4nsIOW2banZ2dnUVZ_g2dnZ2d@xxxxxxxxxxxxxx
Those who need the speed should use the compiler optimization
options, and the compilers should then do it.
There's nothing guaranteed about what a compilers
will do when asked to optimise.
Nor is there any guarantee what compilers
will optimise even when not asked to optimise.
It use to be somewhat important in very old machines
having limited speed or memory capacity,
when the extra time taken (to produce an optimised
program) was expensive.
But none of those things is important any more,
and the extra time taken is barely noticeable.
.
Relevant Pages
- Re: Shift Operation
... "Intelligent" compilers optimize division by the powers of 2 ... level language) support it, it is better to do it there itself. ... obviously can be extended to multiply operations too..like multiple by ... optimise, and where the compiler should optimise on your behalf. ... (comp.lang.c) - Re: Should function argument be changed in function body?
... >> only requires one extra line, it does require extra code. ... >Do all compilers optimise the unnecessary copying of function ... Clearly the answer to this is "no", because there are some compilers ... Reading email is like searching for food in the garbage, ... (comp.lang.c) - Re: speed of tests in loops
... > I have found that the Lahey and Compaq Visual Fortran compilers will ... aggressively optimise loop-invariant code. ... VAX Fortran code always did ... was optimising a loop invariant that I'd previously not noticed. ... (comp.lang.fortran) - Re: C99 exact width integers usage - informal survey
... You might declare it an "int" on an 8-bit micro, but the compiler will optimise it to a smaller size if that is valid. ... There are compilers, though, that assign an enum to a byte if that would contain all the contained enumeration constants. ... (comp.arch.embedded) - Re: C99 exact width integers usage - informal survey
... You might declare it an ... but the compiler will optimise it to ... Are there compilers that make that level of optimization? ... redefining whole variable declarations. ... (comp.arch.embedded) |
|