[fpc-devel] Win64 FPC is in wrong download location
Michael Van Canneyt
michael at freepascal.org
Tue May 4 14:58:53 CEST 2010
On Tue, 4 May 2010, Jonas Maebe wrote:
>
> On 04 May 2010, at 12:51, Michael Van Canneyt wrote:
>
>> The i386 version of the compiler is simply much more optimized as the 64-bit
>> version (as are all FPC-generated binaries).
>
> That was true pre-2.4.0, but as of 2.4.0 the assembler optimiser is no longer enabled by default on i386 (and it didn't make that big of a difference in previous versions either). There are still some more peephole optimisations for i386, but I don't think the i386 code that FPC generates is that much more optimised than that for x86_64 at this point (or even PowerPC, for that matter).
>
> And as far as the speed of the compiler binary is concerned depending on whether it consists of i386 or x86_64 machine code (using -a -s so that the speed of the external assembler is not included):
>
> i386->i386 compiler compiling itself:
> user 0m8.180s
> sys 0m0.694s
>
> x86-64->i386 compiler compiling itself:
> user 0m8.096s
> sys 0m0.736s
>
> So at least on Mac OS X there is no real speed difference between the two.
Hm.
On Linux, there was a major difference between i386 and x64_64
compilers when running a "make cycle'. But I admit that my last
test was definitely from before 2.4.0.
Michael.
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