Re: minmax(a,b,c) - Grupy dyskusyjne w eGospodarka.pl

eGospodarka.pl › Grupy › pl.comp.programming › minmax(a,b,c) › Re: minmax(a,b,c)

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Date: Wed, 4 Dec 2013 14:16:27 -0800 (PST)
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Subject: Re: minmax(a,b,c)
From: Wojciech Muła <w...@g...com>
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On Wednesday, December 4, 2013 10:09:28 PM UTC+1, bartekltg wrote:
> ciało funkcji:
> cmp edx, r8d
> jge SHORT $LN7@minmax3
> mov eax, edx //WTF
> mov edx, r8d //tu było swap(a,b)
> mov r8d, eax //czemu nie po prostu xchg?
>
> $LN7@minmax3:
>
> cmp r9d, edx
> jle SHORT $LN3@minmax3
> mov edx, r9d
> mov DWORD PTR [rcx+4], r8d
> mov rax, rcx
> mov DWORD PTR [rcx], edx
>

Bez sensu te skoki. Porządny kompilator uprości to do przesłań
warunkowych, bo na nowszych architekturach będzie szybsze od skoków.

Nieliniowa zmiana przepływu sterowania to złoooo! :)

w.