Messages in this thread | | | Date | Sun, 7 Sep 2003 20:30:30 +0100 | From | Jamie Lokier <> | Subject | Re: nasm over gas? |
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Eric W. Biederman wrote: > Actually it is no as simple as that. With the instruction that uses > %edi following immediately after the instruction that populates it you cannot > execute those two instructions in parallel. So the code may be slower. The > exact rules depend on the architecture of the cpu.
I remember inserting a "nop" into a loop and it went significantly faster on a Pentium Pro :)
> If you concentrate on those handful of places where you need to > optimize that is reasonable. Beyond that there simply are not the > developer resources to do good assembly. And things like algorithmic > transformations in assembly are an absolute nightmare. Where they are > quite simple in C.
If we had enough developer resources to write the whole thing in good assembly, then for _sure_ we'd have enough to write a perfect compiler!
I would argue that the most powerful algorithmic transformations are a nightmare in C, too. Less so, though.
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