Any chance for intel core --march?

Any chance for intel core --march?

[René Köcher]

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Is there any chance for a --march / --mcpu pair for intel core(duo)?

I'm currently running gentoo linux on a first generation mac book pro
equipped with a intel coreduo processor. Gentoo installation guide
states that --march=prescot is the best choice for my cpu.
But there are also some guides stating that --march=native would result
in better usage of the coreduo's features.

Left with this I was hoping for a intel core cpu-target in gcc 4.3
(which only seems to support core2..)

Is it even possible to fine tune for core(duo)?

Thank's in advance

René

(Sorry if this question was asked before - I searched the mailing-lists
and bugzilla without results.)


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Re: Any chance for intel core --march?

[Tim Prince]

René Köcher wrote:
> Is there any chance for a --march / --mcpu pair for intel core(duo)?
> 
> I'm currently running gentoo linux on a first generation mac book pro
> equipped with a intel coreduo processor. Gentoo installation guide
> states that --march=prescot is the best choice for my cpu.
> But there are also some guides stating that --march=native would result
> in better usage of the coreduo's features.
> 
> Left with this I was hoping for a intel core cpu-target in gcc 4.3
> (which only seems to support core2..)
> 
> Is it even possible to fine tune for core(duo)?
> 
-march=prescott was the answer for gcc-3.4 32-bit.  gcc-4.3 is well
tuned for Intel Core processors by default.  You may find cases
occasionally where prescott is faster.  As to tuning for the obsolete
core CPU (without the 2), the differences would be minor, perhaps some
cases where -funroll-loops would be less advantageous.

Re: Any chance for intel core --march?

[Ian Lance Taylor]

René Köcher <shirk87@gmail.com> writes:

> Is there any chance for a --march / --mcpu pair for intel core(duo)?

It's there in the development sources.  -march=core2.

It will be in the gcc 4.3.0 release.

Ian

Re: Any chance for intel core --march?

[Tim Prince]

Ian Lance Taylor wrote:
> René Köcher <shirk87@gmail.com> writes:
> 
>> Is there any chance for a --march / --mcpu pair for intel core(duo)?
> 
> It's there in the development sources.  -march=core2.
> 
> It will be in the gcc 4.3.0 release.
> 

Could OP be assured that it won't do anything incompatible with the
(obsolete) core duo (without the 2) which few of us ever saw ?