> -----Original Message-----
> From: gcc-owner On Behalf Of Jonathan Wakely
> Sent: 11 February 2005 16:34
> On Fri, Feb 11, 2005 at 04:38:03PM +0100, Sam Lauber wrote:
>
> > I think Intel's confusing numbering system has confused
> > you. All ix86 processors, if the expression
> > x in first ix86 < x in second ix86
> > holds true, then second ix86 is compatible. The i586 is
> > NOT the Pentium.
>
> So why does the GCC manual say that -mtune=pentium is equivalent to
> -mtune=i586 ?
In terms of general terminology, it works like this.
'Pentium' refers to one cpu and one cpu only: the one introduced by Intel
after the '486.
i586 refers to all roughly-pentium-equivalent processors of that generation:
the Pentium itself, the AMD K5, the Cyrix 586, etc.
Likewise for i686 and Pentium Pro / K6 / Cyrix 686, etc.
As to whether gcc uses the terms with precision, I cannot comment. But I
would guess that the reason the two -mtune settings are the same is because
gcc's scheduling and codegen decisions are not specialised for individual
processors in the i586 category, but are generic to all of them.
cheers,
DaveK
--
Can't think of a witty .sigline today....
