Re: gcc 2.8.0 seems OK here...

Robert Bihlmeyer (robbe@orcus.priv.at)
21 Mar 1998 10:47:22 +0100


Hi,

>>>>> On Fri, 20 Mar 1998 23:33:05 +0100 (CET)
>>>>> Marek Habersack <grendel@vip.maestro.com.pl> said:

Marek> On Fri, 20 Mar 1998, Niels Kristian Bech Jensen wrote:

>> The option -mpentium doesn't affect the instruction
>> scheduling. Those with problems have used -march=pentium (have you
>> tried that.)
Marek> Exatctly. The -mpentium flag merely instructs gcc to output
Marek> i586 opcodes, but the code isn't optimized any more than with
Marek> the usual -m486 (save for the opcodes, of course)

Contrariwise. From the gcc manual:

`-mcpu=CPU TYPE'
Assume the defaults for the machine type CPU TYPE when scheduling
instructions. The choices for CPU TYPE are: `i386', `i486',
`i586' (`pentium'), `pentium', `i686' (`pentiumpro') and
`pentiumpro'. While picking a specific CPU TYPE will schedule
things appropriately for that particular chip, the compiler will
not generate any code that does not run on the i386 without the
`-march=CPU TYPE' option being used.

`-march=CPU TYPE'
Generate instructions for the machine type CPU TYPE. The choices
for CPU TYPE are: `i386', `i486', `pentium', and `pentiumpro'.
Specifying `-march=CPU TYPE' implies `-mcpu=CPU TYPE'.

`-m386'
`-m486'
`-mpentium'
`-mpentiumpro'
Synonyms for -mcpu=i386, -mcpu=i486, -mcpu=pentium, and
-mcpu=pentiumpro respectively.

-- 
Robert Bihlmeyer	reads: Deutsch, English, MIME, Latin-1, NO SPAM!
<robbe@orcus.priv.at>	<http://stud2.tuwien.ac.at/~e9426626/sig.html>

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