Re: different alpha cpu compatibility issues?

[Jay Estabrook <Jay Estabrook compaq com>]

On Tue, Mar 28, 2000 at 02:59:45PM -0500, Eric Ding wrote:
>  
> OK, so here's the followup question -- how to compile specifically for EV4?

As the self-documenting features of Alpha GCC are a bit sparse (:-),
you could look at what the Makefile does for generating a "generic"
kernel for Alpha; ie arch/alpha/Makefile. I believe it is something
like:

  ifeq ($(CONFIG_ALPHA_GENERIC),y)
    CFLAGS := $(CFLAGS) -mcpu=ev5
  endif

Currently, the other options for -mcpu are:

	ev4		for AVANTI, NONAME, MULTIA, etc
	ev56		for PC164, LX164, MIATA, 
	pca56		for SX164, RX164
	ev6		for DP264, DS10, DS20, ES40, XP1000

ev4 and ev5 differ only in the scheduling of instructions.

ev56 adds byte/word operations.  pca56 adds the so-called MVI
instructions (ie analogous to MMX) ev6 adds addition FP instructions,
and probably some scheduling changes.  In the future, perhaps ev67
will add the counting instructions (I think Richard already did code
generation to use them, but it's not active).

--Jay++

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Jay A Estabrook                            Alpha Engineering - LINUX Project
Compaq Computer Corp. - MRO1-2/K20         (508) 467-2080
200 Forest Street, Marlboro MA 01752       Jay.Estabrook@compaq.com
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