> Surely it would be possible to use -ffixed-* options to reserve all the
> altivec registers and get precisely that effect?
Nah, I don't need to be that drastic. The RAID6 code is already in a
separate file that can have a specific additional set of compile flags,
so I can just enable altivec
Benjamin Herrenschmidt <[EMAIL PROTECTED]> writes:
> Unless -mcpu=POWER8 -mno-altivec -maltivec is legal ...
Yes, a later -msomething will override a previous -mno-something.
Original Message
>From: gcc-owner On Behalf Of David Edelsohn
>Sent: 27 February 2005 23:35
>> So what is the proper way or set of options for me to:
>
>> 1) optionally have POWER4 optimisations (that must be independant on the
>> rest below) 2) be able to use altivec instructions in ass
On Sun, 2005-02-27 at 19:32 -0500, David Edelsohn wrote:
> > Benjamin Herrenschmidt writes:
>
> Ben> The only problem I see is that the day we have a CPU, let's call it
> Ben> POWER8 for the sake of this demonstration, that has altivec and is
> Ben> different enough to justify a specific "opti
> Benjamin Herrenschmidt writes:
Ben> The only problem I see is that the day we have a CPU, let's call it
Ben> POWER8 for the sake of this demonstration, that has altivec and is
Ben> different enough to justify a specific "optimize" option, we'll have to
Ben> use -mcpu=POWER8 -mno-altivec for
On Sun, 2005-02-27 at 18:56 -0500, David Edelsohn wrote:
> > Benjamin Herrenschmidt writes:
>
> Ben> Ok. What I need is -mcpu=power4 -maltivec
>
> Sorry, no. -maltivec means generate Altivec code, not just enable
> Altivec instructions and registers. The above option is not different
On Feb 27, 2005, at 6:56 PM, David Edelsohn wrote:
Benjamin Herrenschmidt writes:
Ben> Ok. What I need is -mcpu=power4 -maltivec
Sorry, no. -maltivec means generate Altivec code, not just enable
Altivec instructions and registers. The above option is not different
than -mcpu=970. There i
> Benjamin Herrenschmidt writes:
Ben> Ok. What I need is -mcpu=power4 -maltivec
Sorry, no. -maltivec means generate Altivec code, not just enable
Altivec instructions and registers. The above option is not different
than -mcpu=970. There is no DWIM option.
David
On Sun, 2005-02-27 at 18:40 -0500, Andrew Pinski wrote:
> On Feb 27, 2005, at 6:35 PM, David Edelsohn wrote:
>
> > As Andrew Pinski mentioned, you also can use -mcpu=970
> > -mno-altivec. That should allow the assembler to accept Altivec
> > instructions, but GCC will not know about any Altiv
On Mon, Feb 28, 2005 at 10:00:42AM +1100, Benjamin Herrenschmidt wrote:
> Oh, and there are gcc version that will refuse -mcpu=power4 -maltivec so
> I can't even use -mcpu=power4 for the whole kernel and -maltivec just
> for the file containing the raid6 code
I guess what you mean here it that the
On Feb 27, 2005, at 6:35 PM, David Edelsohn wrote:
As Andrew Pinski mentioned, you also can use -mcpu=970
-mno-altivec. That should allow the assembler to accept Altivec
instructions, but GCC will not know about any Altivec registers for
inlined assembly parameters.
As I and Ben found out
> Oh, and there are gcc version that will refuse -mcpu=power4 -maltivec so
> I can't even use -mcpu=power4 for the whole kernel and -maltivec just
> for the file containing the raid6 code.
As Andrew Pinski mentioned, you also can use -mcpu=970
-mno-altivec. That should allow the assembler
> Yes, but as I wrote, that prevents building the RAID6 code which
> contains some selected altivec bits and cause gas to not get passed the
> proper option so we can have instructions like "dssall" in the low level
> assembly files.
>
> The later can probably be worked around by adding the prope
On Sun, 2005-02-27 at 17:53 -0500, David Edelsohn wrote:
> > Benjamin Herrenschmidt writes:
>
> Ben> There seem to be a problem with gcc 4.0 and implicit generation of
> Ben> altivec instructions when -mcpu=970.
>
> Ben> The problem is that the kernel cannot afford to use altivec instructions
> Benjamin Herrenschmidt writes:
Ben> There seem to be a problem with gcc 4.0 and implicit generation of
Ben> altivec instructions when -mcpu=970.
Ben> The problem is that the kernel cannot afford to use altivec instructions
Ben> (nor FPU) except in controlled environment. Specifically, thing
On Sun, 2005-02-27 at 17:47 -0500, Andrew Pinski wrote:
> s the proper way or set of options for me to:
> >
> > 1) optionally have POWER4 optimisations (that must be independant on
> > the rest below)
> > 2) be able to use altivec instructions in assembly
> > 3) be able to use altivec in a few s
On Feb 27, 2005, at 5:43 PM, Benjamin Herrenschmidt wrote:
Hi !
There seem to be a problem with gcc 4.0 and implicit generation of
altivec instructions when -mcpu=970.
The problem is that the kernel cannot afford to use altivec
instructions
(nor FPU) except in controlled environment. Specifically,
Hi !
There seem to be a problem with gcc 4.0 and implicit generation of
altivec instructions when -mcpu=970.
The problem is that the kernel cannot afford to use altivec instructions
(nor FPU) except in controlled environment. Specifically, things like
the RAID6 code has altivec (and SSE/2, which
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