* Pointers to add doulle-float capabilities for the avr target
@ 2008-05-21 13:01 Tobias Frost
0 siblings, 0 replies; 5+ messages in thread
From: Tobias Frost @ 2008-05-21 13:01 UTC (permalink / raw)
To: gcc
Hallo,
I am currently evaluation the feasiblitiy to add (real) 64-doubles to the capabilities of the avr-gcc. The current state is, that the avr-gcc supports floats and alias them to doubles. However, a prospective project demands the resolution (accordung to their research), and therefore the company needing it might sponsor me to implement the support.
However, beside some trivial patches, I am not familiar with gcc hacking. Therefore it is hard for me to estimated how long this will take, but the numbers are cruicial to deside if I get the assignement.
As far as I dugg into the gcc source, there is a soft-float library which is used widely among non-FPU targets. However, I am currently missing the link, how the target has to be configured to be aware of that. As I am currently stuck with that, I'd appreciate any hint, link, documents etc which might point me into the right direction.
Thanks,
--
coldtobi
http://blog.coldtobi.de
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Pointers to add doulle-float capabilities for the avr target
2008-05-21 17:15 ` Tobias Frost
@ 2008-05-21 17:43 ` Uros Bizjak
0 siblings, 0 replies; 5+ messages in thread
From: Uros Bizjak @ 2008-05-21 17:43 UTC (permalink / raw)
To: Tobias Frost; +Cc: GCC
Tobias Frost wrote:
> Thanks a lot...
> This is almost the state I was when I left work today. I never thought,
> that will be sufficient ;-)
>
You will also need movdf (and perhaps pushdf) insn patterns in avr.md file.
Uros.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Pointers to add doulle-float capabilities for the avr target
@ 2008-05-21 17:26 hutchinsonandy
0 siblings, 0 replies; 5+ messages in thread
From: hutchinsonandy @ 2008-05-21 17:26 UTC (permalink / raw)
To: tofr, gcc; +Cc: ubizjak
That looks correct.
Be aware that support for handling long long operands (64 bits) - or
doubles is not well supported on AVR. So you may expose some problems
with this.
We currently have long long disabled in testsuite testing to avoid
noise. At some point I hope to switch it back on to see where we are -
but I have enough to deal with <64 bits a present.
Andy
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Pointers to add doulle-float capabilities for the avr target
2008-05-21 17:03 Uros Bizjak
@ 2008-05-21 17:15 ` Tobias Frost
2008-05-21 17:43 ` Uros Bizjak
0 siblings, 1 reply; 5+ messages in thread
From: Tobias Frost @ 2008-05-21 17:15 UTC (permalink / raw)
To: Uros Bizjak; +Cc: GCC
Thanks a lot...
This is almost the state I was when I left work today. I never thought,
that will be sufficient ;-)
I'll give feedback on Monday (tomorrow's holiday --> loooong weekend ;-)
Tobi
On Wed, 2008-05-21 at 19:02 +0200, Uros Bizjak wrote:
> Hello!
>
> > I am currently evaluation the feasiblitiy to add (real) 64-doubles to the capabilities of the avr-gcc. The current state is, that the avr-gcc supports floats and alias them to doubles. However, a prospective project demands the resolution (accordung to their research), and therefore the company needing it might sponsor me to implement the support.
> >
> > However, beside some trivial patches, I am not familiar with gcc hacking. Therefore it is hard for me to estimated how long this will take, but the numbers are cruicial to deside if I get the assignement.
> >
> > As far as I dugg into the gcc source, there is a soft-float library which is used widely among non-FPU targets. However, I am currently missing the link, how the target has to be configured to be aware of that. As I am currently stuck with that, I'd appreciate any hint, link, documents etc which might point me into the right direction.
> >
> >
>
> Add this code to avr/t-avr:
>
> --cut here--
> LIB2FUNCS_EXTRA = fp-bit.c dp-bit.c
>
> dp-bit.c: $(srcdir)/config/fp-bit.c
> cat $(srcdir)/config/fp-bit.c > dp-bit.c
>
> fp-bit.c: $(srcdir)/config/fp-bit.c
> echo '#define FLOAT' > fp-bit.c
> cat $(srcdir)/config/fp-bit.c >> fp-bit.c
> --cut here--
>
> then update avr/avr.h with
>
> #define FLOAT_TYPE_SIZE 32
> #define DOUBLE_TYPE_SIZE 64
> #define LONG_DOUBLE_TYPE_SIZE 64
>
> If everything works as expected, then you have just added soft-fp
> support to avr.
>
> Uros.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Pointers to add doulle-float capabilities for the avr target
@ 2008-05-21 17:03 Uros Bizjak
2008-05-21 17:15 ` Tobias Frost
0 siblings, 1 reply; 5+ messages in thread
From: Uros Bizjak @ 2008-05-21 17:03 UTC (permalink / raw)
To: GCC; +Cc: Tobias Frost
Hello!
> I am currently evaluation the feasiblitiy to add (real) 64-doubles to the capabilities of the avr-gcc. The current state is, that the avr-gcc supports floats and alias them to doubles. However, a prospective project demands the resolution (accordung to their research), and therefore the company needing it might sponsor me to implement the support.
>
> However, beside some trivial patches, I am not familiar with gcc hacking. Therefore it is hard for me to estimated how long this will take, but the numbers are cruicial to deside if I get the assignement.
>
> As far as I dugg into the gcc source, there is a soft-float library which is used widely among non-FPU targets. However, I am currently missing the link, how the target has to be configured to be aware of that. As I am currently stuck with that, I'd appreciate any hint, link, documents etc which might point me into the right direction.
>
>
Add this code to avr/t-avr:
--cut here--
LIB2FUNCS_EXTRA = fp-bit.c dp-bit.c
dp-bit.c: $(srcdir)/config/fp-bit.c
cat $(srcdir)/config/fp-bit.c > dp-bit.c
fp-bit.c: $(srcdir)/config/fp-bit.c
echo '#define FLOAT' > fp-bit.c
cat $(srcdir)/config/fp-bit.c >> fp-bit.c
--cut here--
then update avr/avr.h with
#define FLOAT_TYPE_SIZE 32
#define DOUBLE_TYPE_SIZE 64
#define LONG_DOUBLE_TYPE_SIZE 64
If everything works as expected, then you have just added soft-fp
support to avr.
Uros.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2008-05-21 13:01 Pointers to add doulle-float capabilities for the avr target Tobias Frost
2008-05-21 17:03 Uros Bizjak
2008-05-21 17:15 ` Tobias Frost
2008-05-21 17:43 ` Uros Bizjak
2008-05-21 17:26 hutchinsonandy
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