* Enable libgcc floating point emulation routines
@ 2020-10-21 20:27 William Tambe
2020-10-21 23:36 ` Jim Wilson
0 siblings, 1 reply; 6+ messages in thread
From: William Tambe @ 2020-10-21 20:27 UTC (permalink / raw)
To: gcc-help
For a specific platform, what is the proper way to enable the floating
point emulation routines described at ?
https://gcc.gnu.org/onlinedocs/gccint/Soft-float-library-routines.html#Soft-float-library-routines
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Enable libgcc floating point emulation routines
2020-10-21 20:27 Enable libgcc floating point emulation routines William Tambe
@ 2020-10-21 23:36 ` Jim Wilson
2020-10-22 2:48 ` William Tambe
0 siblings, 1 reply; 6+ messages in thread
From: Jim Wilson @ 2020-10-21 23:36 UTC (permalink / raw)
To: William Tambe; +Cc: gcc-help
On Wed, Oct 21, 2020 at 1:27 PM William Tambe via Gcc-help <
gcc-help@gcc.gnu.org> wrote:
> For a specific platform, what is the proper way to enable the floating
> point emulation routines described at ?
>
> https://gcc.gnu.org/onlinedocs/gccint/Soft-float-library-routines.html#Soft-float-library-routines
In libgcc/config.host, add one of the t-softfp* files to tmake_file for
your host. There are a number of choices, depending on exactly which modes
you need support for, and exactly which modes are implemented in hardware.
E.g. a target with no FP hardware and no 128-bit long double needs only
soft-float sf and df. A target with FP hardware that supports 32-bit float
only, and supports 128-bit long double, needs soft-float df and tf. Etc.
See the various target independent and target dependent t-softfp files and
pick one that matches your situation.
Jim
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Enable libgcc floating point emulation routines
2020-10-21 23:36 ` Jim Wilson
@ 2020-10-22 2:48 ` William Tambe
2020-10-22 3:40 ` William Tambe
2020-10-23 19:33 ` Jim Wilson
0 siblings, 2 replies; 6+ messages in thread
From: William Tambe @ 2020-10-22 2:48 UTC (permalink / raw)
To: Jim Wilson; +Cc: gcc-help
On Wed, Oct 21, 2020 at 6:36 PM Jim Wilson <jimw@sifive.com> wrote:
>
> On Wed, Oct 21, 2020 at 1:27 PM William Tambe via Gcc-help <gcc-help@gcc.gnu.org> wrote:
>>
>> For a specific platform, what is the proper way to enable the floating
>> point emulation routines described at ?
>> https://gcc.gnu.org/onlinedocs/gccint/Soft-float-library-routines.html#Soft-float-library-routines
>
>
> In libgcc/config.host, add one of the t-softfp* files to tmake_file for your host. There are a number of choices, depending on exactly which modes you need support for, and exactly which modes are implemented in hardware. E.g. a target with no FP hardware and no 128-bit long double needs only soft-float sf and df. A target with FP hardware that supports 32-bit float only, and supports 128-bit long double, needs soft-float df and tf. Etc. See the various target independent and target dependent t-softfp files and pick one that matches your situation.
In libgcc/config.host we currently have:
tmake_file="${tmake_file} t-softfp-sfdf t-softfp-excl t-softfp"
However, compiling a program that uses __mulsf3() throws the following error:
error: implicit declaration of function ‘__mulsf3’; did you mean
‘__mulsc3’? [-Werror=implicit-function-declaration]
Compilation is done using -nostdlib -lgcc
Any idea what else is missing ?
>
> Jim
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Enable libgcc floating point emulation routines
2020-10-22 2:48 ` William Tambe
@ 2020-10-22 3:40 ` William Tambe
2020-10-23 19:34 ` Jim Wilson
2020-10-23 19:33 ` Jim Wilson
1 sibling, 1 reply; 6+ messages in thread
From: William Tambe @ 2020-10-22 3:40 UTC (permalink / raw)
To: Jim Wilson; +Cc: gcc-help
On Wed, Oct 21, 2020 at 9:48 PM William Tambe <tambewilliam@gmail.com> wrote:
>
> On Wed, Oct 21, 2020 at 6:36 PM Jim Wilson <jimw@sifive.com> wrote:
> >
> > On Wed, Oct 21, 2020 at 1:27 PM William Tambe via Gcc-help <gcc-help@gcc.gnu.org> wrote:
> >>
> >> For a specific platform, what is the proper way to enable the floating
> >> point emulation routines described at ?
> >> https://gcc.gnu.org/onlinedocs/gccint/Soft-float-library-routines.html#Soft-float-library-routines
> >
> >
> > In libgcc/config.host, add one of the t-softfp* files to tmake_file for your host. There are a number of choices, depending on exactly which modes you need support for, and exactly which modes are implemented in hardware. E.g. a target with no FP hardware and no 128-bit long double needs only soft-float sf and df. A target with FP hardware that supports 32-bit float only, and supports 128-bit long double, needs soft-float df and tf. Etc. See the various target independent and target dependent t-softfp files and pick one that matches your situation.
>
> In libgcc/config.host we currently have:
> tmake_file="${tmake_file} t-softfp-sfdf t-softfp-excl t-softfp"
I ended up using:
tmake_file="${tmake_file} t-fpbit"
and it worked.
What is the difference between t-fpbit and t-softfp* ?
>
> However, compiling a program that uses __mulsf3() throws the following error:
> error: implicit declaration of function ‘__mulsf3’; did you mean
> ‘__mulsc3’? [-Werror=implicit-function-declaration]
>
> Compilation is done using -nostdlib -lgcc
>
> Any idea what else is missing ?
>
> >
> > Jim
> >
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Enable libgcc floating point emulation routines
2020-10-22 2:48 ` William Tambe
2020-10-22 3:40 ` William Tambe
@ 2020-10-23 19:33 ` Jim Wilson
1 sibling, 0 replies; 6+ messages in thread
From: Jim Wilson @ 2020-10-23 19:33 UTC (permalink / raw)
To: William Tambe; +Cc: gcc-help
On Wed, Oct 21, 2020 at 7:48 PM William Tambe <tambewilliam@gmail.com>
wrote:
> However, compiling a program that uses __mulsf3() throws the following
> error:
> error: implicit declaration of function ‘__mulsf3’; did you mean
> ‘__mulsc3’? [-Werror=implicit-function-declaration]
>
__mulsf3 isn't a user visible function. Instead of trying to call it, use
the '*' multiply operator and the compiler will call it for you.
Jim
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Enable libgcc floating point emulation routines
2020-10-22 3:40 ` William Tambe
@ 2020-10-23 19:34 ` Jim Wilson
0 siblings, 0 replies; 6+ messages in thread
From: Jim Wilson @ 2020-10-23 19:34 UTC (permalink / raw)
To: William Tambe; +Cc: gcc-help
On Wed, Oct 21, 2020 at 8:41 PM William Tambe <tambewilliam@gmail.com>
wrote:
> What is the difference between t-fpbit and t-softfp* ?
t-fpbit is for 8-bit targets that support float but not double.
Jim
^ permalink raw reply [flat|nested] 6+ messages in thread
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2020-10-21 20:27 Enable libgcc floating point emulation routines William Tambe
2020-10-21 23:36 ` Jim Wilson
2020-10-22 2:48 ` William Tambe
2020-10-22 3:40 ` William Tambe
2020-10-23 19:34 ` Jim Wilson
2020-10-23 19:33 ` Jim Wilson
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