Patchwork Fix arm-netbsd build error

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Submitter Doug Evans via gdb-patches
Date Feb. 11, 2020, 10:55 p.m.
Message ID <20200211225503.32992-1-cbiesinger@google.com>
Download mbox | patch
Permalink /patch/37981/
State New
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Doug Evans via gdb-patches - Feb. 11, 2020, 10:55 p.m.
The floating point register interface has changed to this:
https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h

It now uses VFP instead of FPA registers. This patch updates
arm-nbsd-nat.c accordingly.

Tested by compiling on arm-netbsd on qemu. For actually testing, there
seems to be something missing as "info registers" only shows FPA
registers and no VFP ones. I am still investigating why this is;
please let me know if you know. However, I think this is still good
to check in as-is.

gdb/ChangeLog:

2020-02-11  Christian Biesinger  <cbiesinger@google.com>

	* arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
	(arm_supply_vfpregset): ...this, and update to use VFP registers.
	(fetch_fp_register): Update.
	(fetch_fp_regs): Update.
	(store_fp_register): Update.
	(store_fp_regs): Update.
	(fetch_elfcore_registers): Update.
---
 gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
 1 file changed, 34 insertions(+), 46 deletions(-)
Doug Evans via gdb-patches - Feb. 11, 2020, 11:34 p.m.
On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
<cbiesinger@google.com> wrote:
>
> The floating point register interface has changed to this:
> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
>
> It now uses VFP instead of FPA registers. This patch updates
> arm-nbsd-nat.c accordingly.
>
> Tested by compiling on arm-netbsd on qemu. For actually testing, there
> seems to be something missing as "info registers" only shows FPA
> registers and no VFP ones. I am still investigating why this is;
> please let me know if you know. However, I think this is still good
> to check in as-is.

Hm... this is perhaps because arm_netbsd_nat_target does not implement
read_description; if it returned arm_read_description
(ARM_FP_TYPE_VFPV2) this may work?

>
> gdb/ChangeLog:
>
> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
>
>         * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
>         (arm_supply_vfpregset): ...this, and update to use VFP registers.
>         (fetch_fp_register): Update.
>         (fetch_fp_regs): Update.
>         (store_fp_register): Update.
>         (store_fp_regs): Update.
>         (fetch_elfcore_registers): Update.
> ---
>  gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
>  1 file changed, 34 insertions(+), 46 deletions(-)
>
> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
> index 11afc289c3..8027f54dfe 100644
> --- a/gdb/arm-nbsd-nat.c
> +++ b/gdb/arm-nbsd-nat.c
> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
>  }
>
>  static void
> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
>  {
> -  int regno;
> -
> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> -    regcache->raw_supply (regno,
> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
> +  struct vfpreg &vfp = fpregset->fpr_vfp;
> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>
> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>  }
>
>  static void
> @@ -147,10 +145,10 @@ static void
>  fetch_fp_register (struct regcache *regcache, int regno)
>  {
>    struct fpreg inferior_fp_registers;
> -  int ret;
> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>
> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>
>    if (ret < 0)
>      {
> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
>        return;
>      }
>
> -  switch (regno)
> +  if (regno == ARM_FPSCR_REGNUM)
> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>      {
> -    case ARM_FPS_REGNUM:
> -      regcache->raw_supply (ARM_FPS_REGNUM,
> -                           (char *) &inferior_fp_registers.fpr_fpsr);
> -      break;
> -
> -    default:
> -      regcache->raw_supply
> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> -      break;
> +      regcache->raw_supply (regno,
> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>      }
> +  else
> +    warning (_("Invalid register number."));
>  }
>
>  static void
> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
>        return;
>      }
>
> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
>  }
>
>  void
> @@ -327,10 +322,9 @@ static void
>  store_fp_register (const struct regcache *regcache, int regno)
>  {
>    struct fpreg inferior_fp_registers;
> -  int ret;
> -
> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>
>    if (ret < 0)
>      {
> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
>        return;
>      }
>
> -  switch (regno)
> +  if (regno == ARM_FPSCR_REGNUM)
> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>      {
> -    case ARM_FPS_REGNUM:
> -      regcache->raw_collect (ARM_FPS_REGNUM,
> -                            (char *) &inferior_fp_registers.fpr_fpsr);
> -      break;
> -
> -    default:
> -      regcache->raw_collect
> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> -      break;
> +      regcache->raw_collect (regno,
> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>      }
> +  else
> +    warning (_("Invalid register number."));
>
>    ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>                 (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
>  static void
>  store_fp_regs (const struct regcache *regcache)
>  {
> -  struct fpreg inferior_fp_registers;
> -  int ret;
> -  int regno;
> +  struct fpreg fpregs;
>
> -
> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>      regcache->raw_collect
> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>
> -  regcache->raw_collect (ARM_FPS_REGNUM,
> -                        (char *) &inferior_fp_registers.fpr_fpsr);
> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
>
> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
>
>    if (ret < 0)
>      warning (_("unable to store floating-point registers"));
> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
>           /* The memcpy may be unnecessary, but we can't really be sure
>              of the alignment of the data in the core file.  */
>           memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
> -         arm_supply_fparegset (regcache, &fparegset);
> +         arm_supply_vfpregset (regcache, &fparegset);
>         }
>        break;
>
> --
> 2.25.0.225.g125e21ebc7-goog
>
Alan Hayward - Feb. 12, 2020, 1:29 p.m.
> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:

> 

> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger

> <cbiesinger@google.com> wrote:

>> 

>> The floating point register interface has changed to this:

>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h

>> 

>> It now uses VFP instead of FPA registers. This patch updates

>> arm-nbsd-nat.c accordingly.

>> 

>> Tested by compiling on arm-netbsd on qemu. For actually testing, there

>> seems to be something missing as "info registers" only shows FPA

>> registers and no VFP ones. I am still investigating why this is;

>> please let me know if you know. However, I think this is still good

>> to check in as-is.

> 

> Hm... this is perhaps because arm_netbsd_nat_target does not implement

> read_description; if it returned arm_read_description

> (ARM_FP_TYPE_VFPV2) this may work?

> 


Yes, looks like netbsd isn’t using any target description functionality.

I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
and then using the AUTO setting. But that’s just a guess.

Implementing read_description as you suggest should help. However,
read_description should probably do HWCAP checking similar to the
arm_linux_nat_target and arm_fbsd_nat_target versions.

Without that, I’d worry that your patch below might start writing off the
end of the regcache that had been allocated for a fewer number of registers.

>> 

>> gdb/ChangeLog:

>> 

>> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>

>> 

>>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...

>>        (arm_supply_vfpregset): ...this, and update to use VFP registers.

>>        (fetch_fp_register): Update.

>>        (fetch_fp_regs): Update.

>>        (store_fp_register): Update.

>>        (store_fp_regs): Update.

>>        (fetch_elfcore_registers): Update.

>> ---

>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------

>> 1 file changed, 34 insertions(+), 46 deletions(-)

>> 

>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c

>> index 11afc289c3..8027f54dfe 100644

>> --- a/gdb/arm-nbsd-nat.c

>> +++ b/gdb/arm-nbsd-nat.c

>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)

>> }

>> 

>> static void

>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)

>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)

>> {

>> -  int regno;

>> -

>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)

>> -    regcache->raw_supply (regno,

>> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);

>> +  struct vfpreg &vfp = fpregset->fpr_vfp;

>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)

>> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);

>> 

>> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);

>> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);

>> }

>> 

>> static void

>> @@ -147,10 +145,10 @@ static void

>> fetch_fp_register (struct regcache *regcache, int regno)

>> {

>>   struct fpreg inferior_fp_registers;

>> -  int ret;

>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),

>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);

>> 

>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),

>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);

>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;

>> 

>>   if (ret < 0)

>>     {

>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)

>>       return;

>>     }

>> 

>> -  switch (regno)

>> +  if (regno == ARM_FPSCR_REGNUM)

>> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);

>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)

>>     {

>> -    case ARM_FPS_REGNUM:

>> -      regcache->raw_supply (ARM_FPS_REGNUM,

>> -                           (char *) &inferior_fp_registers.fpr_fpsr);

>> -      break;

>> -

>> -    default:

>> -      regcache->raw_supply

>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);

>> -      break;

>> +      regcache->raw_supply (regno,

>> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);

>>     }

>> +  else

>> +    warning (_("Invalid register number."));

>> }

>> 

>> static void

>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)

>>       return;

>>     }

>> 

>> -  arm_supply_fparegset (regcache, &inferior_fp_registers);

>> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);

>> }

>> 

>> void

>> @@ -327,10 +322,9 @@ static void

>> store_fp_register (const struct regcache *regcache, int regno)

>> {

>>   struct fpreg inferior_fp_registers;

>> -  int ret;

>> -

>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),

>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);

>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),

>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);

>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;

>> 

>>   if (ret < 0)

>>     {

>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)

>>       return;

>>     }

>> 

>> -  switch (regno)

>> +  if (regno == ARM_FPSCR_REGNUM)

>> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);

>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)

>>     {

>> -    case ARM_FPS_REGNUM:

>> -      regcache->raw_collect (ARM_FPS_REGNUM,

>> -                            (char *) &inferior_fp_registers.fpr_fpsr);

>> -      break;

>> -

>> -    default:

>> -      regcache->raw_collect

>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);

>> -      break;

>> +      regcache->raw_collect (regno,

>> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);

>>     }

>> +  else

>> +    warning (_("Invalid register number."));

>> 

>>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),

>>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);

>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)

>> static void

>> store_fp_regs (const struct regcache *regcache)

>> {

>> -  struct fpreg inferior_fp_registers;

>> -  int ret;

>> -  int regno;

>> +  struct fpreg fpregs;

>> 

>> -

>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)

>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)

>>     regcache->raw_collect

>> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);

>> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);

>> 

>> -  regcache->raw_collect (ARM_FPS_REGNUM,

>> -                        (char *) &inferior_fp_registers.fpr_fpsr);

>> +  regcache->raw_collect (ARM_FPSCR_REGNUM,

>> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);

>> 

>> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),

>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);

>> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),

>> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);

>> 

>>   if (ret < 0)

>>     warning (_("unable to store floating-point registers"));

>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,

>>          /* The memcpy may be unnecessary, but we can't really be sure

>>             of the alignment of the data in the core file.  */

>>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));

>> -         arm_supply_fparegset (regcache, &fparegset);

>> +         arm_supply_vfpregset (regcache, &fparegset);

>>        }

>>       break;

>> 

>> --

>> 2.25.0.225.g125e21ebc7-goog

>>
Doug Evans via gdb-patches - Feb. 12, 2020, 4:28 p.m.
On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward <Alan.Hayward@arm.com> wrote:
>
>
>
> > On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:
> >
> > On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
> > <cbiesinger@google.com> wrote:
> >>
> >> The floating point register interface has changed to this:
> >> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
> >>
> >> It now uses VFP instead of FPA registers. This patch updates
> >> arm-nbsd-nat.c accordingly.
> >>
> >> Tested by compiling on arm-netbsd on qemu. For actually testing, there
> >> seems to be something missing as "info registers" only shows FPA
> >> registers and no VFP ones. I am still investigating why this is;
> >> please let me know if you know. However, I think this is still good
> >> to check in as-is.
> >
> > Hm... this is perhaps because arm_netbsd_nat_target does not implement
> > read_description; if it returned arm_read_description
> > (ARM_FP_TYPE_VFPV2) this may work?
> >
>
> Yes, looks like netbsd isn’t using any target description functionality.
>
> I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
> and then using the AUTO setting. But that’s just a guess.
>
> Implementing read_description as you suggest should help. However,
> read_description should probably do HWCAP checking similar to the
> arm_linux_nat_target and arm_fbsd_nat_target versions.
>
> Without that, I’d worry that your patch below might start writing off the
> end of the regcache that had been allocated for a fewer number of registers.

Hm... well, I've probably spent entirely too much time on this
already, but just in case there's an easy fix -- Kamil, does NetBSD
provide an API similar to Linux's HWCAP API that would let me check
which VFP version the current CPU is using? It seems AUXV does not
contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be
missing something.

(Compare arm_fbsd_read_description_auxv /
arm_linux_nat_target::read_description)

Christian

>
> >>
> >> gdb/ChangeLog:
> >>
> >> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
> >>
> >>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
> >>        (arm_supply_vfpregset): ...this, and update to use VFP registers.
> >>        (fetch_fp_register): Update.
> >>        (fetch_fp_regs): Update.
> >>        (store_fp_register): Update.
> >>        (store_fp_regs): Update.
> >>        (fetch_elfcore_registers): Update.
> >> ---
> >> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
> >> 1 file changed, 34 insertions(+), 46 deletions(-)
> >>
> >> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
> >> index 11afc289c3..8027f54dfe 100644
> >> --- a/gdb/arm-nbsd-nat.c
> >> +++ b/gdb/arm-nbsd-nat.c
> >> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
> >> }
> >>
> >> static void
> >> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
> >> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
> >> {
> >> -  int regno;
> >> -
> >> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> >> -    regcache->raw_supply (regno,
> >> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
> >> +  struct vfpreg &vfp = fpregset->fpr_vfp;
> >> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> >> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>
> >> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
> >> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> >> }
> >>
> >> static void
> >> @@ -147,10 +145,10 @@ static void
> >> fetch_fp_register (struct regcache *regcache, int regno)
> >> {
> >>   struct fpreg inferior_fp_registers;
> >> -  int ret;
> >> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>
> >> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
> >>
> >>   if (ret < 0)
> >>     {
> >> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
> >>       return;
> >>     }
> >>
> >> -  switch (regno)
> >> +  if (regno == ARM_FPSCR_REGNUM)
> >> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> >> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
> >>     {
> >> -    case ARM_FPS_REGNUM:
> >> -      regcache->raw_supply (ARM_FPS_REGNUM,
> >> -                           (char *) &inferior_fp_registers.fpr_fpsr);
> >> -      break;
> >> -
> >> -    default:
> >> -      regcache->raw_supply
> >> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> >> -      break;
> >> +      regcache->raw_supply (regno,
> >> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>     }
> >> +  else
> >> +    warning (_("Invalid register number."));
> >> }
> >>
> >> static void
> >> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
> >>       return;
> >>     }
> >>
> >> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
> >> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
> >> }
> >>
> >> void
> >> @@ -327,10 +322,9 @@ static void
> >> store_fp_register (const struct regcache *regcache, int regno)
> >> {
> >>   struct fpreg inferior_fp_registers;
> >> -  int ret;
> >> -
> >> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
> >>
> >>   if (ret < 0)
> >>     {
> >> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
> >>       return;
> >>     }
> >>
> >> -  switch (regno)
> >> +  if (regno == ARM_FPSCR_REGNUM)
> >> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> >> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
> >>     {
> >> -    case ARM_FPS_REGNUM:
> >> -      regcache->raw_collect (ARM_FPS_REGNUM,
> >> -                            (char *) &inferior_fp_registers.fpr_fpsr);
> >> -      break;
> >> -
> >> -    default:
> >> -      regcache->raw_collect
> >> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> >> -      break;
> >> +      regcache->raw_collect (regno,
> >> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>     }
> >> +  else
> >> +    warning (_("Invalid register number."));
> >>
> >>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> >>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
> >> static void
> >> store_fp_regs (const struct regcache *regcache)
> >> {
> >> -  struct fpreg inferior_fp_registers;
> >> -  int ret;
> >> -  int regno;
> >> +  struct fpreg fpregs;
> >>
> >> -
> >> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> >> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> >>     regcache->raw_collect
> >> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> >> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>
> >> -  regcache->raw_collect (ARM_FPS_REGNUM,
> >> -                        (char *) &inferior_fp_registers.fpr_fpsr);
> >> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
> >> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
> >>
> >> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> >> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> >> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
> >>
> >>   if (ret < 0)
> >>     warning (_("unable to store floating-point registers"));
> >> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
> >>          /* The memcpy may be unnecessary, but we can't really be sure
> >>             of the alignment of the data in the core file.  */
> >>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
> >> -         arm_supply_fparegset (regcache, &fparegset);
> >> +         arm_supply_vfpregset (regcache, &fparegset);
> >>        }
> >>       break;
> >>
> >> --
> >> 2.25.0.225.g125e21ebc7-goog
> >>
>
Kamil Rytarowski - Feb. 12, 2020, 5:09 p.m.
On 12.02.2020 17:28, Christian Biesinger wrote:
> On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward <Alan.Hayward@arm.com> wrote:
>>
>>
>>
>>> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:
>>>
>>> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
>>> <cbiesinger@google.com> wrote:
>>>>
>>>> The floating point register interface has changed to this:
>>>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
>>>>
>>>> It now uses VFP instead of FPA registers. This patch updates
>>>> arm-nbsd-nat.c accordingly.
>>>>
>>>> Tested by compiling on arm-netbsd on qemu. For actually testing, there
>>>> seems to be something missing as "info registers" only shows FPA
>>>> registers and no VFP ones. I am still investigating why this is;
>>>> please let me know if you know. However, I think this is still good
>>>> to check in as-is.
>>>
>>> Hm... this is perhaps because arm_netbsd_nat_target does not implement
>>> read_description; if it returned arm_read_description
>>> (ARM_FP_TYPE_VFPV2) this may work?
>>>
>>
>> Yes, looks like netbsd isn’t using any target description functionality.
>>
>> I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
>> and then using the AUTO setting. But that’s just a guess.
>>
>> Implementing read_description as you suggest should help. However,
>> read_description should probably do HWCAP checking similar to the
>> arm_linux_nat_target and arm_fbsd_nat_target versions.
>>
>> Without that, I’d worry that your patch below might start writing off the
>> end of the regcache that had been allocated for a fewer number of registers.
> 
> Hm... well, I've probably spent entirely too much time on this
> already, but just in case there's an easy fix -- Kamil, does NetBSD
> provide an API similar to Linux's HWCAP API that would let me check
> which VFP version the current CPU is using? It seems AUXV does not
> contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be
> missing something.
> 
> (Compare arm_fbsd_read_description_auxv /
> arm_linux_nat_target::read_description)
> 
> Christian
> 

Thank you for your work.

HWCAP in auxv is not supported (although there is a stub for it).

Here is a complete algorithm to detect FPU on ARM 32-bit.

http://netbsd.org/~kamil/arm-fpu.c

>>
>>>>
>>>> gdb/ChangeLog:
>>>>
>>>> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
>>>>
>>>>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
>>>>        (arm_supply_vfpregset): ...this, and update to use VFP registers.
>>>>        (fetch_fp_register): Update.
>>>>        (fetch_fp_regs): Update.
>>>>        (store_fp_register): Update.
>>>>        (store_fp_regs): Update.
>>>>        (fetch_elfcore_registers): Update.
>>>> ---
>>>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
>>>> 1 file changed, 34 insertions(+), 46 deletions(-)
>>>>
>>>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
>>>> index 11afc289c3..8027f54dfe 100644
>>>> --- a/gdb/arm-nbsd-nat.c
>>>> +++ b/gdb/arm-nbsd-nat.c
>>>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
>>>> }
>>>>
>>>> static void
>>>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
>>>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
>>>> {
>>>> -  int regno;
>>>> -
>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
>>>> -    regcache->raw_supply (regno,
>>>> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
>>>> +  struct vfpreg &vfp = fpregset->fpr_vfp;
>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>>>> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>
>>>> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
>>>> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>> }
>>>>
>>>> static void
>>>> @@ -147,10 +145,10 @@ static void
>>>> fetch_fp_register (struct regcache *regcache, int regno)
>>>> {
>>>>   struct fpreg inferior_fp_registers;
>>>> -  int ret;
>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>
>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>>>>
>>>>   if (ret < 0)
>>>>     {
>>>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
>>>>       return;
>>>>     }
>>>>
>>>> -  switch (regno)
>>>> +  if (regno == ARM_FPSCR_REGNUM)
>>>> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>>>>     {
>>>> -    case ARM_FPS_REGNUM:
>>>> -      regcache->raw_supply (ARM_FPS_REGNUM,
>>>> -                           (char *) &inferior_fp_registers.fpr_fpsr);
>>>> -      break;
>>>> -
>>>> -    default:
>>>> -      regcache->raw_supply
>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>> -      break;
>>>> +      regcache->raw_supply (regno,
>>>> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>     }
>>>> +  else
>>>> +    warning (_("Invalid register number."));
>>>> }
>>>>
>>>> static void
>>>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
>>>>       return;
>>>>     }
>>>>
>>>> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
>>>> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
>>>> }
>>>>
>>>> void
>>>> @@ -327,10 +322,9 @@ static void
>>>> store_fp_register (const struct regcache *regcache, int regno)
>>>> {
>>>>   struct fpreg inferior_fp_registers;
>>>> -  int ret;
>>>> -
>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>>>>
>>>>   if (ret < 0)
>>>>     {
>>>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
>>>>       return;
>>>>     }
>>>>
>>>> -  switch (regno)
>>>> +  if (regno == ARM_FPSCR_REGNUM)
>>>> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>>>>     {
>>>> -    case ARM_FPS_REGNUM:
>>>> -      regcache->raw_collect (ARM_FPS_REGNUM,
>>>> -                            (char *) &inferior_fp_registers.fpr_fpsr);
>>>> -      break;
>>>> -
>>>> -    default:
>>>> -      regcache->raw_collect
>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>> -      break;
>>>> +      regcache->raw_collect (regno,
>>>> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>     }
>>>> +  else
>>>> +    warning (_("Invalid register number."));
>>>>
>>>>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
>>>> static void
>>>> store_fp_regs (const struct regcache *regcache)
>>>> {
>>>> -  struct fpreg inferior_fp_registers;
>>>> -  int ret;
>>>> -  int regno;
>>>> +  struct fpreg fpregs;
>>>>
>>>> -
>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>>>>     regcache->raw_collect
>>>> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>
>>>> -  regcache->raw_collect (ARM_FPS_REGNUM,
>>>> -                        (char *) &inferior_fp_registers.fpr_fpsr);
>>>> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
>>>> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
>>>>
>>>> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
>>>>
>>>>   if (ret < 0)
>>>>     warning (_("unable to store floating-point registers"));
>>>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
>>>>          /* The memcpy may be unnecessary, but we can't really be sure
>>>>             of the alignment of the data in the core file.  */
>>>>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
>>>> -         arm_supply_fparegset (regcache, &fparegset);
>>>> +         arm_supply_vfpregset (regcache, &fparegset);
>>>>        }
>>>>       break;
>>>>
>>>> --
>>>> 2.25.0.225.g125e21ebc7-goog
>>>>
>>
Kamil Rytarowski - Feb. 12, 2020, 5:15 p.m.
On 12.02.2020 18:09, Kamil Rytarowski wrote:
> On 12.02.2020 17:28, Christian Biesinger wrote:
>> On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward <Alan.Hayward@arm.com> wrote:
>>>
>>>
>>>
>>>> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:
>>>>
>>>> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
>>>> <cbiesinger@google.com> wrote:
>>>>>
>>>>> The floating point register interface has changed to this:
>>>>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
>>>>>
>>>>> It now uses VFP instead of FPA registers. This patch updates
>>>>> arm-nbsd-nat.c accordingly.
>>>>>
>>>>> Tested by compiling on arm-netbsd on qemu. For actually testing, there
>>>>> seems to be something missing as "info registers" only shows FPA
>>>>> registers and no VFP ones. I am still investigating why this is;
>>>>> please let me know if you know. However, I think this is still good
>>>>> to check in as-is.
>>>>
>>>> Hm... this is perhaps because arm_netbsd_nat_target does not implement
>>>> read_description; if it returned arm_read_description
>>>> (ARM_FP_TYPE_VFPV2) this may work?
>>>>
>>>
>>> Yes, looks like netbsd isn’t using any target description functionality.
>>>
>>> I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
>>> and then using the AUTO setting. But that’s just a guess.
>>>
>>> Implementing read_description as you suggest should help. However,
>>> read_description should probably do HWCAP checking similar to the
>>> arm_linux_nat_target and arm_fbsd_nat_target versions.
>>>
>>> Without that, I’d worry that your patch below might start writing off the
>>> end of the regcache that had been allocated for a fewer number of registers.
>>
>> Hm... well, I've probably spent entirely too much time on this
>> already, but just in case there's an easy fix -- Kamil, does NetBSD
>> provide an API similar to Linux's HWCAP API that would let me check
>> which VFP version the current CPU is using? It seems AUXV does not
>> contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be
>> missing something.
>>
>> (Compare arm_fbsd_read_description_auxv /
>> arm_linux_nat_target::read_description)
>>
>> Christian
>>
> 
> Thank you for your work.
> 
> HWCAP in auxv is not supported (although there is a stub for it).
> 
> Here is a complete algorithm to detect FPU on ARM 32-bit.
> 
> http://netbsd.org/~kamil/arm-fpu.c
> 

Here is another example with SIMD:

http://cvsweb.netbsd.org/bsdweb.cgi/xsrc/external/mit/pixman/dist/pixman/pixman-arm.c.diff?r1=1.1&r2=1.2&f=h

>>>
>>>>>
>>>>> gdb/ChangeLog:
>>>>>
>>>>> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
>>>>>
>>>>>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
>>>>>        (arm_supply_vfpregset): ...this, and update to use VFP registers.
>>>>>        (fetch_fp_register): Update.
>>>>>        (fetch_fp_regs): Update.
>>>>>        (store_fp_register): Update.
>>>>>        (store_fp_regs): Update.
>>>>>        (fetch_elfcore_registers): Update.
>>>>> ---
>>>>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
>>>>> 1 file changed, 34 insertions(+), 46 deletions(-)
>>>>>
>>>>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
>>>>> index 11afc289c3..8027f54dfe 100644
>>>>> --- a/gdb/arm-nbsd-nat.c
>>>>> +++ b/gdb/arm-nbsd-nat.c
>>>>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
>>>>> }
>>>>>
>>>>> static void
>>>>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
>>>>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
>>>>> {
>>>>> -  int regno;
>>>>> -
>>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
>>>>> -    regcache->raw_supply (regno,
>>>>> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
>>>>> +  struct vfpreg &vfp = fpregset->fpr_vfp;
>>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>>>>> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>
>>>>> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
>>>>> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>>> }
>>>>>
>>>>> static void
>>>>> @@ -147,10 +145,10 @@ static void
>>>>> fetch_fp_register (struct regcache *regcache, int regno)
>>>>> {
>>>>>   struct fpreg inferior_fp_registers;
>>>>> -  int ret;
>>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>
>>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>>>>>
>>>>>   if (ret < 0)
>>>>>     {
>>>>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
>>>>>       return;
>>>>>     }
>>>>>
>>>>> -  switch (regno)
>>>>> +  if (regno == ARM_FPSCR_REGNUM)
>>>>> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>>>>>     {
>>>>> -    case ARM_FPS_REGNUM:
>>>>> -      regcache->raw_supply (ARM_FPS_REGNUM,
>>>>> -                           (char *) &inferior_fp_registers.fpr_fpsr);
>>>>> -      break;
>>>>> -
>>>>> -    default:
>>>>> -      regcache->raw_supply
>>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>>> -      break;
>>>>> +      regcache->raw_supply (regno,
>>>>> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>     }
>>>>> +  else
>>>>> +    warning (_("Invalid register number."));
>>>>> }
>>>>>
>>>>> static void
>>>>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
>>>>>       return;
>>>>>     }
>>>>>
>>>>> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
>>>>> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
>>>>> }
>>>>>
>>>>> void
>>>>> @@ -327,10 +322,9 @@ static void
>>>>> store_fp_register (const struct regcache *regcache, int regno)
>>>>> {
>>>>>   struct fpreg inferior_fp_registers;
>>>>> -  int ret;
>>>>> -
>>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>>>>>
>>>>>   if (ret < 0)
>>>>>     {
>>>>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
>>>>>       return;
>>>>>     }
>>>>>
>>>>> -  switch (regno)
>>>>> +  if (regno == ARM_FPSCR_REGNUM)
>>>>> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>>>>>     {
>>>>> -    case ARM_FPS_REGNUM:
>>>>> -      regcache->raw_collect (ARM_FPS_REGNUM,
>>>>> -                            (char *) &inferior_fp_registers.fpr_fpsr);
>>>>> -      break;
>>>>> -
>>>>> -    default:
>>>>> -      regcache->raw_collect
>>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>>> -      break;
>>>>> +      regcache->raw_collect (regno,
>>>>> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>     }
>>>>> +  else
>>>>> +    warning (_("Invalid register number."));
>>>>>
>>>>>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
>>>>> static void
>>>>> store_fp_regs (const struct regcache *regcache)
>>>>> {
>>>>> -  struct fpreg inferior_fp_registers;
>>>>> -  int ret;
>>>>> -  int regno;
>>>>> +  struct fpreg fpregs;
>>>>>
>>>>> -
>>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
>>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>>>>>     regcache->raw_collect
>>>>> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>>> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>
>>>>> -  regcache->raw_collect (ARM_FPS_REGNUM,
>>>>> -                        (char *) &inferior_fp_registers.fpr_fpsr);
>>>>> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
>>>>> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
>>>>>
>>>>> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
>>>>>
>>>>>   if (ret < 0)
>>>>>     warning (_("unable to store floating-point registers"));
>>>>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
>>>>>          /* The memcpy may be unnecessary, but we can't really be sure
>>>>>             of the alignment of the data in the core file.  */
>>>>>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
>>>>> -         arm_supply_fparegset (regcache, &fparegset);
>>>>> +         arm_supply_vfpregset (regcache, &fparegset);
>>>>>        }
>>>>>       break;
>>>>>
>>>>> --
>>>>> 2.25.0.225.g125e21ebc7-goog
>>>>>
>>>
> 
>
Doug Evans via gdb-patches - Feb. 12, 2020, 11:28 p.m.
Thanks, Kamil!

Please forgive the stupid question, but is SIMD in this context the
same as IWMMXT?

Christian

On Wed, Feb 12, 2020 at 11:16 AM Kamil Rytarowski <n54@gmx.com> wrote:
>
> On 12.02.2020 18:09, Kamil Rytarowski wrote:
> > On 12.02.2020 17:28, Christian Biesinger wrote:
> >> On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward <Alan.Hayward@arm.com> wrote:
> >>>
> >>>
> >>>
> >>>> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:
> >>>>
> >>>> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
> >>>> <cbiesinger@google.com> wrote:
> >>>>>
> >>>>> The floating point register interface has changed to this:
> >>>>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
> >>>>>
> >>>>> It now uses VFP instead of FPA registers. This patch updates
> >>>>> arm-nbsd-nat.c accordingly.
> >>>>>
> >>>>> Tested by compiling on arm-netbsd on qemu. For actually testing, there
> >>>>> seems to be something missing as "info registers" only shows FPA
> >>>>> registers and no VFP ones. I am still investigating why this is;
> >>>>> please let me know if you know. However, I think this is still good
> >>>>> to check in as-is.
> >>>>
> >>>> Hm... this is perhaps because arm_netbsd_nat_target does not implement
> >>>> read_description; if it returned arm_read_description
> >>>> (ARM_FP_TYPE_VFPV2) this may work?
> >>>>
> >>>
> >>> Yes, looks like netbsd isn’t using any target description functionality.
> >>>
> >>> I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
> >>> and then using the AUTO setting. But that’s just a guess.
> >>>
> >>> Implementing read_description as you suggest should help. However,
> >>> read_description should probably do HWCAP checking similar to the
> >>> arm_linux_nat_target and arm_fbsd_nat_target versions.
> >>>
> >>> Without that, I’d worry that your patch below might start writing off the
> >>> end of the regcache that had been allocated for a fewer number of registers.
> >>
> >> Hm... well, I've probably spent entirely too much time on this
> >> already, but just in case there's an easy fix -- Kamil, does NetBSD
> >> provide an API similar to Linux's HWCAP API that would let me check
> >> which VFP version the current CPU is using? It seems AUXV does not
> >> contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be
> >> missing something.
> >>
> >> (Compare arm_fbsd_read_description_auxv /
> >> arm_linux_nat_target::read_description)
> >>
> >> Christian
> >>
> >
> > Thank you for your work.
> >
> > HWCAP in auxv is not supported (although there is a stub for it).
> >
> > Here is a complete algorithm to detect FPU on ARM 32-bit.
> >
> > http://netbsd.org/~kamil/arm-fpu.c
> >
>
> Here is another example with SIMD:
>
> http://cvsweb.netbsd.org/bsdweb.cgi/xsrc/external/mit/pixman/dist/pixman/pixman-arm.c.diff?r1=1.1&r2=1.2&f=h
>
> >>>
> >>>>>
> >>>>> gdb/ChangeLog:
> >>>>>
> >>>>> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
> >>>>>
> >>>>>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
> >>>>>        (arm_supply_vfpregset): ...this, and update to use VFP registers.
> >>>>>        (fetch_fp_register): Update.
> >>>>>        (fetch_fp_regs): Update.
> >>>>>        (store_fp_register): Update.
> >>>>>        (store_fp_regs): Update.
> >>>>>        (fetch_elfcore_registers): Update.
> >>>>> ---
> >>>>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
> >>>>> 1 file changed, 34 insertions(+), 46 deletions(-)
> >>>>>
> >>>>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
> >>>>> index 11afc289c3..8027f54dfe 100644
> >>>>> --- a/gdb/arm-nbsd-nat.c
> >>>>> +++ b/gdb/arm-nbsd-nat.c
> >>>>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
> >>>>> }
> >>>>>
> >>>>> static void
> >>>>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
> >>>>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
> >>>>> {
> >>>>> -  int regno;
> >>>>> -
> >>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> >>>>> -    regcache->raw_supply (regno,
> >>>>> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
> >>>>> +  struct vfpreg &vfp = fpregset->fpr_vfp;
> >>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> >>>>> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>>>>
> >>>>> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
> >>>>> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> >>>>> }
> >>>>>
> >>>>> static void
> >>>>> @@ -147,10 +145,10 @@ static void
> >>>>> fetch_fp_register (struct regcache *regcache, int regno)
> >>>>> {
> >>>>>   struct fpreg inferior_fp_registers;
> >>>>> -  int ret;
> >>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>>>>
> >>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
> >>>>>
> >>>>>   if (ret < 0)
> >>>>>     {
> >>>>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
> >>>>>       return;
> >>>>>     }
> >>>>>
> >>>>> -  switch (regno)
> >>>>> +  if (regno == ARM_FPSCR_REGNUM)
> >>>>> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> >>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
> >>>>>     {
> >>>>> -    case ARM_FPS_REGNUM:
> >>>>> -      regcache->raw_supply (ARM_FPS_REGNUM,
> >>>>> -                           (char *) &inferior_fp_registers.fpr_fpsr);
> >>>>> -      break;
> >>>>> -
> >>>>> -    default:
> >>>>> -      regcache->raw_supply
> >>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> >>>>> -      break;
> >>>>> +      regcache->raw_supply (regno,
> >>>>> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>>>>     }
> >>>>> +  else
> >>>>> +    warning (_("Invalid register number."));
> >>>>> }
> >>>>>
> >>>>> static void
> >>>>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
> >>>>>       return;
> >>>>>     }
> >>>>>
> >>>>> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
> >>>>> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
> >>>>> }
> >>>>>
> >>>>> void
> >>>>> @@ -327,10 +322,9 @@ static void
> >>>>> store_fp_register (const struct regcache *regcache, int regno)
> >>>>> {
> >>>>>   struct fpreg inferior_fp_registers;
> >>>>> -  int ret;
> >>>>> -
> >>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> >>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
> >>>>>
> >>>>>   if (ret < 0)
> >>>>>     {
> >>>>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
> >>>>>       return;
> >>>>>     }
> >>>>>
> >>>>> -  switch (regno)
> >>>>> +  if (regno == ARM_FPSCR_REGNUM)
> >>>>> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> >>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
> >>>>>     {
> >>>>> -    case ARM_FPS_REGNUM:
> >>>>> -      regcache->raw_collect (ARM_FPS_REGNUM,
> >>>>> -                            (char *) &inferior_fp_registers.fpr_fpsr);
> >>>>> -      break;
> >>>>> -
> >>>>> -    default:
> >>>>> -      regcache->raw_collect
> >>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> >>>>> -      break;
> >>>>> +      regcache->raw_collect (regno,
> >>>>> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>>>>     }
> >>>>> +  else
> >>>>> +    warning (_("Invalid register number."));
> >>>>>
> >>>>>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> >>>>>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>>>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
> >>>>> static void
> >>>>> store_fp_regs (const struct regcache *regcache)
> >>>>> {
> >>>>> -  struct fpreg inferior_fp_registers;
> >>>>> -  int ret;
> >>>>> -  int regno;
> >>>>> +  struct fpreg fpregs;
> >>>>>
> >>>>> -
> >>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> >>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> >>>>>     regcache->raw_collect
> >>>>> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> >>>>> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> >>>>>
> >>>>> -  regcache->raw_collect (ARM_FPS_REGNUM,
> >>>>> -                        (char *) &inferior_fp_registers.fpr_fpsr);
> >>>>> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
> >>>>> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
> >>>>>
> >>>>> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> >>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> >>>>> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> >>>>> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
> >>>>>
> >>>>>   if (ret < 0)
> >>>>>     warning (_("unable to store floating-point registers"));
> >>>>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
> >>>>>          /* The memcpy may be unnecessary, but we can't really be sure
> >>>>>             of the alignment of the data in the core file.  */
> >>>>>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
> >>>>> -         arm_supply_fparegset (regcache, &fparegset);
> >>>>> +         arm_supply_vfpregset (regcache, &fparegset);
> >>>>>        }
> >>>>>       break;
> >>>>>
> >>>>> --
> >>>>> 2.25.0.225.g125e21ebc7-goog
> >>>>>
> >>>
> >
> >
>
>
Doug Evans via gdb-patches - Feb. 12, 2020, 11:42 p.m.
And one more question -- since VFP 1 is deprecated (not even mentioned
on http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0472j/chr1359124231926.html)
and your example codes don't include VFP 2, should I assume that
fpu_present implies VFP 3 and that VFPv3-D16 doesn't happen?

Thanks again,
Christian

On Wed, Feb 12, 2020 at 5:28 PM Christian Biesinger
<cbiesinger@google.com> wrote:
>
> Thanks, Kamil!
>
> Please forgive the stupid question, but is SIMD in this context the
> same as IWMMXT?
>
> Christian
>
> On Wed, Feb 12, 2020 at 11:16 AM Kamil Rytarowski <n54@gmx.com> wrote:
> >
> > On 12.02.2020 18:09, Kamil Rytarowski wrote:
> > > On 12.02.2020 17:28, Christian Biesinger wrote:
> > >> On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward <Alan.Hayward@arm.com> wrote:
> > >>>
> > >>>
> > >>>
> > >>>> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:
> > >>>>
> > >>>> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
> > >>>> <cbiesinger@google.com> wrote:
> > >>>>>
> > >>>>> The floating point register interface has changed to this:
> > >>>>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
> > >>>>>
> > >>>>> It now uses VFP instead of FPA registers. This patch updates
> > >>>>> arm-nbsd-nat.c accordingly.
> > >>>>>
> > >>>>> Tested by compiling on arm-netbsd on qemu. For actually testing, there
> > >>>>> seems to be something missing as "info registers" only shows FPA
> > >>>>> registers and no VFP ones. I am still investigating why this is;
> > >>>>> please let me know if you know. However, I think this is still good
> > >>>>> to check in as-is.
> > >>>>
> > >>>> Hm... this is perhaps because arm_netbsd_nat_target does not implement
> > >>>> read_description; if it returned arm_read_description
> > >>>> (ARM_FP_TYPE_VFPV2) this may work?
> > >>>>
> > >>>
> > >>> Yes, looks like netbsd isn’t using any target description functionality.
> > >>>
> > >>> I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
> > >>> and then using the AUTO setting. But that’s just a guess.
> > >>>
> > >>> Implementing read_description as you suggest should help. However,
> > >>> read_description should probably do HWCAP checking similar to the
> > >>> arm_linux_nat_target and arm_fbsd_nat_target versions.
> > >>>
> > >>> Without that, I’d worry that your patch below might start writing off the
> > >>> end of the regcache that had been allocated for a fewer number of registers.
> > >>
> > >> Hm... well, I've probably spent entirely too much time on this
> > >> already, but just in case there's an easy fix -- Kamil, does NetBSD
> > >> provide an API similar to Linux's HWCAP API that would let me check
> > >> which VFP version the current CPU is using? It seems AUXV does not
> > >> contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be
> > >> missing something.
> > >>
> > >> (Compare arm_fbsd_read_description_auxv /
> > >> arm_linux_nat_target::read_description)
> > >>
> > >> Christian
> > >>
> > >
> > > Thank you for your work.
> > >
> > > HWCAP in auxv is not supported (although there is a stub for it).
> > >
> > > Here is a complete algorithm to detect FPU on ARM 32-bit.
> > >
> > > http://netbsd.org/~kamil/arm-fpu.c
> > >
> >
> > Here is another example with SIMD:
> >
> > http://cvsweb.netbsd.org/bsdweb.cgi/xsrc/external/mit/pixman/dist/pixman/pixman-arm.c.diff?r1=1.1&r2=1.2&f=h
> >
> > >>>
> > >>>>>
> > >>>>> gdb/ChangeLog:
> > >>>>>
> > >>>>> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
> > >>>>>
> > >>>>>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
> > >>>>>        (arm_supply_vfpregset): ...this, and update to use VFP registers.
> > >>>>>        (fetch_fp_register): Update.
> > >>>>>        (fetch_fp_regs): Update.
> > >>>>>        (store_fp_register): Update.
> > >>>>>        (store_fp_regs): Update.
> > >>>>>        (fetch_elfcore_registers): Update.
> > >>>>> ---
> > >>>>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
> > >>>>> 1 file changed, 34 insertions(+), 46 deletions(-)
> > >>>>>
> > >>>>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
> > >>>>> index 11afc289c3..8027f54dfe 100644
> > >>>>> --- a/gdb/arm-nbsd-nat.c
> > >>>>> +++ b/gdb/arm-nbsd-nat.c
> > >>>>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
> > >>>>> }
> > >>>>>
> > >>>>> static void
> > >>>>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
> > >>>>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
> > >>>>> {
> > >>>>> -  int regno;
> > >>>>> -
> > >>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> > >>>>> -    regcache->raw_supply (regno,
> > >>>>> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
> > >>>>> +  struct vfpreg &vfp = fpregset->fpr_vfp;
> > >>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> > >>>>> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> > >>>>>
> > >>>>> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
> > >>>>> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> > >>>>> }
> > >>>>>
> > >>>>> static void
> > >>>>> @@ -147,10 +145,10 @@ static void
> > >>>>> fetch_fp_register (struct regcache *regcache, int regno)
> > >>>>> {
> > >>>>>   struct fpreg inferior_fp_registers;
> > >>>>> -  int ret;
> > >>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> > >>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> > >>>>>
> > >>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> > >>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> > >>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
> > >>>>>
> > >>>>>   if (ret < 0)
> > >>>>>     {
> > >>>>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
> > >>>>>       return;
> > >>>>>     }
> > >>>>>
> > >>>>> -  switch (regno)
> > >>>>> +  if (regno == ARM_FPSCR_REGNUM)
> > >>>>> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> > >>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
> > >>>>>     {
> > >>>>> -    case ARM_FPS_REGNUM:
> > >>>>> -      regcache->raw_supply (ARM_FPS_REGNUM,
> > >>>>> -                           (char *) &inferior_fp_registers.fpr_fpsr);
> > >>>>> -      break;
> > >>>>> -
> > >>>>> -    default:
> > >>>>> -      regcache->raw_supply
> > >>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> > >>>>> -      break;
> > >>>>> +      regcache->raw_supply (regno,
> > >>>>> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> > >>>>>     }
> > >>>>> +  else
> > >>>>> +    warning (_("Invalid register number."));
> > >>>>> }
> > >>>>>
> > >>>>> static void
> > >>>>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
> > >>>>>       return;
> > >>>>>     }
> > >>>>>
> > >>>>> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
> > >>>>> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
> > >>>>> }
> > >>>>>
> > >>>>> void
> > >>>>> @@ -327,10 +322,9 @@ static void
> > >>>>> store_fp_register (const struct regcache *regcache, int regno)
> > >>>>> {
> > >>>>>   struct fpreg inferior_fp_registers;
> > >>>>> -  int ret;
> > >>>>> -
> > >>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> > >>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> > >>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
> > >>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> > >>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
> > >>>>>
> > >>>>>   if (ret < 0)
> > >>>>>     {
> > >>>>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
> > >>>>>       return;
> > >>>>>     }
> > >>>>>
> > >>>>> -  switch (regno)
> > >>>>> +  if (regno == ARM_FPSCR_REGNUM)
> > >>>>> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
> > >>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
> > >>>>>     {
> > >>>>> -    case ARM_FPS_REGNUM:
> > >>>>> -      regcache->raw_collect (ARM_FPS_REGNUM,
> > >>>>> -                            (char *) &inferior_fp_registers.fpr_fpsr);
> > >>>>> -      break;
> > >>>>> -
> > >>>>> -    default:
> > >>>>> -      regcache->raw_collect
> > >>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> > >>>>> -      break;
> > >>>>> +      regcache->raw_collect (regno,
> > >>>>> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> > >>>>>     }
> > >>>>> +  else
> > >>>>> +    warning (_("Invalid register number."));
> > >>>>>
> > >>>>>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> > >>>>>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> > >>>>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
> > >>>>> static void
> > >>>>> store_fp_regs (const struct regcache *regcache)
> > >>>>> {
> > >>>>> -  struct fpreg inferior_fp_registers;
> > >>>>> -  int ret;
> > >>>>> -  int regno;
> > >>>>> +  struct fpreg fpregs;
> > >>>>>
> > >>>>> -
> > >>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
> > >>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
> > >>>>>     regcache->raw_collect
> > >>>>> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
> > >>>>> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
> > >>>>>
> > >>>>> -  regcache->raw_collect (ARM_FPS_REGNUM,
> > >>>>> -                        (char *) &inferior_fp_registers.fpr_fpsr);
> > >>>>> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
> > >>>>> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
> > >>>>>
> > >>>>> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> > >>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
> > >>>>> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
> > >>>>> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
> > >>>>>
> > >>>>>   if (ret < 0)
> > >>>>>     warning (_("unable to store floating-point registers"));
> > >>>>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
> > >>>>>          /* The memcpy may be unnecessary, but we can't really be sure
> > >>>>>             of the alignment of the data in the core file.  */
> > >>>>>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
> > >>>>> -         arm_supply_fparegset (regcache, &fparegset);
> > >>>>> +         arm_supply_vfpregset (regcache, &fparegset);
> > >>>>>        }
> > >>>>>       break;
> > >>>>>
> > >>>>> --
> > >>>>> 2.25.0.225.g125e21ebc7-goog
> > >>>>>
> > >>>
> > >
> > >
> >
> >
Kamil Rytarowski - Feb. 13, 2020, midnight
On 13.02.2020 00:42, Christian Biesinger via gdb-patches wrote:
> And one more question -- since VFP 1 is deprecated (not even mentioned
> on http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0472j/chr1359124231926.html)
> and your example codes don't include VFP 2, should I assume that
> fpu_present implies VFP 3 and that VFPv3-D16 doesn't happen?
> 

In theory we support what was mentioned in
http://netbsd.org/~kamil/arm-fpu.c

The kernel VFP attach function is located here:
https://nxr.netbsd.org/xref/src/sys/arch/arm/vfp/vfp_init.c#250

Today it is safe to assume VFPv3. As far as I am aware, VFPv3-D16 is
unsupported.

> Thanks again,
> Christian
> 
> On Wed, Feb 12, 2020 at 5:28 PM Christian Biesinger
> <cbiesinger@google.com> wrote:
>>
>> Thanks, Kamil!
>>
>> Please forgive the stupid question, but is SIMD in this context the
>> same as IWMMXT?
>>

iwmmxt is unsupported.

>> Christian
>>
>> On Wed, Feb 12, 2020 at 11:16 AM Kamil Rytarowski <n54@gmx.com> wrote:
>>>
>>> On 12.02.2020 18:09, Kamil Rytarowski wrote:
>>>> On 12.02.2020 17:28, Christian Biesinger wrote:
>>>>> On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward <Alan.Hayward@arm.com> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> wrote:
>>>>>>>
>>>>>>> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger
>>>>>>> <cbiesinger@google.com> wrote:
>>>>>>>>
>>>>>>>> The floating point register interface has changed to this:
>>>>>>>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
>>>>>>>>
>>>>>>>> It now uses VFP instead of FPA registers. This patch updates
>>>>>>>> arm-nbsd-nat.c accordingly.
>>>>>>>>
>>>>>>>> Tested by compiling on arm-netbsd on qemu. For actually testing, there
>>>>>>>> seems to be something missing as "info registers" only shows FPA
>>>>>>>> registers and no VFP ones. I am still investigating why this is;
>>>>>>>> please let me know if you know. However, I think this is still good
>>>>>>>> to check in as-is.
>>>>>>>
>>>>>>> Hm... this is perhaps because arm_netbsd_nat_target does not implement
>>>>>>> read_description; if it returned arm_read_description
>>>>>>> (ARM_FP_TYPE_VFPV2) this may work?
>>>>>>>
>>>>>>
>>>>>> Yes, looks like netbsd isn’t using any target description functionality.
>>>>>>
>>>>>> I suspect the code is getting into arm_gdbarch_init() with a null tdesc,
>>>>>> and then using the AUTO setting. But that’s just a guess.
>>>>>>
>>>>>> Implementing read_description as you suggest should help. However,
>>>>>> read_description should probably do HWCAP checking similar to the
>>>>>> arm_linux_nat_target and arm_fbsd_nat_target versions.
>>>>>>
>>>>>> Without that, I’d worry that your patch below might start writing off the
>>>>>> end of the regcache that had been allocated for a fewer number of registers.
>>>>>
>>>>> Hm... well, I've probably spent entirely too much time on this
>>>>> already, but just in case there's an easy fix -- Kamil, does NetBSD
>>>>> provide an API similar to Linux's HWCAP API that would let me check
>>>>> which VFP version the current CPU is using? It seems AUXV does not
>>>>> contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be
>>>>> missing something.
>>>>>
>>>>> (Compare arm_fbsd_read_description_auxv /
>>>>> arm_linux_nat_target::read_description)
>>>>>
>>>>> Christian
>>>>>
>>>>
>>>> Thank you for your work.
>>>>
>>>> HWCAP in auxv is not supported (although there is a stub for it).
>>>>
>>>> Here is a complete algorithm to detect FPU on ARM 32-bit.
>>>>
>>>> http://netbsd.org/~kamil/arm-fpu.c
>>>>
>>>
>>> Here is another example with SIMD:
>>>
>>> http://cvsweb.netbsd.org/bsdweb.cgi/xsrc/external/mit/pixman/dist/pixman/pixman-arm.c.diff?r1=1.1&r2=1.2&f=h
>>>
>>>>>>
>>>>>>>>
>>>>>>>> gdb/ChangeLog:
>>>>>>>>
>>>>>>>> 2020-02-11  Christian Biesinger  <cbiesinger@google.com>
>>>>>>>>
>>>>>>>>        * arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
>>>>>>>>        (arm_supply_vfpregset): ...this, and update to use VFP registers.
>>>>>>>>        (fetch_fp_register): Update.
>>>>>>>>        (fetch_fp_regs): Update.
>>>>>>>>        (store_fp_register): Update.
>>>>>>>>        (store_fp_regs): Update.
>>>>>>>>        (fetch_elfcore_registers): Update.
>>>>>>>> ---
>>>>>>>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++--------------------------
>>>>>>>> 1 file changed, 34 insertions(+), 46 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
>>>>>>>> index 11afc289c3..8027f54dfe 100644
>>>>>>>> --- a/gdb/arm-nbsd-nat.c
>>>>>>>> +++ b/gdb/arm-nbsd-nat.c
>>>>>>>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
>>>>>>>> }
>>>>>>>>
>>>>>>>> static void
>>>>>>>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
>>>>>>>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
>>>>>>>> {
>>>>>>>> -  int regno;
>>>>>>>> -
>>>>>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
>>>>>>>> -    regcache->raw_supply (regno,
>>>>>>>> -                         (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
>>>>>>>> +  struct vfpreg &vfp = fpregset->fpr_vfp;
>>>>>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>>>>>>>> +    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>>>>
>>>>>>>> -  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
>>>>>>>> +  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>>>>>> }
>>>>>>>>
>>>>>>>> static void
>>>>>>>> @@ -147,10 +145,10 @@ static void
>>>>>>>> fetch_fp_register (struct regcache *regcache, int regno)
>>>>>>>> {
>>>>>>>>   struct fpreg inferior_fp_registers;
>>>>>>>> -  int ret;
>>>>>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>>>>
>>>>>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>>>>>>>>
>>>>>>>>   if (ret < 0)
>>>>>>>>     {
>>>>>>>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno)
>>>>>>>>       return;
>>>>>>>>     }
>>>>>>>>
>>>>>>>> -  switch (regno)
>>>>>>>> +  if (regno == ARM_FPSCR_REGNUM)
>>>>>>>> +    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>>>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>>>>>>>>     {
>>>>>>>> -    case ARM_FPS_REGNUM:
>>>>>>>> -      regcache->raw_supply (ARM_FPS_REGNUM,
>>>>>>>> -                           (char *) &inferior_fp_registers.fpr_fpsr);
>>>>>>>> -      break;
>>>>>>>> -
>>>>>>>> -    default:
>>>>>>>> -      regcache->raw_supply
>>>>>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>>>>>> -      break;
>>>>>>>> +      regcache->raw_supply (regno,
>>>>>>>> +                           (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>>>>     }
>>>>>>>> +  else
>>>>>>>> +    warning (_("Invalid register number."));
>>>>>>>> }
>>>>>>>>
>>>>>>>> static void
>>>>>>>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache)
>>>>>>>>       return;
>>>>>>>>     }
>>>>>>>>
>>>>>>>> -  arm_supply_fparegset (regcache, &inferior_fp_registers);
>>>>>>>> +  arm_supply_vfpregset (regcache, &inferior_fp_registers);
>>>>>>>> }
>>>>>>>>
>>>>>>>> void
>>>>>>>> @@ -327,10 +322,9 @@ static void
>>>>>>>> store_fp_register (const struct regcache *regcache, int regno)
>>>>>>>> {
>>>>>>>>   struct fpreg inferior_fp_registers;
>>>>>>>> -  int ret;
>>>>>>>> -
>>>>>>>> -  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>>>> +  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
>>>>>>>> +                   (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>>>> +  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
>>>>>>>>
>>>>>>>>   if (ret < 0)
>>>>>>>>     {
>>>>>>>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno)
>>>>>>>>       return;
>>>>>>>>     }
>>>>>>>>
>>>>>>>> -  switch (regno)
>>>>>>>> +  if (regno == ARM_FPSCR_REGNUM)
>>>>>>>> +    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
>>>>>>>> +  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
>>>>>>>>     {
>>>>>>>> -    case ARM_FPS_REGNUM:
>>>>>>>> -      regcache->raw_collect (ARM_FPS_REGNUM,
>>>>>>>> -                            (char *) &inferior_fp_registers.fpr_fpsr);
>>>>>>>> -      break;
>>>>>>>> -
>>>>>>>> -    default:
>>>>>>>> -      regcache->raw_collect
>>>>>>>> -       (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>>>>>> -      break;
>>>>>>>> +      regcache->raw_collect (regno,
>>>>>>>> +                            (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>>>>     }
>>>>>>>> +  else
>>>>>>>> +    warning (_("Invalid register number."));
>>>>>>>>
>>>>>>>>   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>>>>>                (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>>>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno)
>>>>>>>> static void
>>>>>>>> store_fp_regs (const struct regcache *regcache)
>>>>>>>> {
>>>>>>>> -  struct fpreg inferior_fp_registers;
>>>>>>>> -  int ret;
>>>>>>>> -  int regno;
>>>>>>>> +  struct fpreg fpregs;
>>>>>>>>
>>>>>>>> -
>>>>>>>> -  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
>>>>>>>> +  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
>>>>>>>>     regcache->raw_collect
>>>>>>>> -      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
>>>>>>>> +      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
>>>>>>>>
>>>>>>>> -  regcache->raw_collect (ARM_FPS_REGNUM,
>>>>>>>> -                        (char *) &inferior_fp_registers.fpr_fpsr);
>>>>>>>> +  regcache->raw_collect (ARM_FPSCR_REGNUM,
>>>>>>>> +                        (char *) &fpregs.fpr_vfp.vfp_fpscr);
>>>>>>>>
>>>>>>>> -  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>>>>> -               (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
>>>>>>>> +  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
>>>>>>>> +                   (PTRACE_TYPE_ARG3) &fpregs, 0);
>>>>>>>>
>>>>>>>>   if (ret < 0)
>>>>>>>>     warning (_("unable to store floating-point registers"));
>>>>>>>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache,
>>>>>>>>          /* The memcpy may be unnecessary, but we can't really be sure
>>>>>>>>             of the alignment of the data in the core file.  */
>>>>>>>>          memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
>>>>>>>> -         arm_supply_fparegset (regcache, &fparegset);
>>>>>>>> +         arm_supply_vfpregset (regcache, &fparegset);
>>>>>>>>        }
>>>>>>>>       break;
>>>>>>>>
>>>>>>>> --
>>>>>>>> 2.25.0.225.g125e21ebc7-goog
>>>>>>>>
>>>>>>
>>>>
>>>>
>>>
>>>

Patch

diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c
index 11afc289c3..8027f54dfe 100644
--- a/gdb/arm-nbsd-nat.c
+++ b/gdb/arm-nbsd-nat.c
@@ -65,15 +65,13 @@  arm_supply_gregset (struct regcache *regcache, struct reg *gregset)
 }
 
 static void
-arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset)
+arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset)
 {
-  int regno;
-
-  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
-    regcache->raw_supply (regno,
-			  (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]);
+  struct vfpreg &vfp = fpregset->fpr_vfp;
+  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
+    regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
 
-  regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr);
+  regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
 }
 
 static void
@@ -147,10 +145,10 @@  static void
 fetch_fp_register (struct regcache *regcache, int regno)
 {
   struct fpreg inferior_fp_registers;
-  int ret;
+  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
+		    (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
 
-  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
-		(PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
+  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
 
   if (ret < 0)
     {
@@ -158,18 +156,15 @@  fetch_fp_register (struct regcache *regcache, int regno)
       return;
     }
 
-  switch (regno)
+  if (regno == ARM_FPSCR_REGNUM)
+    regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
+  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
     {
-    case ARM_FPS_REGNUM:
-      regcache->raw_supply (ARM_FPS_REGNUM,
-			    (char *) &inferior_fp_registers.fpr_fpsr);
-      break;
-
-    default:
-      regcache->raw_supply
-	(regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
-      break;
+      regcache->raw_supply (regno,
+			    (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
     }
+  else
+    warning (_("Invalid register number."));
 }
 
 static void
@@ -188,7 +183,7 @@  fetch_fp_regs (struct regcache *regcache)
       return;
     }
 
-  arm_supply_fparegset (regcache, &inferior_fp_registers);
+  arm_supply_vfpregset (regcache, &inferior_fp_registers);
 }
 
 void
@@ -327,10 +322,9 @@  static void
 store_fp_register (const struct regcache *regcache, int regno)
 {
   struct fpreg inferior_fp_registers;
-  int ret;
-
-  ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
-		(PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
+  int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (),
+		    (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
+  struct vfpreg &vfp = inferior_fp_registers.fpr_vfp;
 
   if (ret < 0)
     {
@@ -338,18 +332,15 @@  store_fp_register (const struct regcache *regcache, int regno)
       return;
     }
 
-  switch (regno)
+  if (regno == ARM_FPSCR_REGNUM)
+    regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr);
+  else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM)
     {
-    case ARM_FPS_REGNUM:
-      regcache->raw_collect (ARM_FPS_REGNUM,
-			     (char *) &inferior_fp_registers.fpr_fpsr);
-      break;
-
-    default:
-      regcache->raw_collect
-	(regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
-      break;
+      regcache->raw_collect (regno,
+			     (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]);
     }
+  else
+    warning (_("Invalid register number."));
 
   ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
 		(PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
@@ -361,20 +352,17 @@  store_fp_register (const struct regcache *regcache, int regno)
 static void
 store_fp_regs (const struct regcache *regcache)
 {
-  struct fpreg inferior_fp_registers;
-  int ret;
-  int regno;
+  struct fpreg fpregs;
 
-
-  for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
+  for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++)
     regcache->raw_collect
-      (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]);
+      (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]);
 
-  regcache->raw_collect (ARM_FPS_REGNUM,
-			 (char *) &inferior_fp_registers.fpr_fpsr);
+  regcache->raw_collect (ARM_FPSCR_REGNUM,
+			 (char *) &fpregs.fpr_vfp.vfp_fpscr);
 
-  ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
-		(PTRACE_TYPE_ARG3) &inferior_fp_registers, 0);
+  int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (),
+		    (PTRACE_TYPE_ARG3) &fpregs, 0);
 
   if (ret < 0)
     warning (_("unable to store floating-point registers"));
@@ -427,7 +415,7 @@  fetch_elfcore_registers (struct regcache *regcache,
 	  /* The memcpy may be unnecessary, but we can't really be sure
 	     of the alignment of the data in the core file.  */
 	  memcpy (&fparegset, core_reg_sect, sizeof (fparegset));
-	  arm_supply_fparegset (regcache, &fparegset);
+	  arm_supply_vfpregset (regcache, &fparegset);
 	}
       break;