Remove MAX_REGISTER_SIZE from regcache.c
Commit Message
Alan Hayward <Alan.Hayward@arm.com> writes:
>>> @@ -395,9 +404,9 @@ regcache_restore (struct regcache *dst,
>>> {
>>> enum register_status status;
>>
>> Can we move "buf" here? and initialize it with the register_size,
>>
>> std::vector<gdb_byte> buf (register_size (gdbarch, regnum));
>>
>> then, we don't need max_register_size ().
>>
>
> Problem with this is that we are then creating a brand new buffer for each
> iteration of the loop, which is a little heavyweight.
> We could create an empty buf outside the loop and re-size it each iteration,
> but that's still going to cost.
>
How is this patch below? I class-fied regcache last month in my local
tree, and MAX_REGISTER_SIZE is disappeared from regcache.c. I suggested
using std::vector in a loop so that it is easy to rebase my patches.
Comments
> On 10 Apr 2017, at 09:59, Yao Qi <qiyaoltc@gmail.com> wrote:
>
> Alan Hayward <Alan.Hayward@arm.com> writes:
>
>>>> @@ -395,9 +404,9 @@ regcache_restore (struct regcache *dst,
>>>> {
>>>> enum register_status status;
>>>
>>> Can we move "buf" here? and initialize it with the register_size,
>>>
>>> std::vector<gdb_byte> buf (register_size (gdbarch, regnum));
>>>
>>> then, we don't need max_register_size ().
>>>
>>
>> Problem with this is that we are then creating a brand new buffer for each
>> iteration of the loop, which is a little heavyweight.
>> We could create an empty buf outside the loop and re-size it each iteration,
>> but that's still going to cost.
>>
>
> How is this patch below? I class-fied regcache last month in my local
> tree, and MAX_REGISTER_SIZE is disappeared from regcache.c. I suggested
> using std::vector in a loop so that it is easy to rebase my patches.
>
I’m happy with this. It also simplifies the code logic a little, which is good.
This would then reduce my patch to recache_save and regcache_dump changes.
Alan.
> --
> Yao (齐尧)
> From 25d562b5f858314ad9d41a7ffa825d8d24e3828e Mon Sep 17 00:00:00 2001
> From: Yao Qi <yao.qi@linaro.org>
> Date: Fri, 7 Apr 2017 22:50:27 +0100
> Subject: [PATCH] Simplify regcache_restore
>
> This patches removes the 2nd argument of regcache_restore, because it
> is only called by regcache_cpy. In regcache_cpy, if regcache_restore
> is called, dst is not readonly, but src is readonly. So this patch
> adds an assert that src is readonly in regcache_restore.
> regcache_cook_read read everything from a readonly regcache cache
> (src)'s register_buffer, and register status is from src->register_status.
>
> gdb:
>
> 2017-04-07 Yao Qi <yao.qi@linaro.org>
>
> * regcache.c (regcache_restore): Remove argument 2. Replace
> argument 3 with regcache. Get register status from
> src->register_status and get register contents from
> register_buffer (src, regnum).
> (regcache_cpy): Update.
>
> diff --git a/gdb/regcache.c b/gdb/regcache.c
> index 37bc2f0..41c23a5 100644
> --- a/gdb/regcache.c
> +++ b/gdb/regcache.c
> @@ -374,17 +374,15 @@ regcache_save (struct regcache *dst, regcache_cooked_read_ftype *cooked_read,
> }
>
> static void
> -regcache_restore (struct regcache *dst,
> - regcache_cooked_read_ftype *cooked_read,
> - void *cooked_read_context)
> +regcache_restore (struct regcache *dst, struct regcache *src)
> {
> struct gdbarch *gdbarch = dst->descr->gdbarch;
> - gdb_byte buf[MAX_REGISTER_SIZE];
> int regnum;
>
> /* The dst had better not be read-only. If it is, the `restore'
> doesn't make much sense. */
> gdb_assert (!dst->readonly_p);
> + gdb_assert (src->readonly_p);
> /* Copy over any registers, being careful to only restore those that
> were both saved and need to be restored. The full [0 .. gdbarch_num_regs
> + gdbarch_num_pseudo_regs) range is checked since some architectures need
> @@ -393,11 +391,8 @@ regcache_restore (struct regcache *dst,
> {
> if (gdbarch_register_reggroup_p (gdbarch, regnum, restore_reggroup))
> {
> - enum register_status status;
> -
> - status = cooked_read (cooked_read_context, regnum, buf);
> - if (status == REG_VALID)
> - regcache_cooked_write (dst, regnum, buf);
> + if (src->register_status[regnum] == REG_VALID)
> + regcache_cooked_write (dst, regnum, register_buffer (src, regnum));
> }
> }
> }
> @@ -424,7 +419,7 @@ regcache_cpy (struct regcache *dst, struct regcache *src)
> if (!src->readonly_p)
> regcache_save (dst, do_cooked_read, src);
> else if (!dst->readonly_p)
> - regcache_restore (dst, do_cooked_read, src);
> + regcache_restore (dst, src);
> else
> regcache_cpy_no_passthrough (dst, src);
> }
On Mon, Apr 10, 2017 at 9:59 AM, Yao Qi <qiyaoltc@gmail.com> wrote:
>
> This patches removes the 2nd argument of regcache_restore, because it
> is only called by regcache_cpy. In regcache_cpy, if regcache_restore
> is called, dst is not readonly, but src is readonly. So this patch
> adds an assert that src is readonly in regcache_restore.
> regcache_cook_read read everything from a readonly regcache cache
> (src)'s register_buffer, and register status is from src->register_status.
>
> gdb:
>
> 2017-04-07 Yao Qi <yao.qi@linaro.org>
>
> * regcache.c (regcache_restore): Remove argument 2. Replace
> argument 3 with regcache. Get register status from
> src->register_status and get register contents from
> register_buffer (src, regnum).
> (regcache_cpy): Update.
>
Tested it again on x86_64-linux. Pushed it in.
@@ -374,17 +374,15 @@ regcache_save (struct regcache *dst, regcache_cooked_read_ftype *cooked_read,
}
static void
-regcache_restore (struct regcache *dst,
- regcache_cooked_read_ftype *cooked_read,
- void *cooked_read_context)
+regcache_restore (struct regcache *dst, struct regcache *src)
{
struct gdbarch *gdbarch = dst->descr->gdbarch;
- gdb_byte buf[MAX_REGISTER_SIZE];
int regnum;
/* The dst had better not be read-only. If it is, the `restore'
doesn't make much sense. */
gdb_assert (!dst->readonly_p);
+ gdb_assert (src->readonly_p);
/* Copy over any registers, being careful to only restore those that
were both saved and need to be restored. The full [0 .. gdbarch_num_regs
+ gdbarch_num_pseudo_regs) range is checked since some architectures need
@@ -393,11 +391,8 @@ regcache_restore (struct regcache *dst,
{
if (gdbarch_register_reggroup_p (gdbarch, regnum, restore_reggroup))
{
- enum register_status status;
-
- status = cooked_read (cooked_read_context, regnum, buf);
- if (status == REG_VALID)
- regcache_cooked_write (dst, regnum, buf);
+ if (src->register_status[regnum] == REG_VALID)
+ regcache_cooked_write (dst, regnum, register_buffer (src, regnum));
}
}
}
@@ -424,7 +419,7 @@ regcache_cpy (struct regcache *dst, struct regcache *src)
if (!src->readonly_p)
regcache_save (dst, do_cooked_read, src);
else if (!dst->readonly_p)
- regcache_restore (dst, do_cooked_read, src);
+ regcache_restore (dst, src);
else
regcache_cpy_no_passthrough (dst, src);
}