From: Yao Qi <qiyaoltc@gmail.com>
To: Alan Hayward <Alan.Hayward@arm.com>
Cc: "gdb-patches\@sourceware.org" <gdb-patches@sourceware.org>,
nd <nd@arm.com>
Subject: Re: [PATCH] Simplify regcache_cpy and remove regcache::cpy_no_passthrough
Date: Mon, 17 Jul 2017 11:32:00 -0000 [thread overview]
Message-ID: <86k237s3hl.fsf@gmail.com> (raw)
In-Reply-To: <CCE54772-81EB-4A70-A990-ACE3BF29A767@arm.com> (Alan Hayward's message of "Mon, 17 Jul 2017 09:04:22 +0000")
Alan Hayward <Alan.Hayward@arm.com> writes:
> If not, then there should be a comment above regcache_cpy stating the
> restrictions.
I updated the comments to regcache_dup and regcache_cpy.
--
Yao (齐尧)
From 4ff91e90cad73f9420f8ca37fc7e22f465ebcb88 Mon Sep 17 00:00:00 2001
From: Yao Qi <yao.qi@linaro.org>
Date: Mon, 19 Jun 2017 22:45:12 +0100
Subject: [PATCH] Simplify regcache_cpy and remove regcache::cpy_no_passthrough
Nowadays, regcache_cpy is used where src is read-only and dst is not
read-only, so the regcache_cpy can be simplified to handle this case only.
As a result, regcache::cpy_no_passthrough, which is about two read-only
regcache copy, is no longer used, remove it as well.
gdb:
2017-07-17 Yao Qi <yao.qi@linaro.org>
* regcache.c (regcache_cpy): Simplify it.
(regcache::cpy_no_passthrough): Remove it.
* regcache.h (cpy_no_passthrough): Remove it.
(regcache_dup, regcache_cpy): Update comments.
diff --git a/gdb/regcache.c b/gdb/regcache.c
index 7eeb737..e8f92d6 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -388,36 +388,9 @@ regcache_cpy (struct regcache *dst, struct regcache *src)
gdb_assert (src != NULL && dst != NULL);
gdb_assert (src->m_descr->gdbarch == dst->m_descr->gdbarch);
gdb_assert (src != dst);
- gdb_assert (src->m_readonly_p || dst->m_readonly_p);
+ gdb_assert (src->m_readonly_p && !dst->m_readonly_p);
- if (!src->m_readonly_p)
- regcache_save (dst, do_cooked_read, src);
- else if (!dst->m_readonly_p)
- dst->restore (src);
- else
- dst->cpy_no_passthrough (src);
-}
-
-/* Copy/duplicate the contents of a register cache. Unlike regcache_cpy,
- which is pass-through, this does not go through to the target.
- Only values values already in the cache are transferred. The SRC and DST
- buffers must not overlap. */
-
-void
-regcache::cpy_no_passthrough (struct regcache *src)
-{
- gdb_assert (src != NULL);
- gdb_assert (src->m_descr->gdbarch == m_descr->gdbarch);
- /* NOTE: cagney/2002-05-17: Don't let the caller do a no-passthrough
- move of data into a thread's regcache. Doing this would be silly
- - it would mean that regcache->register_status would be
- completely invalid. */
- gdb_assert (m_readonly_p && src->m_readonly_p);
-
- memcpy (m_registers, src->m_registers,
- m_descr->sizeof_cooked_registers);
- memcpy (m_register_status, src->m_register_status,
- m_descr->sizeof_cooked_register_status);
+ dst->restore (src);
}
struct regcache *
diff --git a/gdb/regcache.h b/gdb/regcache.h
index b416d5e..aa64a00 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -369,8 +369,6 @@ private:
void restore (struct regcache *src);
- void cpy_no_passthrough (struct regcache *src);
-
enum register_status xfer_part (int regnum, int offset, int len, void *in,
const void *out,
decltype (regcache_raw_read) read,
@@ -415,13 +413,12 @@ private:
regcache_cpy (struct regcache *dst, struct regcache *src);
};
-/* Copy/duplicate the contents of a register cache. By default, the
- operation is pass-through. Writes to DST and reads from SRC will
- go through to the target. See also regcache_cpy_no_passthrough.
-
- regcache_cpy can not have overlapping SRC and DST buffers. */
-
+/* Duplicate the contents of a register cache to a read-only register
+ cache. The operation is pass-through. */
extern struct regcache *regcache_dup (struct regcache *regcache);
+
+/* Writes to DEST will go through to the target. SRC is a read-only
+ register cache. */
extern void regcache_cpy (struct regcache *dest, struct regcache *src);
extern void registers_changed (void);
next prev parent reply other threads:[~2017-07-17 11:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-27 7:37 Yao Qi
2017-07-17 9:04 ` Alan Hayward
2017-07-17 11:32 ` Yao Qi [this message]
2017-07-18 9:01 ` Alan Hayward
2017-07-18 11:49 ` Yao Qi
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