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Re: [PATCH v2] gdb/hppa-tdep.c: Fix logical working flow typo issue
- From: Chen Gang <gang dot chen dot 5i5j at gmail dot com>
- To: gdb-patches at sourceware dot org
- Cc: Andreas Schwab <schwab at suse dot de>, Joel Brobecker <brobecker at adacore dot com>
- Date: Sat, 25 Oct 2014 06:47:48 +0800
- Subject: Re: [PATCH v2] gdb/hppa-tdep.c: Fix logical working flow typo issue
- Authentication-results: sourceware.org; auth=none
- References: <5447CF8A dot 6020603 at gmail dot com>
Hello all:
Is this patch OK, it is part of checking saving registers in the stack,
it tries to recognize the saving instructions "stb, stw(m), or std", so
can continue checking.
Excuse me, I have no related environments for a test, I assumed that the
original author knew about the working flow, then wrote the related
function.
If need additional analyzing, please let me know (better to let me know
what I need try, next).
Thanks.
On 10/22/14 23:38, Chen Gang wrote:
> inst_saves_gr() wants to recognize 'st??' instruction, according to the
> code we know it include 'stb' (for store byte), 'stw(m)' (for store
> word), and 'std' (for store double word).
>
> They should be in the same format, and have neighbour numbers:
> especially, 'stw(m)' need be in the middle of 'stb' and 'std'.
>
> - for ((inst >> 26) != 0x3):
>
> stb: 0x18, or 0x19,
> stw: 0x1a, stwm: 0x1b,
> std: 0x1c.
>
> - else ((inst >> 26) == 0x3), need check:
>
> stb: 0x08, or 0x09,
> stw: 0x0a,
> std: 0x0b.
>
> For clearer reason, not combine the logical comparation code together.
>
> 2014-10-22 Chen Gang <gang.chen.5i5j@gmail.com>
>
> * hppa-tdep.c (inst_saves_gr): Fix logical working flow typo
> issue.
>
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
> ---
> gdb/hppa-tdep.c | 33 ++++++++++++++++++++++++---------
> 1 file changed, 24 insertions(+), 9 deletions(-)
>
> diff --git a/gdb/hppa-tdep.c b/gdb/hppa-tdep.c
> index 627f31a..4363ab4 100644
> --- a/gdb/hppa-tdep.c
> +++ b/gdb/hppa-tdep.c
> @@ -1376,16 +1376,35 @@ is_branch (unsigned long inst)
> }
>
> /* Return the register number for a GR which is saved by INST or
> - zero it INST does not save a GR. */
> + zero it INST does not save a GR.
> +
> + inst_saves_gr() wants to recognize 'st??' instruction, it include 'stb' (for
> + store byte), 'stw(m)' (for store word), and 'std' (for store double word).
> +
> + They should be in the same format, and have neighbour numbers: especially,
> + 'stw(m)' need be in the middle of 'stb' and 'std'.
> +
> + - for ((inst >> 26) != 0x3):
> +
> + stb: 0x18, or 0x19,
> + stw: 0x1a, stwm: 0x1b,
> + std: 0x1c.
> +
> + - else ((inst >> 26) == 0x3), need check :
> +
> + stb: 0x08, or 0x09,
> + stw: 0x0a,
> + std: 0x0b.
> +*/
>
> static int
> inst_saves_gr (unsigned long inst)
> {
> - /* Does it look like a stw? */
> + /* Does it look like a stw(m)? */
> if ((inst >> 26) == 0x1a || (inst >> 26) == 0x1b
> || (inst >> 26) == 0x1f
> - || ((inst >> 26) == 0x1f
> - && ((inst >> 6) == 0xa)))
> + || ((inst >> 26) == 0x3
> + && ((inst >> 6) & 0xf) == 0xa))
> return hppa_extract_5R_store (inst);
>
> /* Does it look like a std? */
> @@ -1394,16 +1413,12 @@ inst_saves_gr (unsigned long inst)
> && ((inst >> 6) & 0xf) == 0xb))
> return hppa_extract_5R_store (inst);
>
> - /* Does it look like a stwm? GCC & HPC may use this in prologues. */
> - if ((inst >> 26) == 0x1b)
> - return hppa_extract_5R_store (inst);
> -
> /* Does it look like sth or stb? HPC versions 9.0 and later use these
> too. */
> if ((inst >> 26) == 0x19 || (inst >> 26) == 0x18
> || ((inst >> 26) == 0x3
> && (((inst >> 6) & 0xf) == 0x8
> - || (inst >> 6) & 0xf) == 0x9))
> + || ((inst >> 6) & 0xf) == 0x9)))
> return hppa_extract_5R_store (inst);
>
> return 0;
>
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed