From: Iain Sandoe <developer@sandoe-acoustics.co.uk>
To: Eric Botcazou <ebotcazou@adacore.com>
Cc: David Miller <davem@davemloft.net>,
amodra@gmail.com, gcc-patches@gcc.gnu.org
Subject: Re: Reload related segfaults
Date: Thu, 27 Oct 2011 13:21:00 -0000 [thread overview]
Message-ID: <0566B4D4-2767-4C9E-93CB-44BF0D190771@sandoe-acoustics.co.uk> (raw)
In-Reply-To: <201110271233.22790.ebotcazou@adacore.com>
On 27 Oct 2011, at 11:33, Eric Botcazou wrote:
>> The crash is in find_valid_class() called from push_reload(), via
>> this
>> code block around line 1184 of reload.c:
>>
>> enum reg_class in_out_class
>> = find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
>> subreg_regno_offset (REGNO (SUBREG_REG (out)),
>> GET_MODE (SUBREG_REG (out)),
>> SUBREG_BYTE (out),
>> GET_MODE (out)),
>> REGNO (SUBREG_REG (out)));
>>
>> 'out' is:
>>
>> (subreg:DI (reg/v:V4QI 50 %f18 [orig:314 s2hi4_ ] [314]) 0)
>>
>> so subreg_regno_offset() returns -1, and find_valid_class() isn't
>> too happy
>> about getting "-1" for it's 'n' argument.
>
> OK, Alan's case is the same-sized and yours is the paradoxical one.
> Clearly we
> shouldn't have tried to change anything for them.
>
> Tentative fix attached, it should restore the old behavior for the
> cases where
> everything was working fine before. I'm going to give it some
> testing.
>
>
> PR rtl-optimization/46603
> * reload.c (push_reload): In the out case, restore previous behavior
> for subregs that don't have word mode.
powerpc darwin9 is also affected - I stage3-bubbled the patch above
and libjava built OK (full reg-strap is a long job).
Iain
next prev parent reply other threads:[~2011-10-27 13:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-27 6:20 Alan Modra
2011-10-27 6:28 ` David Miller
2011-10-27 8:46 ` David Miller
2011-10-27 12:01 ` Eric Botcazou
2011-10-27 13:21 ` Iain Sandoe [this message]
2011-10-27 19:18 ` Eric Botcazou
2011-11-04 13:44 ` Alan Modra
2011-11-04 17:02 ` Eric Botcazou
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