From: Nick Clifton <nickc@redhat.com>
To: Jeff Law <law@redhat.com>, Bernd Schmidt <bschmidt@redhat.com>,
gcc-patches@gcc.gnu.org
Subject: Re: RFC/RFA: Fix bug with REE optimization corrupting extended registers
Date: Fri, 20 Nov 2015 09:20:00 -0000 [thread overview]
Message-ID: <564EE5BE.4080409@redhat.com> (raw)
In-Reply-To: <564E1596.4070900@redhat.com>
Hi Jeff,
>> The code there would solve this problem, but the approach is is overly
>> cautious, since it disables the optimization for all extensions that
>> increase the number of hard registers used. Some of these will be
>> viable candidates, provided that the extra hard registers are no used.
>> (This is certainly true for the RL78, where the (patched) optimization
>> does improve code, even though the widening does use extra registers).
> Nick -- can you pass along your testcode?
Sure - this is for the RL78 toolchain. In theory the problem is
generic, but I have not tested other toolchains.
Compile the gcc.c-torture/execute/pr42833.c or
gcc.c-torture/execute/strct-stdarg-1.c tests at -O1 or higher with -free
also specified on the command line. Without -free these tests pass.
With -free they fail.
Cheers
Nick
next prev parent reply other threads:[~2015-11-20 9:20 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-18 14:15 Nick Clifton
2015-11-19 0:52 ` Bernd Schmidt
2015-11-19 1:56 ` Jeff Law
2015-11-19 15:34 ` Nick Clifton
2015-11-19 16:53 ` Bernd Schmidt
2015-11-19 17:06 ` Jeff Law
2015-11-19 17:18 ` Bernd Schmidt
2015-11-19 18:01 ` Jeff Law
2015-11-19 18:31 ` Jeff Law
2015-11-20 9:20 ` Nick Clifton [this message]
2015-11-20 17:32 ` Jeff Law
2015-11-20 22:01 ` Jeff Law
2015-11-20 22:10 ` Eric Botcazou
2015-11-19 19:25 ` Jeff Law
2015-11-20 22:28 ` Jeff Law
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