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From: Jeff Law <law@redhat.com>
To: Bernd Edlinger <bernd.edlinger@hotmail.de>,
	"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH][ PR rtl-optimization/79286] Drop may_trap_p exception to testing dominance in update_equiv_regs
Date: Fri, 28 Apr 2017 19:01:00 -0000	[thread overview]
Message-ID: <713d5000-97b7-4933-3e4f-22d6de1331d3@redhat.com> (raw)
In-Reply-To: <AM4PR0701MB2162813D9C53F9CE4A39D624E4130@AM4PR0701MB2162.eurprd07.prod.outlook.com>

On 04/28/2017 11:27 AM, Bernd Edlinger wrote:
>>
> 
> Yes I agree, that is probably not worth it.  So I could try to remove
> the special handling of PIC+const and see what happens.
> 
> However the SYMBOL_REF_FUNCTION_P is another story, that part I would
> like to keep: It happens quite often, already w/o -fpic that call
> statements are using SYMBOL_REFs to ordinary (not weak) function
> symbols, and may_trap returns 1 for these call statements wihch is IMHO
> wrong.
Hmm, thinking more about this, wasn't the original case a PIC referrence 
for something like &x[BIGNUM].

Perhaps we could consider a PIC reference without other arithmetic as 
safe.  That would likely pick up the SYMBOL_REF_FUNCTION_P case you want 
as well good deal many more PIC references as non-trapping.

Jeff

  reply	other threads:[~2017-04-28 18:46 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-23 18:33 Bernd Edlinger
2017-04-28 17:17 ` Jeff Law
2017-04-28 18:05   ` Bernd Edlinger
2017-04-28 19:01     ` Jeff Law [this message]
2017-04-28 20:23       ` Bernd Edlinger
2017-04-28 20:27         ` Bernd Edlinger
2017-04-29  9:27       ` Bernd Edlinger
2017-05-12 16:49         ` [PING][PATCH][ " Bernd Edlinger
2017-06-01 16:00           ` [PING**2][PATCH][ " Bernd Edlinger
     [not found]           ` <59f99a5b-e5db-7078-5f55-c4b42f9c4a8b@hotmail.de>
2017-06-14 12:43             ` [PING**3][PATCH][ " Bernd Edlinger
2017-06-23  4:35         ` [PATCH][ " Jeff Law
  -- strict thread matches above, loose matches on Subject: below --
2017-02-24 15:48 Jeff Law

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