This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: [PATCH] Fix multiply-add regressions after expand-from-SSA

From: Paolo Bonzini <bonzini at gnu dot org>
To: Richard Guenther <rguenther at suse dot de>
Cc: Adam Nemet <anemet at caviumnetworks dot com>, gcc-patches at gcc dot gnu dot org, matz at suse dot de
Date: Thu, 30 Apr 2009 11:49:28 +0200
Subject: Re: [PATCH] Fix multiply-add regressions after expand-from-SSA
Newsgroups: gmane.comp.gcc.patches
References: <18937.21623.513246.348749@ropi.home> <alpine.LNX.2.00.0904301022430.25789@zhemvz.fhfr.qr> <alpine.LNX.2.00.0904301051470.25789@zhemvz.fhfr.qr>

> Actually the helper could look like

Couldn't this lead to wrong code for

a_1 = b_1 * c_1;
b_2 = b_1 + 1.0;
c_3 = b_2 + a_1;

where b_1 and b_2 could be assigned to the same partition and so the
final result would be "b_2 + b_2 * c_1"?

Paolo

Follow-Ups:
- Re: [PATCH] Fix multiply-add regressions after expand-from-SSA
  - From: Richard Guenther
- Re: [PATCH] Fix multiply-add regressions after expand-from-SSA
  - From: Michael Matz

References:
- [PATCH] Fix multiply-add regressions after expand-from-SSA
  - From: Adam Nemet
- Re: [PATCH] Fix multiply-add regressions after expand-from-SSA
  - From: Richard Guenther
- Re: [PATCH] Fix multiply-add regressions after expand-from-SSA
  - From: Richard Guenther

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]