[PATCH] Flag to enable IEEE-754 friendly FP optimizations

[Sergey Dmitrouk]

Ping.

> Hal, do I get it right that what you suggest can be implemented in
> Instruction::mayReadFromMemory() and Instruction::mayWriteToMemory() to
> get desired behaviour in wider range of usages?

I guess no, because updating these two functions didn't change anything.

-- 
Sergey

On Fri, Oct 31, 2014 at 06:19:40PM +0200, Sergey Dmitrouk wrote:
> Ping.  Rebased patches with a fix for a typo (in code, not in comments) are
> attached.
> 
> Hal, do I get it right that what you suggest can be implemented in
> Instruction::mayReadFromMemory() and Instruction::mayWriteToMemory() to
> get desired behaviour in wider range of usages?
> 
> Thanks,
> Sergey
> 
> On Fri, Oct 24, 2014 at 09:24:48AM -0700, Stephen Canon wrote:
> >      On Oct 24, 2014, at 12:23 PM, Hal Finkel <hfinkel at anl.gov> wrote:
> > 
> >      ----- Original Message -----
> > 
> >        From: "Stephen Canon" <scanon at apple.com>
> >        To: "Hal Finkel" <hfinkel at anl.gov>
> >        Cc: "Sergey Dmitrouk" <sdmitrouk at accesssoftek.com>, "llvm-commits"
> >        <llvm-commits at cs.uiuc.edu>, "Owen Anderson"
> >        <owen at apple.com>
> >        Sent: Friday, October 24, 2014 11:13:10 AM
> >        Subject: Re: [PATCH] Flag to enable IEEE-754 friendly FP optimizations
> > 
> >        As a necessary piece of building support for FENV_ACCESS, yes, I
> >        think this is worth pursuing.  Note, however, that actually
> >        providing full FENV_ACCESS support is likely to be a significant
> >        undertaking, and I expect that the pieces that go into it are
> >        basically useless until all of them are in place.  Thata**s not to say
> >        that it isna**t worth doing, just that ita**s a big thankless job.
> > 
> >      Steve, so long as you're willing to serve as the expert reviewer here,
> >      I'm happy to help move this forward as well. We should, however,
> >      probably have a plan for the rest of it. Maybe this is as simple as:
> >      when FP exceptions are enabled, we treat all FP operations as if they
> >      might write to memory (except that AA confirms that they don't actually
> >      alias with any address in particular, but we say nothing about function
> >      calls). What do you think?
> > 
> >    From a numerical point of view, something along those lines could be
> >    workable, yes.
> >    a** Steve