From: Jeffrey A Law <law@cygnus.com>
To: Richard Henderson <rth@cygnus.com>
Cc: egcs@cygnus.com
Subject: Re: alpha failure on 920810-1
Date: Wed, 06 May 1998 23:49:00 -0000 [thread overview]
Message-ID: <24630.894510594@hurl.cygnus.com> (raw)
In-Reply-To: <19980427014147.34497@dot.cygnus.com>
In message <19980427014147.34497@dot.cygnus.com>you write:
> The correct transformation would be to retain the compare and base
> the conditional move off of that:
>
> (insn 9 8 10 (set (reg:DF 69)
> (eq:DF (reg/v:DF 68)
> (const_double:DF (cc0) 0 0))) -1 (nil)
> (nil))
>
> (insn 25 23 15 (set (reg/v:DF 68)
> (if_then_else:DF (ne (reg:DF 69)
> (const_double:DF (cc0) 0 0))
> (reg:DF 48 $f16)
> (reg:DF 72))) -1 (nil)
> (nil))
I wonder if you could effectively do this at insn output time?
The problem is you can end up with redundant compares. You could
use the machine dependent reorg pass to try and clean up some of
the redundant comparisons.
Just thinking outloud...
jeff
prev parent reply other threads:[~1998-05-06 23:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-04-27 1:41 Richard Henderson
1998-04-27 8:47 ` Joern Rennecke
1998-04-27 13:59 ` Richard Henderson
1998-04-28 22:14 ` Jim Wilson
1998-04-29 2:20 ` Richard Henderson
1998-04-29 12:27 ` Jim Wilson
1998-04-29 16:08 ` Joern Rennecke
1998-04-29 22:57 ` Richard Henderson
1998-04-30 10:25 ` Joern Rennecke
1998-04-30 13:20 ` Richard Henderson
1998-04-30 22:29 ` Richard Henderson
1998-05-08 16:08 ` Jeffrey A Law
1998-05-09 2:05 ` Richard Henderson
1998-05-06 23:49 ` Jeffrey A Law [this message]
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