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From: Jeffrey A Law <law@cygnus.com>
To: hjl@lucon.org (H.J. Lu)
Cc: egcs@cygnus.com
Subject: Re: egcs-problem 1.0.2
Date: Sun, 05 Apr 1998 21:29:00 -0000	[thread overview]
Message-ID: <4739.891804156@hurl.cygnus.com> (raw)
In-Reply-To: <m0yLupl-00058JC@ocean.lucon.org>

  In message < m0yLupl-00058JC@ocean.lucon.org >you write:
  > > 
  > > 
  > >   In message < m0yLuSz-00058iC@ocean.lucon.org >you write:
  > >   > > This is the "linux asm" problem that I haven't been able to look at
  > >   > > for the last month or so due to personal and company commitments.
  > >   > > 
  > >   > > Basically there's a couple problems:
  > >   > > 
  > >   > >   * The linux x86 asm for strstr is totally bogus.
  > >   > 
  > >   > Does the code below make sense?
  > > Not sure what you're asking.  If you want I can resend the analysis.
  > > Basically the clobbers are bogus and the asm itself uses too many
  > > registers to be safely compiled.
  > > 
  > 
  > Why the clobbers are bogus? I changed one constraint from "g" to "m".
  > It seems to work fine for me. As long as the asm statement specifies
  > them as the clobbers and egcs doesn't use them inside the asm statement,
  > how can number of registers used in the asm statement be a problem with
  > egcs?
inputs and clobbers may not overlap.  The way to do what they want to
do is via matching input/output with an earlyclobber.

Additionally operands may come from memory which is accessed via
reg+reg addressing modes which will cause the compiler to run out
of asms.  This is the case even when the operand specifies a register
(it may need to be reloaded from a reg+reg address).

I've already discussed this at length with the Linux folks.

jeff

      reply	other threads:[~1998-04-05 21:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <19980331132837.33334@knorke.saar.de>
1998-04-04 20:05 ` H.J. Lu
1998-04-05 21:29   ` Jeffrey A Law
1998-04-05 21:29     ` H.J. Lu
1998-04-05 17:27       ` Jeffrey A Law
1998-04-05 17:27         ` H.J. Lu
1998-04-05 21:29           ` Jeffrey A Law [this message]

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