From: Jim Wilson <wilson@specifix.com>
To: DJ Delorie <dj@redhat.com>
Cc: iant@google.com, gcc@gcc.gnu.org
Subject: Re: hard_regno_nregs == 0 ?
Date: Wed, 09 Jan 2008 20:18:00 -0000 [thread overview]
Message-ID: <47852BE9.9010709@specifix.com> (raw)
In-Reply-To: <200801091647.m09Gl4Qp021266@greed.delorie.com>
DJ Delorie wrote:
> Are there any ports besides m32c that have registers which can hold HI
> (or SI I suppose) but not QI values?
IA-64 has branch registers that are only allowed to hold DImode values.
We use CANNOT_CHANGE_MODE_CLASS to enforce this.
On x86, the vector registers can hold SImode, but do not allow
HImode/QImode loads, and again CANNOT_CHANGE_MODE_CLASS is used to
enforce this.
I'm sure that there are other examples out there.
--
Jim Wilson, GNU Tools Support, http://www.specifix.com
next prev parent reply other threads:[~2008-01-09 20:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-08 20:13 DJ Delorie
2008-01-09 16:43 ` Ian Lance Taylor
2008-01-09 16:47 ` DJ Delorie
2008-01-09 16:56 ` Ian Lance Taylor
2008-01-09 20:18 ` Jim Wilson [this message]
2008-01-09 19:27 ` Jim Wilson
2008-01-09 20:39 ` DJ Delorie
2008-01-09 21:48 ` Paul Brook
2008-01-09 22:02 ` DJ Delorie
2008-01-11 0:12 ` Jim Wilson
2008-01-11 0:16 ` DJ Delorie
2008-01-12 0:48 ` Jim Wilson
2008-01-21 22:41 ` DJ Delorie
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