linux-mips
[Top] [All Lists]

Re: [patch] MIPS/gcc: Revert removal of DImode shifts for 32-bit targets

To: Richard Sandiford <rsandifo@redhat.com>
Subject: Re: [patch] MIPS/gcc: Revert removal of DImode shifts for 32-bit targets
From: Richard Henderson <rth@redhat.com>
Date: Fri, 3 Sep 2004 00:08:58 -0700
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>, Nigel Stephens <nigel@mips.com>, gcc-patches@gcc.gnu.org, linux-mips@linux-mips.org
In-reply-to: <87sm9zg7dg.fsf@redhat.com>
Mail-followup-to: Richard Henderson <rth@redhat.com>, Richard Sandiford <rsandifo@redhat.com>, "Maciej W. Rozycki" <macro@linux-mips.org>, Nigel Stephens <nigel@mips.com>, gcc-patches@gcc.gnu.org, linux-mips@linux-mips.org
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <876580bm2e.fsf@redhat.com> <410F60DF.9020400@mips.com> <Pine.LNX.4.58L.0408042123030.31930@blysk.ds.pg.gda.pl> <87r7qiwz54.fsf@redhat.com> <20040809220838.GE16493@redhat.com> <87zn5336h7.fsf@redhat.com> <20040810232020.GA21922@redhat.com> <87eklnw0g7.fsf@redhat.com> <20040903065331.GG20559@redhat.com> <87sm9zg7dg.fsf@redhat.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.4.1i
On Fri, Sep 03, 2004 at 08:05:15AM +0100, Richard Sandiford wrote:
>      However, on some machines, such as the 80386 and the 680x0, truncation
>      only applies to shift operations and not the (real or pretended)
>      bit-field operations.  Define @code{SHIFT_COUNT_TRUNCATED} to be zero on
>      such machines.  Instead, add patterns to the @file{md} file that include
>      the implied truncation of the shift instructions.
> 
> I was deliberately trying to avoid this fuzziness with the new target hook.

Hmm.  I suppose we could pass the shift operation in there; 
ASHIFT, LSHIFT, ZERO_EXTRACT, SIGN_EXTRACT.


r~

<Prev in Thread] Current Thread [Next in Thread>