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Re: How to support 40bit GP register

From: Richard Henderson <rth at redhat dot com>
To: Mohamed Shafi <shafitvm at gmail dot com>
Cc: GCC <gcc at gcc dot gnu dot org>
Date: Wed, 04 Nov 2009 08:39:01 -0800
Subject: Re: How to support 40bit GP register
References: <ba0bd44d0910210725qc90b297g187f8d8712e2520f@mail.gmail.com> <4ADF95DD.8090202@redhat.com> <ba0bd44d0911040534j75864238w2883af552b62cd61@mail.gmail.com>

On 11/04/2009 05:34 AM, Mohamed Shafi wrote:

Load-store uses 32bits. Sign extension happens automatically. So i
have choosen INT_MODE (RI, 5) and copied movsi and renamed it to
movri. I have also specified that RImode need only one register.

This isn't going to work. In order to get correct code, you're going to need to be able to spill and reload the full 40-bit value.

If you can't do this easily... then I'm afraid we'll have to find a more complicated solution which involves only exposing RImode values after register allocation.

internal compiler error: in immed_double_const, at emit-rtl.c:553

Hmm. This is a nasty little logic error. The quickest work-around for the problem is to set need_64bit_hwint in config.gcc.

r~

References:
- Re: How to support 40bit GP register
  - From: Mohamed Shafi

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