How to set up gcc for a strange machine...

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Article #51408

#51408

From: M Y Ben Gershon
Date: Sun, 30 May 1993 06:01

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I have come across a very strange problem when trying to get the gcc
floating point support working on the ARM processor.  Everything in the ARM
in LITTLE_ENDIAN.  There is no doubt about that.  That means long integers
(ie 64 bit double words) and so on.  HOWEVER, floating point data is stored
in BIG_ENDIAN format!  By that I mean that the (32 bit) word with the sign
etc is in the LOWEST address, and the lower bits of the mantissa are in the
HIGHER ADDRESS.  Within each word, the order is LITTLE_ENDIAN.  I tried
altering WORDS_BIG_ENDIAN and HOST_WORDS_BIG_ENDIAN but that didn't help - it
messed up the register allocations as far as I can see.  I managed to get part
of the way there, but then found that when a floating point constant (double)
was split into two ints they were the wrong way round.  That only happened
when optimization was enabled.

Does anyone know of any way round this problem?  Has it appeared on any
other processor?  I am using gcc 2.4.1.

Michael Ben-Gershon
mybg@doc.ic.ac.uk

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From: mybg@doc.ic.ac.uk (M Y Ben Gershon)
Newsgroups: gnu.gcc.help
Subject: How to set up gcc for a strange machine...
Date: 30 May 1993 07:01:57 +0100
Organization: Department of Computing, Imperial College, University of London, UK.
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