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Message
From: fredrik@w...<fredrik@w...>
Date: Sat Dec 27 22:49:40 CET 2003
Subject: [openrisc] or32-gcc: Current status + new version
> The problems I've seen happen with double integer types. eCos uses
> them
> a lot.
I've have problems with 64-bit types (unsigned long long) also with
GCC3.2.x and GCC3.3.x, this when compiling ARM-code with arm-elf-gcc
target and -O2. I think its the GCC optimizer that is buggy, not
especially OR related maybe.
I think that what happened when compiling 64-bit arithmetic for an
32-bit processor, the operation is divided into two 32-bit
instructions. The optimizer seems to allow reordering of the latter
instruction, which in some cases can cause that the 64-bit result is
used before its completely calculated. Only the first 32-bit half is
done when its used.
It would be interesting to compile your sample code also for other
GCC-targets. Maybe this is something rather for the GCC-team to look into?
Best Regards,
/Fredrik Hederstierna
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