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Host/Target confusion in Dwarf output
- From: Michael Eager <eager at eagercon dot com>
- To: GCC <gcc at gcc dot gnu dot org>
- Date: Thu, 12 Jul 2007 09:23:22 -0700
- Subject: Host/Target confusion in Dwarf output
I was looking through dwarf2out.c, tracking down the
cause for different assembly code being generated
when gcc was run on 32-bit and 64-bit hosts.
In dwarf2out.c, there are several places where decisions
about what to generate in the .s file are based on
HOST_BITS_PER_WIDE_INT or HOST_BITS_PER_WIDE_LONG or
similar. For example, when generating a long long value,
on a 32-bit host, the *target* assembly code will contain
two .4byte ops, while on a 64-bit host, a single .8byte
op is generated. There are a number of other differences.
The assembler for a 32-bit target might not have a .8byte
operator. So, when run on a 32-bit host, everything is OK.
On a 64-bit host, the assembly fails.
It seems to me that the same assembly code should be generated
independent of whether gcc is run on a 32-bit or 64-bit
host and all of these HOST_* tests should actually be
target domain parameters, like BITS_PER_WORD.
Michael Eager email@example.com
1960 Park Blvd., Palo Alto, CA 94306 650-325-8077