From: "Philippe De Muyter" <phdm@macqel.be>
To: binutils mailing list <binutils@sources.redhat.com>
Subject: m68k : why is bra an alias for braw, not jra
Date: Tue, 21 Mar 2006 11:01:00 -0000 [thread overview]
Message-ID: <200603211006.k2LA6w721722@mail.macqel.be> (raw)
All,
In the m68k assembler, I wonder why `bra' and friends are alias for their
`bxxw' counterparts.
It seems to me that if someone needs a word-sized bra insn, (s)he will
use the braw variant.
And if one writes no size specification for a `bra' instruction the assembler
should be free to choose the most efficient way to generate it, i.e.
a `brab' if possible of even a `bral' if needed.
IIRC, that's also what the Motorola assembler did in Motorola's Unix System V.
It is also what `gcc/config/m68k/lb1sf68.asm' expects in gcc. If you look
at this file, you'll see that it is full of `bra', `beq', `bge' etc., where
the intent is clearly to let the assembler decide.
I know that there exists a `jra' or `jbra' keyword, but that's not the
natural way of writing if you write assembler code using your Motorola
reference manual as base.
If no-one objects, I'll submit a patch
Philippe
next reply other threads:[~2006-03-21 10:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-21 11:01 Philippe De Muyter [this message]
2006-04-07 15:37 ` Nick Clifton
2006-04-07 15:53 ` Dave Korn
2006-04-07 16:48 ` Andreas Schwab
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