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Re: [PATCH 2/4] S12Z: GAS: Issue warning if TFR/EXG have identical source and destination.
- From: Nick Clifton <nickc at redhat dot com>
- To: John Darrington <john at darrington dot wattle dot id dot au>, binutils at sourceware dot org
- Date: Fri, 1 Feb 2019 10:51:03 +0000
- Subject: Re: [PATCH 2/4] S12Z: GAS: Issue warning if TFR/EXG have identical source and destination.
- References: <20190131180442.31410-1-john@darrington.wattle.id.au> <20190131180442.31410-2-john@darrington.wattle.id.au>
Hi John,
> It is permissible for the source and destination operands of TFR and EXG to be
> the same register. However it is a pointless instruction and anyone writing it
> has probably made a mistake.
I don't suppose that the ISA designers intended that this sort of instruction be
treated as a NOP, with the idea that in future ISA extensions they might be given
new semantics ?
> gas/
> * config/tc-s12z.c (tfr): Emit warning if operands are the same.
> * testsuite/gas/s12z/exg.d: New test case.
> * testsuite/gas/s12z/exg.l: New file.
Approved - please apply.
Cheers
Nick