* m68k -- extb.l instruction
@ 1996-03-21 12:33 Joel Sherrill
1996-03-21 13:00 ` Ian Lance Taylor
0 siblings, 1 reply; 2+ messages in thread
From: Joel Sherrill @ 1996-03-21 12:33 UTC (permalink / raw)
To: gas2
While incorporating a 68360 board support package into RTEMS and updating
tools, I tripped across this and wanted some feedback. For CPUs w/o a
bfffo instruction RTEMS has an SW implementation of bfffo which uses an
extb.l instruction. This worked correctly AFAIK for the 68000 and 68302
based BSPs using binutils 2.5.2. As of binutils 2.6, this instruction was
restricted to 020up and cpu32 which agrees with the m68k family
programmer's reference manual. But this leaves me confused -- what was
actually being generated binutils 2.5.2 on the 68000/68302? The code it
generated worked. Is this a hole in the m68k docs or just a fluke? Does
this instruction really exist on the 68302?
Just curious.
--joel
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: m68k -- extb.l instruction
1996-03-21 12:33 m68k -- extb.l instruction Joel Sherrill
@ 1996-03-21 13:00 ` Ian Lance Taylor
0 siblings, 0 replies; 2+ messages in thread
From: Ian Lance Taylor @ 1996-03-21 13:00 UTC (permalink / raw)
To: joel; +Cc: gas2
Date: Thu, 21 Mar 1996 14:04:28 -0600 (CST)
From: Joel Sherrill <joel@merlin.gcs.redstone.army.mil>
While incorporating a 68360 board support package into RTEMS and updating
tools, I tripped across this and wanted some feedback. For CPUs w/o a
bfffo instruction RTEMS has an SW implementation of bfffo which uses an
extb.l instruction. This worked correctly AFAIK for the 68000 and 68302
based BSPs using binutils 2.5.2. As of binutils 2.6, this instruction was
restricted to 020up and cpu32 which agrees with the m68k family
programmer's reference manual. But this leaves me confused -- what was
actually being generated binutils 2.5.2 on the 68000/68302? The code it
generated worked. Is this a hole in the m68k docs or just a fluke? Does
this instruction really exist on the 68302?
As far as I can see from the sources, gas has always restricted the
extb.l instruction to 68020up and cpu32. This did not change between
the 2.5.2 and 2.6 releases. I don't know why it was working for you
for 2.5.2.
Ian
^ permalink raw reply [flat|nested] 2+ messages in thread
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1996-03-21 12:33 m68k -- extb.l instruction Joel Sherrill
1996-03-21 13:00 ` Ian Lance Taylor
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