Hi Ralf,

On Tue, Aug 17, 2021 at 1:55 PM Ralf Baechle [off-list ref] wrote:

On Tue, Aug 17, 2021 at 12:54:32PM +0100, Sudip Mukherjee wrote:

quoted

While I was testing v5.4.142-rc2 I noticed mips build of
decstation_r4k_defconfig fails with binutils-2_37. The error is:

arch/mips/dec/prom/locore.S: Assembler messages:
arch/mips/dec/prom/locore.S:29: Error: opcode not supported on this
processor: r4600 (mips3) `rfe'

I have also reported this at https://sourceware.org/bugzilla/show_bug.cgi?id=28241

It would appear gas got more anal about ISA checking for the RFE instructions
which did only exist in MIPS I and II; MIPS III and later use ERET for
returning from an exception.

The older gas I've got installed here happily accepts RFE in MIPS III/R4000
mode:

<snip>

It's easy to find arguments for why this gas change is the right thing to
do - and not the right thing to do.

It should be fixable by simply putting gas into mips1 mode.  Can you test
below patch?

Tested on top of v5.4.142-rc2 and it builds again. Thanks for the
quick reply and the patch.


-- 
Regards
Sudip