Re: [PATCH] MIPS: Fix the GCC version check for `__multi3' workaround

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Mon, Mar 30, 2026 at 02:54:09AM +0100, Maciej W. Rozycki wrote:
> It was only GCC 10 that fixed a MIPS64r6 code generation issue with a 
> `__multi3' libcall inefficiently produced to perform 64-bit widening 
> multiplication while suitable machine instructions exist to do such a 
> calculation.  The fix went in with GCC commit 48b2123f6336 ("re PR 
> target/82981 (unnecessary __multi3 call for mips64r6 linux kernel)").
> 
> Adjust our code accordingly, removing build failures such as:
> 
> mips64-linux-ld: lib/math/div64.o: in function `mul_u64_add_u64_div_u64':
> div64.c:(.text+0x84): undefined reference to `__multi3'
> 
> with the GCC versions affected.
> 
> Fixes: ebabcf17bcd7 ("MIPS: Implement __multi3 for GCC7 MIPS64r6 builds")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202601140146.hMLODc6v-lkp@intel.com/
> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
> Cc: stable@vger.kernel.org # v4.15+
> ---
>  arch/mips/lib/multi3.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

applied to mips-fixes

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]