Re: [PATCH v2] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions

From: Måns Rullgård
Date: Sat Nov 09 2013 - 13:20:49 EST


Matt Sealey <neko@xxxxxxxxxxxxx> writes:

> BTW has there been any evaluation of the penalty for the extra
> branching, or the performance hit for the ARMv7-without-division
> cases?

The branches themselves probably have minimal overhead. There will
however be code to preserve call-clobbered registers (and move the
values to/from r0/r1) that would not be needed if the div instructions
were done inline (obviously such a kernel could only run on hardware
with division support).

--
Måns Rullgård
mans@xxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/