Re: Question about doloop_end pattern

[Ian Lance Taylor <iant at google dot com>]

"Bingfeng Mei" <bmei@broadcom.com> writes:

> I tried to use doloop_end pattern to reduce loop overhead for our target
> processor, which features a dedicated loop instruction.  Somehow even a
> simple loop just cannot pass the test of doloop_condition_get, which
> requires following canonical pattern.

You are looking at this at the wrong level.  That comment is
describing what your doloop insn must look like in the MD file.  It
does not mean that the RTL for the loop must look like that in order
for the doloop optimization to apply.  Look at existing targets which
support doloops for examples of how to write the insn.

Ian