On 8/7/19 12:16 PM, Richard Sandiford wrote:
> The main IRA routine includes the code:
>
> /* Don't move insns if live range shrinkage or register
> pressure-sensitive scheduling were done because it will not
> improve allocation but likely worsen insn scheduling. */
> if (optimize
> && !flag_live_range_shrinkage
> && !(flag_sched_pressure && flag_schedule_insns))
> combine_and_move_insns ();
>
> The comment about not moving insns for pressure-sensitive scheduling
> makes sense, but I think the combine part of combine_and_move_insns is
> still useful, since it's folding a set of an equivalent value into its
> single user and so eliminates the need for one register altogether.
>
> (That also means that it's likely to undo live range shrinkage in
> some cases, so I think the blanket skip still makes sense there.)
>
> Tested on aarch64-linux-gnu, aarch64_be-elf and x86_64-linux-gnu.
> OK to install?
>
> Richard
>
>
> 2019-08-07 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * ira.c (combine_and_move_insns): Don't move insns if
> pressure-sensitive scheduling is enabled.
> (ira): Remove check for pressure-sensitive scheduling here.
>
> gcc/testsuite/
> * gcc.target/aarch64/csinc-3.c: New test.
> * gcc.target/aarch64/csinv-2.c: Likewise.
OK
jeff
