On Tue, Nov 11, 2014 at 11:55 AM, Kyrill Tkachov <kyrylo.tkac...@arm.com> wrote:
> Hi all,
>
> This is the arm implementation of the macro fusion hook.
> It tries to fuse movw+movt operations together. It also tries to take lo_sum
> RTXs into account since those generate movt instructions as well.
>
> Bootstrapped and tested on arm-none-linux-gnueabihf.
>
> Ok for trunk?
> if (current_tune->fuseable_ops & ARM_FUSE_MOVW_MOVT)
>+ {
>+ /* We are trying to fuse
>+ movw imm / movt imm
>+ instructions as a group that gets scheduled together. */
>+
A comment here about the insn structure would be useful.
>+ set_dest = SET_DEST (curr_set);
>+ if (GET_CODE (set_dest) == ZERO_EXTRACT)
>+ {
>+ if (CONST_INT_P (SET_SRC (curr_set))
>+ && CONST_INT_P (SET_SRC (prev_set))
>+ && REG_P (XEXP (set_dest, 0))
>+ && REG_P (SET_DEST (prev_set))
>+ && REGNO (XEXP (set_dest, 0)) == REGNO (SET_DEST (prev_set)))
>+ return true;
>+ }
>+ else if (GET_CODE (SET_SRC (curr_set)) == LO_SUM
>+ && REG_P (SET_DEST (curr_set))
>+ && REG_P (SET_DEST (prev_set))
>+ && GET_CODE (SET_SRC (prev_set)) == HIGH
>+ && REGNO (SET_DEST (curr_set)) == REGNO (SET_DEST (prev_set)))
>+ {
>+ return true;
>+ }
Can we add a fast path exit to be
if (GET_MODE (set_dest) != SImode)
return false;
I did think whether we wanted to use reg_overlap_mentioned_p as that
may simplify the logic a bit but that's overkill here as we still
want to restrict it to the cases above.
Otherwise OK.
Ramana
>+ }
>+ return false;
>
> Thanks,
> Kyrill
>
> 2014-11-11 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
>
> * config/arm/arm-protos.h (tune_params): Add fuseable_ops field.
> * config/arm/arm.c (arm_macro_fusion_p): New function.
> (arm_macro_fusion_pair_p): Likewise.
> (TARGET_SCHED_MACRO_FUSION_P): Define.
> (TARGET_SCHED_MACRO_FUSION_PAIR_P): Likewise.
> (ARM_FUSE_NOTHING): Likewise.
> (ARM_FUSE_MOVW_MOVT): Likewise.
> (arm_slowmul_tune, arm_fastmul_tune, arm_strongarm_tune,
> arm_xscale_tune, arm_9e_tune, arm_v6t2_tune, arm_cortex_tune,
> arm_cortex_a8_tune, arm_cortex_a7_tune, arm_cortex_a15_tune,
> arm_cortex_a53_tune, arm_cortex_a57_tune, arm_cortex_a9_tune,
> arm_cortex_a12_tune, arm_v7m_tune, arm_v6m_tune, arm_fa726te_tune
> arm_cortex_a5_tune): Specify fuseable_ops value.
