On 02/12/14 22:58, Ramana Radhakrishnan wrote:
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.
Done. It's similar to the aarch64 adrp+add case. It does make it easier
to read, thanks.
2014-12-04 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.
+ 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;
Done, but if/when we extend the function to handle more fusion cases it
will need to be
refactored, since we will want to just bail out of this MOVW+MOVT case
rather than the whole function.
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.
Here's the updated patch. I've tested on arm-none-eabi and made sure
that the
fusion still happens on the benchmarks I looked at.
Ok?
Thanks,
Kyrill
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.
