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Selective scheduling pass - target changes (ia64 & rs6000) [3/3]


Hello,

This patch shows the target dependent changes for the selective scheduler. The majority of changes is in the config/ia64/ia64.c file. They also include a lot of tunings done thorough the project. Each tuning originated from a problem test case (usually from SPEC or from Al Aburto tests) that was fixed by it. The summary of changes is as follows:

o speculation support is improved to allow more patterns to be speculative (speculable1 and speculable2 attributes mark patterns/alternatives that are valid for speculation);

o bundling also optimizes for minimal number of mid-bundle stops;

o we lower the priority of memory operations if we have issued too many of them on the current cycle;

o default function and loop alignment is set to 64 and 32, respectively;

o we discard cost of memory dependencies which are likely false;

o we place a stop bit after every simulated processor cycle;

o the incorrect bypass in itanium2.md that resulted in stalls between fma and st insns is removed.

Also, to support the proper alignment on scheduled loops, we have put pass_compute_alignments after pass_machine_reorg (this part actually is in the middle-end patch, but I mention it here as it was inspired by the Itanium).

The rs6000 change is a minimal version needed to support the selective scheduler for a target. As we now can have several points in a region at which we are scheduling, the backend can no longer save the scheduler state in private variables and use it in the hooks (e.g. last_scheduled_insn). For that purpose, a concept of a target context is introduced: all private scheduler-related target info should be put in there, and the target should provide hooks for creating/deleting/setting as current a target context. The scheduler then treats target contexts as opaque pointers. Also, we do not yet support adjust_priority hooks (but the work on this is underway), so that part of the rs6000 scheduler hooks is disabled.

OK for trunk?
Andrey


2008-06-03 Andrey Belevantsev <abel@ispras.ru> Dmitry Melnik <dm@ispras.ru> Dmitry Zhurikhin <zhur@ispras.ru> Alexander Monakov <amonakov@ispras.ru> Maxim Kuvyrkov <maxim@codesourcery.com>

* config/ia64/ia64.c: Include sel-sched.h. Rewrite speculation hooks.
(ia64_gen_spec_insn): Removed.
(get_spec_check_gen_function, insn_can_be_in_speculative_p,
ia64_gen_spec_check): New static functions.
(ia64_alloc_sched_context, ia64_init_sched_context,
ia64_set_sched_context, ia64_clear_sched_context,
ia64_free_sched_context, ia64_get_insn_spec_ds,
ia64_get_insn_checked_ds, ia64_skip_rtx_p): Declare functions.
(ia64_needs_block_p): Change prototype.
(ia64_gen_check): Rename to ia64_gen_spec_check.
(ia64_adjust_cost): Rename to ia64_adjust_cost_2. Add new parameter
into declaration, add special memory dependencies handling.
(TARGET_SCHED_ALLOC_SCHED_CONTEXT, TARGET_SCHED_INIT_SCHED_CONTEXT,
TARGET_SCHED_SET_SCHED_CONTEXT, TARGET_SCHED_CLEAR_SCHED_CONTEXT,
TARGET_SCHED_FREE_SCHED_CONTEXT, TARGET_SCHED_GET_INSN_SPEC_DS,
TARGET_SCHED_GET_INSN_CHECKED_DS, TARGET_SCHED_SKIP_RTX_P):
Define new target hooks.
(TARGET_SCHED_GEN_CHECK): Rename to TARGET_SCHED_GEN_SPEC_CHECK.
(ia64_override_options): Turn on selective scheduling with -O3,
disable -fauto-inc-dec. Initialize align_loops and align_functions
to 32 and 64, respectively. Set global selective scheduling flags
according to target-dependent flags.
(rtx_needs_barrier): Support UNSPEC_LDS_A.
(group_barrier_needed): Use new mstop-bit-before-check flag.
Add heuristic.
(dfa_state_size): Make global.
(spec_check_no, max_uid): Remove.
(mem_ops_in_group, current_cycle): New variables.
(ia64_sched_init): Disable checks for !SCHED_GROUP_P after reload.
Initialize new variables.
(is_load_p, record_memory_reference): New functions.
(ia64_dfa_sched_reorder): Lower priority of loads when limit is
reached.
(ia64_variable_issue): Change use of current_sched_info to
sched_deps_info. Update comment. Note if a load or a store is issued.
(ia64_first_cycle_multipass_dfa_lookahead_guard_spec): Require a cycle
advance if maximal number of loads or stores was issued on current
cycle.
(scheduled_good_insn): New static helper function.
(ia64_dfa_new_cycle): Assert that last_scheduled_insn is set when
a group barrier is needed. Fix vertical spacing. Guard the code
doing state transition with last_scheduled_insn check.


        Mark that a stop bit should be before current insn if there was a
        cycle advance.  Update current_cycle and mem_ops_in_group.
	(ia64_h_i_d_extended): Change use of current_sched_info to
        sched_deps_info. Reallocate stops_p by larger chunks.
	(struct _ia64_sched_context): New structure.
	(ia64_sched_context_t): New typedef.
	(ia64_alloc_sched_context, ia64_init_sched_context,
	ia64_set_sched_context, ia64_clear_sched_context,
	ia64_free_sched_context): New static functions.
	(gen_func_t): New typedef.
	(get_spec_load_gen_function): New function.
	(SPEC_GEN_EXTEND_OFFSET): Declare.	
	(ia64_set_sched_flags): Check common_sched_info instead of *flags.
	(get_mode_no_for_insn): Change the condition that prevents use of
	special hardware registers so it can now handle pseudos.
	(get_spec_unspec_code): New function.
	(ia64_skip_rtx_p, get_insn_spec_code, ia64_get_insn_spec_ds,
	ia64_get_insn_checked_ds, ia64_gen_spec_load): New static functions.
	(ia64_speculate_insn, ia64_needs_block_p): Support branchy checks
	during selective scheduling.
	(ia64_speculate_insn): Use ds_get_speculation_types when
	determining whether we need to change the pattern.
	(SPEC_GEN_LD_MAP, SPEC_GEN_CHECK_OFFSET): Declare.
	(ia64_spec_check_src_p): Support new speculation/check codes.
	(struct bundle_state): New field.
	(issue_nops_and_insn): Initialize it.
	(insert_bundle_state): Minimize mid-bundle stop bits.
	(important_for_bundling_p): New function.
	(get_next_important_insn): Use important_for_bundling_p.
	(bundling): When shifting TImode from unimportant insns, ignore
	also group barriers.  Assert that best state is found before
	the backward bundling pass.  Print number of mid-bundle stop bits.
	Minimize mid-bundle stop bits.  Check correct calculation of
	mid-bundle stop bits.
	(ia64_sched_finish, final_emit_insn_group_barriers): Fix formatting.
	(final_emit_insn_group_barriers): Emit stop bits before insns starting
	a new cycle.
	(sel2_run): New variable.
	(ia64_reorg): When flag_selective_scheduling is set, run the selective
	scheduling pass instead of schedule_ebbs.  Adjust for
	flag_selective_scheduling2.
	(ia64_optimization_options): Declare new parameter.
	
	* config/ia64/ia64.md (speculable1, speculable2): New attributes.
	(UNSPEC_LDS_A): New UNSPEC.
	(movqi_internal, movhi_internal, movsi_internal, movdi_internal,
	movti_internal, movsf_internal, movdf_internal,
	movxf_internal): Make visible.  Add speculable* attributes.
	(output_c_nc): New mode attribute.
	(mov<mode>_speculative_a, zero_extend<mode>di2_speculative_a,
	mov<mode>_nc, zero_extend<mode>di2_nc,
	advanced_load_check_nc_<mode>): New insns.
	(zero_extend*): Add speculable* attributes.

* config/ia64/ia64.opt (msched_fp_mem_deps_zero_cost): New option.
(msched-stop-bits-after-every-cycle): Likewise.
(mstop-bit-before-check): Likewise.
(msched-max-memory-insns,
msched-max-memory-insns-hard-limit): Likewise.
(msched-spec-verbose, msched-prefer-non-data-spec-insns,
msched-prefer-non-control-spec-insns, msched-count-spec-in-critical-path,
msel-sched-renaming, msel-sched-substitution, msel-sched-data-spec,
msel-sched-control-spec, msel-sched-dont-check-control-spec): Use Target
Report Var instead of Common Report Var.


	* config/ia64/itanium2.md: Remove strange bypass.
	
	* config/ia64/t-ia64 (ia64.o): Add dependency on sel-sched.h.

	* config/rs6000/rs6000.c (rs6000_init_sched_context,
	rs6000_alloc_sched_context, rs6000_set_sched_context,
	rs6000_free_sched_context): New functions.
	(struct _rs6000_sched_context): New.
	(rs6000_sched_reorder2): Do not modify INSN_PRIORITY for selective
	scheduling.
	(rs6000_sched_finish): Do not run for selective scheduling.

Attachment: sel-sched-merge-targets.diff.gz
Description: application/gzip


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