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Selective scheduling pass - target changes (ia64 & rs6000) [3/3]
- From: Andrey Belevantsev <abel at ispras dot ru>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Jim Wilson <wilson at tuliptree dot org>, Vladimir Makarov <vmakarov at redhat dot com>, Ayal Zaks <ZAKS at il dot ibm dot com>
- Date: Tue, 03 Jun 2008 18:19:35 +0400
- Subject: Selective scheduling pass - target changes (ia64 & rs6000) [3/3]
- References: <4845522C.3010006@ispras.ru>
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.
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