On 7/10/2022 12:19 PM, Roger Sayle wrote:
This patch builds upon Richard Biener's suggestion of avoiding global
variables to track state/identify which passes have already been run.
In the early middle-end, the tree-ssa passes use the curr_properties
field in cfun to track this. This patch uses a new rtl_pass_progress
int field in crtl to do something similar.
This patch allows the global variables lra_in_progress, reload_in_progress,
reload_completed, epilogue_completed and regstack_completed to be removed
from rtl.h and implemented as bits within the new crtl->rtl_pass_progress.
I've also taken the liberty of adding a new combine_completed bit at the
same time [to respond the Segher's comment it's easy to change this to
combine1_completed and combine2_completed if we ever perform multiple
combine passes (or multiple reload/regstack passes)]. At the same time,
I've also refactored bb_reorder_complete into the same new field;
interestingly bb_reorder_complete was already a bool in crtl.
One very minor advantage of this implementation/refactoring is that the
predicate "can_create_pseudo_p ()" which is semantically defined to be
!reload_in_progress && !reload_completed, can now be performed very
efficiently as effectively the test (progress & 12) == 0, i.e. a single
test instruction on x86.
For consistency, I've also moved cse_not_expected (the last remaining
global variable in rtl.h) into crtl, as its own bool field.
The vast majority of this patch is then churn to handle these changes.
Thanks to macros, most code is unaffected, assuming it treats those
global variables as r-values, though some source files required/may
require tweaks as these "variables" are now defined in emit-rtl.h
instead of rtl.h.
This patch has been tested on x86_64-pc-linux-gnu with make bootstrap
and make -k check, both with and without --target_board=unix{-m32},
with no new failures. Might this clean-up be acceptable in stage 1,
given the possible temporary disruption transitioning some backends?
I'll start checking various backends myself with cross-compilers, but if
Jeff Law could spin this patch on his build farm, that would help
identify targets that need attention.
2022-07-10 Roger Sayle <ro...@nextmovesoftware.com>
gcc/ChangeLog
* bb-reorder.cc (reorder_basic_blocks): bb_reorder_complete is
now a bit in crtl->rtl_pass_progress.
* cfgrtl.cc (rtl_split_edge): Likewise.
(fixup_partitions): Likewise.
(verify_hot_cold_block_grouping): Likewise.
(cfg_layout_initialize): Likewise.
* combine.cc (rest_of_handle_combine): Set combine_completed
bit in crtl->rtl_pass_progress.
* cse.cc (rest_of_handle_cse): cse_not_expected is now a field
in crtl.
(rest_of_handle_cse2): Likewise.
(rest_of_handle_cse_after_global_opts): Likewise.
* df-problems.cc: Include emit-rtl.h to access RTL pass progress
variables.
* emit-rtl.h (PROGRESS_reload_completed): New bit masks.
(rtl_data::rtl_pass_progress): New integer field to track progress.
(rtl_data::bb_reorder_complete): Delete, no part of
rtl_pass_progress.
(rtl_data::cse_not_expected): New bool field, previously a global
variable.
(crtl_pass_progress): New convience macro.
(combine_completed): New macro.
(lra_in_progress): New macro replacing global variable.
(reload_in_progress): Likewise.
(reload_completed): Likewise.
(bb_reorder_complete): New macro replacing bool field in crtl.
(epilogue_completed): New macro replacing global variable.
(regstack_completed): Likewise.
(can_create_pseudo_p): Move from rtl.h and update definition.
* explow.cc (memory_address_addr_space): cse_not_expected is now
a field in crtl.
(use_anchored_address): Likewise.
* final.c (rest_of_clean_state): Reset crtl->rtl_pass_progress
to zero.
* function.cc (prepare_function_start): cse_not_expected is now
a field in crtl.
(thread_prologue_and_epilogue_insns): epilogue_completed is now
a bit in crtl->rtl_pass_progress.
* ifcvt.cc (noce_try_cmove_arith): cse_not_expected is now a
field in crtl.
* lra-eliminations.cc (init_elim_table): lra_in_progress is now
a bit in crtl->rtl_pass_progress.
* lra.cc (lra_in_progress): Delete global variable.
(lra): lra_in_progress and reload_completed are now bits in
crtl->rtl_pass_progress.
* modulo-sched.cc (sms_schedule): reload_completed is now a bit
in crtl->rtl_pass_progress.
* passes.cc (skip_pass): reload_completed and epilogue_completed
are now bits in crtl->rtl_pass_progress.
* recog.cc (reload_completed): Delete global variable.
(epilogue_completed): Likewise.
* reg-stack.cc (regstack_completed): Likewise.
(rest_of_handle_stack_regs): regstack_completed is now a bit in
crtl->rtl_pass_progress.
* regstat.cc: Include memmodel.h and emit-rtl.h to access RTL
pass progress variables.
* reload1.cc (reload_in_progress): Delete global variable.
(reload): reload_in_progress and reload_completed are now bits
in crtl->rtl_pass_progress.
* rtl.h (reload_completed): Delete global variable prototype.
(epilogue_completed): Likewise.
(reload_in_progress): Likewise.
(lra_in_progress): Likewise.
(can_create_pseudo_p): Delete, moved to emit-rtl.h.
(regstack_completed): Delete global variable prototype.
(cse_not_expected): Likewise.
* sched-ebb.cc: Include memmodel.h and emit-rtl.h to access RTL
pass progress variables.
* config/i386/x86-tune-sched-atom.cc: Include memmodel.h and
emit-rtl.h to access RTL pass progress variables.
* config/i386/x86-tune-sched.cc: Likewise.
So we need a #include "emit-rtl.h" generated by genpeep.cc and
genconditions.cc which fixes a number of targets.
Several targets use reload_completed, epilogue_completed as lvalues and
will need updating (microblaze, sh, likely others). Most should be
complete by this time tomorrow.
Jeff
