| /* Scanning of rtl for dataflow analysis. |
| Copyright (C) 2007-2019 Free Software Foundation, Inc. |
| Contributed by Kenneth Zadeck (zadeck@naturalbridge.com). |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "rtl.h" |
| #include "predict.h" |
| #include "df.h" |
| #include "regs.h" |
| |
| |
| struct regstat_n_sets_and_refs_t *regstat_n_sets_and_refs; |
| |
| /*---------------------------------------------------------------------------- |
| REG_N_SETS and REG_N_REFS. |
| ----------------------------------------------------------------------------*/ |
| |
| /* If a pass need to change these values in some magical way or the |
| pass needs to have accurate values for these and is not using |
| incremental df scanning, then it should use REG_N_SETS and |
| REG_N_USES. If the pass is doing incremental scanning then it |
| should be getting the info from DF_REG_DEF_COUNT and |
| DF_REG_USE_COUNT. */ |
| |
| void |
| regstat_init_n_sets_and_refs (void) |
| { |
| unsigned int i; |
| unsigned int max_regno = max_reg_num (); |
| |
| timevar_push (TV_REG_STATS); |
| df_grow_reg_info (); |
| gcc_assert (!regstat_n_sets_and_refs); |
| |
| regstat_n_sets_and_refs = XNEWVEC (struct regstat_n_sets_and_refs_t, max_regno); |
| |
| if (MAY_HAVE_DEBUG_BIND_INSNS) |
| for (i = 0; i < max_regno; i++) |
| { |
| int use_count; |
| df_ref use; |
| |
| use_count = DF_REG_USE_COUNT (i); |
| for (use = DF_REG_USE_CHAIN (i); use; use = DF_REF_NEXT_REG (use)) |
| if (DF_REF_INSN_INFO (use) && DEBUG_INSN_P (DF_REF_INSN (use))) |
| use_count--; |
| |
| |
| SET_REG_N_SETS (i, DF_REG_DEF_COUNT (i)); |
| SET_REG_N_REFS (i, use_count + REG_N_SETS (i)); |
| } |
| else |
| for (i = 0; i < max_regno; i++) |
| { |
| SET_REG_N_SETS (i, DF_REG_DEF_COUNT (i)); |
| SET_REG_N_REFS (i, DF_REG_USE_COUNT (i) + REG_N_SETS (i)); |
| } |
| timevar_pop (TV_REG_STATS); |
| |
| } |
| |
| |
| /* Free the array that holds the REG_N_SETS and REG_N_REFS. */ |
| |
| void |
| regstat_free_n_sets_and_refs (void) |
| { |
| gcc_assert (regstat_n_sets_and_refs); |
| free (regstat_n_sets_and_refs); |
| regstat_n_sets_and_refs = NULL; |
| } |
| |
| |
| /*---------------------------------------------------------------------------- |
| REGISTER INFORMATION |
| |
| Process REG_N_DEATHS, REG_N_CALLS_CROSSED, and REG_BASIC_BLOCK. |
| |
| ----------------------------------------------------------------------------*/ |
| |
| static bitmap setjmp_crosses; |
| struct reg_info_t *reg_info_p; |
| |
| /* The number allocated elements of reg_info_p. */ |
| size_t reg_info_p_size; |
| |
| /* Compute register info: lifetime, bb, and number of defs and uses |
| for basic block BB. LIVE is a scratch bitvector used here. */ |
| |
| static void |
| regstat_bb_compute_ri (basic_block bb, bitmap live) |
| { |
| rtx_insn *insn; |
| df_ref def, use; |
| bitmap_iterator bi; |
| unsigned int regno; |
| |
| bitmap_copy (live, df_get_live_out (bb)); |
| |
| /* Process the regs live at the end of the block. Mark them as |
| not local to any one basic block. */ |
| EXECUTE_IF_SET_IN_BITMAP (live, 0, regno, bi) |
| REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; |
| |
| /* Process the artificial defs and uses at the bottom of the block |
| to begin processing. */ |
| FOR_EACH_ARTIFICIAL_DEF (def, bb->index) |
| if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0) |
| bitmap_clear_bit (live, DF_REF_REGNO (def)); |
| |
| FOR_EACH_ARTIFICIAL_USE (use, bb->index) |
| if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0) |
| { |
| regno = DF_REF_REGNO (use); |
| bitmap_set_bit (live, regno); |
| } |
| |
| FOR_BB_INSNS_REVERSE (bb, insn) |
| { |
| struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn); |
| bitmap_iterator bi; |
| rtx link; |
| |
| if (!NONDEBUG_INSN_P (insn)) |
| continue; |
| |
| link = REG_NOTES (insn); |
| while (link) |
| { |
| if (REG_NOTE_KIND (link) == REG_DEAD) |
| REG_N_DEATHS (REGNO (XEXP (link, 0)))++; |
| link = XEXP (link, 1); |
| } |
| |
| /* Process the defs. */ |
| if (CALL_P (insn)) |
| { |
| bool set_jump = (find_reg_note (insn, REG_SETJMP, NULL) != NULL); |
| EXECUTE_IF_SET_IN_BITMAP (live, 0, regno, bi) |
| { |
| REG_N_CALLS_CROSSED (regno)++; |
| |
| /* We have a problem with any pseudoreg that lives |
| across the setjmp. ANSI says that if a user variable |
| does not change in value between the setjmp and the |
| longjmp, then the longjmp preserves it. This |
| includes longjmp from a place where the pseudo |
| appears dead. (In principle, the value still exists |
| if it is in scope.) If the pseudo goes in a hard |
| reg, some other value may occupy that hard reg where |
| this pseudo is dead, thus clobbering the pseudo. |
| Conclusion: such a pseudo must not go in a hard |
| reg. */ |
| if (set_jump) |
| bitmap_set_bit (setjmp_crosses, regno); |
| } |
| } |
| |
| /* All of the defs except the return value are some sort of |
| clobber. This code is for the return. */ |
| FOR_EACH_INSN_INFO_DEF (def, insn_info) |
| { |
| if ((!CALL_P (insn)) |
| || (!(DF_REF_FLAGS (def) |
| & (DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER)))) |
| { |
| unsigned int dregno = DF_REF_REGNO (def); |
| |
| /* Kill this register if it is not a subreg store or |
| conditional store. |
| ??? This means that any partial store is live from |
| the last use in a basic block to the start of this |
| basic block. */ |
| if (!(DF_REF_FLAGS (def) |
| & (DF_REF_PARTIAL | DF_REF_CONDITIONAL))) |
| bitmap_clear_bit (live, dregno); |
| |
| if (dregno >= FIRST_PSEUDO_REGISTER) |
| { |
| REG_FREQ (dregno) += REG_FREQ_FROM_BB (bb); |
| REG_FREQ (dregno) = |
| MIN (REG_FREQ (dregno), REG_FREQ_MAX); |
| |
| if (REG_BASIC_BLOCK (dregno) == REG_BLOCK_UNKNOWN) |
| REG_BASIC_BLOCK (dregno) = bb->index; |
| else if (REG_BASIC_BLOCK (dregno) != bb->index) |
| REG_BASIC_BLOCK (dregno) = REG_BLOCK_GLOBAL; |
| } |
| } |
| } |
| |
| FOR_EACH_INSN_INFO_USE (use, insn_info) |
| { |
| unsigned int uregno = DF_REF_REGNO (use); |
| |
| if (uregno >= FIRST_PSEUDO_REGISTER) |
| { |
| REG_FREQ (uregno) += REG_FREQ_FROM_BB (bb); |
| REG_FREQ (uregno) = |
| MIN (REG_FREQ (uregno), REG_FREQ_MAX); |
| |
| if (REG_BASIC_BLOCK (uregno) == REG_BLOCK_UNKNOWN) |
| REG_BASIC_BLOCK (uregno) = bb->index; |
| else if (REG_BASIC_BLOCK (uregno) != bb->index) |
| REG_BASIC_BLOCK (uregno) = REG_BLOCK_GLOBAL; |
| } |
| } |
| } |
| } |
| |
| |
| /* Compute register info: lifetime, bb, and number of defs and uses. */ |
| void |
| regstat_compute_ri (void) |
| { |
| basic_block bb; |
| bitmap live = BITMAP_ALLOC (&df_bitmap_obstack); |
| unsigned int regno; |
| bitmap_iterator bi; |
| |
| /* Initialize everything. */ |
| |
| gcc_assert (!reg_info_p); |
| |
| timevar_push (TV_REG_STATS); |
| setjmp_crosses = BITMAP_ALLOC (&df_bitmap_obstack); |
| max_regno = max_reg_num (); |
| reg_info_p_size = max_regno; |
| reg_info_p = XCNEWVEC (struct reg_info_t, max_regno); |
| |
| FOR_EACH_BB_FN (bb, cfun) |
| { |
| regstat_bb_compute_ri (bb, live); |
| } |
| |
| BITMAP_FREE (live); |
| |
| /* See the setjmp comment in regstat_bb_compute_ri. */ |
| EXECUTE_IF_SET_IN_BITMAP (setjmp_crosses, FIRST_PSEUDO_REGISTER, regno, bi) |
| { |
| REG_BASIC_BLOCK (regno) = REG_BLOCK_UNKNOWN; |
| } |
| |
| timevar_pop (TV_REG_STATS); |
| } |
| |
| |
| /* Free all storage associated with the problem. */ |
| |
| void |
| regstat_free_ri (void) |
| { |
| gcc_assert (reg_info_p); |
| reg_info_p_size = 0; |
| free (reg_info_p); |
| reg_info_p = NULL; |
| |
| BITMAP_FREE (setjmp_crosses); |
| } |
| |
| |
| /* Return a bitmap containing the set of registers that cross a setjmp. |
| The client should not change or delete this bitmap. */ |
| |
| bitmap |
| regstat_get_setjmp_crosses (void) |
| { |
| return setjmp_crosses; |
| } |
| |
| /*---------------------------------------------------------------------------- |
| Process REG_N_CALLS_CROSSED. |
| |
| This is used by sched_deps. A good implementation of sched-deps |
| would really process the blocks directly rather than going through |
| lists of insns. If it did this, it could use the exact regs that |
| cross an individual call rather than using this info that merges |
| the info for all calls. |
| |
| ----------------------------------------------------------------------------*/ |
| |
| |
| |
| /* Compute calls crossed for BB. Live is a scratch bitvector. */ |
| |
| static void |
| regstat_bb_compute_calls_crossed (unsigned int bb_index, bitmap live) |
| { |
| basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index); |
| rtx_insn *insn; |
| df_ref def, use; |
| |
| bitmap_copy (live, df_get_live_out (bb)); |
| |
| /* Process the artificial defs and uses at the bottom of the block |
| to begin processing. */ |
| FOR_EACH_ARTIFICIAL_DEF (def, bb_index) |
| if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0) |
| bitmap_clear_bit (live, DF_REF_REGNO (def)); |
| |
| FOR_EACH_ARTIFICIAL_USE (use, bb_index) |
| if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0) |
| bitmap_set_bit (live, DF_REF_REGNO (use)); |
| |
| FOR_BB_INSNS_REVERSE (bb, insn) |
| { |
| struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn); |
| unsigned int regno; |
| |
| if (!NONDEBUG_INSN_P (insn)) |
| continue; |
| |
| /* Process the defs. */ |
| if (CALL_P (insn)) |
| { |
| bitmap_iterator bi; |
| EXECUTE_IF_SET_IN_BITMAP (live, 0, regno, bi) |
| { |
| REG_N_CALLS_CROSSED (regno)++; |
| } |
| } |
| |
| /* All of the defs except the return value are some sort of |
| clobber. This code is for the return. */ |
| FOR_EACH_INSN_INFO_DEF (def, insn_info) |
| { |
| if ((!CALL_P (insn)) |
| || (!(DF_REF_FLAGS (def) & (DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER)))) |
| { |
| /* Kill this register if it is not a subreg store or conditional store. */ |
| if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL))) |
| bitmap_clear_bit (live, DF_REF_REGNO (def)); |
| } |
| } |
| |
| FOR_EACH_INSN_INFO_USE (use, insn_info) |
| bitmap_set_bit (live, DF_REF_REGNO (use)); |
| } |
| } |
| |
| |
| /* Compute register info: lifetime, bb, and number of defs and uses. */ |
| void |
| regstat_compute_calls_crossed (void) |
| { |
| basic_block bb; |
| bitmap live = BITMAP_ALLOC (&df_bitmap_obstack); |
| |
| /* Initialize everything. */ |
| gcc_assert (!reg_info_p); |
| |
| timevar_push (TV_REG_STATS); |
| max_regno = max_reg_num (); |
| reg_info_p_size = max_regno; |
| reg_info_p = XCNEWVEC (struct reg_info_t, max_regno); |
| |
| FOR_EACH_BB_FN (bb, cfun) |
| { |
| regstat_bb_compute_calls_crossed (bb->index, live); |
| } |
| |
| BITMAP_FREE (live); |
| timevar_pop (TV_REG_STATS); |
| } |
| |
| |
| /* Free all storage associated with the problem. */ |
| |
| void |
| regstat_free_calls_crossed (void) |
| { |
| gcc_assert (reg_info_p); |
| reg_info_p_size = 0; |
| free (reg_info_p); |
| reg_info_p = NULL; |
| } |
| |
| /* Dump the register info to FILE. */ |
| |
| void |
| dump_reg_info (FILE *file) |
| { |
| unsigned int i, max = max_reg_num (); |
| if (reload_completed) |
| return; |
| |
| if (reg_info_p_size < max) |
| max = reg_info_p_size; |
| |
| fprintf (file, "%d registers.\n", max); |
| for (i = FIRST_PSEUDO_REGISTER; i < max; i++) |
| { |
| enum reg_class rclass, altclass; |
| |
| if (regstat_n_sets_and_refs) |
| fprintf (file, "\nRegister %d used %d times", |
| i, REG_N_REFS (i)); |
| else if (df) |
| fprintf (file, "\nRegister %d used %d times", |
| i, DF_REG_USE_COUNT (i) + DF_REG_DEF_COUNT (i)); |
| |
| if (REG_BASIC_BLOCK (i) >= NUM_FIXED_BLOCKS) |
| fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); |
| if (regstat_n_sets_and_refs) |
| fprintf (file, "; set %d time%s", REG_N_SETS (i), |
| (REG_N_SETS (i) == 1) ? "" : "s"); |
| else if (df) |
| fprintf (file, "; set %d time%s", DF_REG_DEF_COUNT (i), |
| (DF_REG_DEF_COUNT (i) == 1) ? "" : "s"); |
| if (regno_reg_rtx[i] != NULL && REG_USERVAR_P (regno_reg_rtx[i])) |
| fputs ("; user var", file); |
| if (REG_N_DEATHS (i) != 1) |
| fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); |
| if (REG_N_CALLS_CROSSED (i) == 1) |
| fputs ("; crosses 1 call", file); |
| else if (REG_N_CALLS_CROSSED (i)) |
| fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); |
| if (regno_reg_rtx[i] != NULL |
| && maybe_ne (PSEUDO_REGNO_BYTES (i), UNITS_PER_WORD)) |
| { |
| fprintf (file, "; "); |
| print_dec (PSEUDO_REGNO_BYTES (i), file, SIGNED); |
| fprintf (file, " bytes"); |
| } |
| |
| rclass = reg_preferred_class (i); |
| altclass = reg_alternate_class (i); |
| if (rclass != GENERAL_REGS || altclass != ALL_REGS) |
| { |
| if (altclass == ALL_REGS || rclass == ALL_REGS) |
| fprintf (file, "; pref %s", reg_class_names[(int) rclass]); |
| else if (altclass == NO_REGS) |
| fprintf (file, "; %s or none", reg_class_names[(int) rclass]); |
| else |
| fprintf (file, "; pref %s, else %s", |
| reg_class_names[(int) rclass], |
| reg_class_names[(int) altclass]); |
| } |
| |
| if (regno_reg_rtx[i] != NULL && REG_POINTER (regno_reg_rtx[i])) |
| fputs ("; pointer", file); |
| fputs (".\n", file); |
| } |
| } |
| |