- bool changed = false;
- rtx insn;
-
- for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
- {
- int n_ops, i, alt, predicated;
- bool is_asm;
- rtx set;
-
- if (! INSN_P (insn))
- {
- if (insn == BB_END (bb))
- break;
- else
- continue;
- }
-
- set = single_set (insn);
- extract_insn (insn);
- if (! constrain_operands (1))
- fatal_insn_not_found (insn);
- preprocess_constraints ();
- alt = which_alternative;
- n_ops = recog_data.n_operands;
- is_asm = asm_noperands (PATTERN (insn)) >= 0;
-
- /* Simplify the code below by rewriting things to reflect
- matching constraints. Also promote OP_OUT to OP_INOUT
- in predicated instructions. */
-
- predicated = GET_CODE (PATTERN (insn)) == COND_EXEC;
- for (i = 0; i < n_ops; ++i)
- {
- int matches = recog_op_alt[i][alt].matches;
- if (matches >= 0)
- recog_op_alt[i][alt].cl = recog_op_alt[matches][alt].cl;
- if (matches >= 0 || recog_op_alt[i][alt].matched >= 0
- || (predicated && recog_data.operand_type[i] == OP_OUT))
- recog_data.operand_type[i] = OP_INOUT;
- }
-
- /* For each earlyclobber operand, zap the value data. */
- for (i = 0; i < n_ops; i++)
- if (recog_op_alt[i][alt].earlyclobber)
- kill_value (recog_data.operand[i], vd);
-
- /* Within asms, a clobber cannot overlap inputs or outputs.
- I wouldn't think this were true for regular insns, but
- scan_rtx treats them like that... */
- note_stores (PATTERN (insn), kill_clobbered_value, vd);
-
- /* Kill all auto-incremented values. */
- /* ??? REG_INC is useless, since stack pushes aren't done that way. */
- for_each_rtx (&PATTERN (insn), kill_autoinc_value, vd);
-
- /* Kill all early-clobbered operands. */
- for (i = 0; i < n_ops; i++)
- if (recog_op_alt[i][alt].earlyclobber)
- kill_value (recog_data.operand[i], vd);
-
- /* Special-case plain move instructions, since we may well
- be able to do the move from a different register class. */
- if (set && REG_P (SET_SRC (set)))
- {
- rtx src = SET_SRC (set);
- unsigned int regno = REGNO (src);
- enum machine_mode mode = GET_MODE (src);
- unsigned int i;
- rtx new;
-
- /* If we are accessing SRC in some mode other that what we
- set it in, make sure that the replacement is valid. */
- if (mode != vd->e[regno].mode)
- {
- if (hard_regno_nregs[regno][mode]
- > hard_regno_nregs[regno][vd->e[regno].mode])
- goto no_move_special_case;
- }
-
- /* If the destination is also a register, try to find a source
- register in the same class. */
- if (REG_P (SET_DEST (set)))
- {
- new = find_oldest_value_reg (REGNO_REG_CLASS (regno), src, vd);
- if (new && validate_change (insn, &SET_SRC (set), new, 0))
- {
- if (dump_file)
- fprintf (dump_file,
- "insn %u: replaced reg %u with %u\n",
- INSN_UID (insn), regno, REGNO (new));
- changed = true;
- goto did_replacement;
- }
- }
-
- /* Otherwise, try all valid registers and see if its valid. */
- for (i = vd->e[regno].oldest_regno; i != regno;
- i = vd->e[i].next_regno)
- {
- new = maybe_mode_change (vd->e[i].mode, vd->e[regno].mode,
- mode, i, regno);
- if (new != NULL_RTX)
- {
- if (validate_change (insn, &SET_SRC (set), new, 0))
- {
- ORIGINAL_REGNO (new) = ORIGINAL_REGNO (src);
- REG_ATTRS (new) = REG_ATTRS (src);
- if (dump_file)
- fprintf (dump_file,
- "insn %u: replaced reg %u with %u\n",
- INSN_UID (insn), regno, REGNO (new));
- changed = true;
- goto did_replacement;
- }
- }
- }
- }
- no_move_special_case:
-
- /* For each input operand, replace a hard register with the
- eldest live copy that's in an appropriate register class. */
- for (i = 0; i < n_ops; i++)
- {
- bool replaced = false;
-
- /* Don't scan match_operand here, since we've no reg class
- information to pass down. Any operands that we could
- substitute in will be represented elsewhere. */
- if (recog_data.constraints[i][0] == '\0')
- continue;
-
- /* Don't replace in asms intentionally referencing hard regs. */
- if (is_asm && REG_P (recog_data.operand[i])
- && (REGNO (recog_data.operand[i])
- == ORIGINAL_REGNO (recog_data.operand[i])))
- continue;
-
- if (recog_data.operand_type[i] == OP_IN)
- {
- if (recog_op_alt[i][alt].is_address)
- replaced
- = replace_oldest_value_addr (recog_data.operand_loc[i],
- recog_op_alt[i][alt].cl,
- VOIDmode, insn, vd);
- else if (REG_P (recog_data.operand[i]))
- replaced
- = replace_oldest_value_reg (recog_data.operand_loc[i],
- recog_op_alt[i][alt].cl,
- insn, vd);
- else if (MEM_P (recog_data.operand[i]))
- replaced = replace_oldest_value_mem (recog_data.operand[i],
- insn, vd);
- }
- else if (MEM_P (recog_data.operand[i]))
- replaced = replace_oldest_value_mem (recog_data.operand[i],
- insn, vd);
-
- /* If we performed any replacement, update match_dups. */
- if (replaced)
- {
- int j;
- rtx new;
-
- changed = true;
-
- new = *recog_data.operand_loc[i];
- recog_data.operand[i] = new;
- for (j = 0; j < recog_data.n_dups; j++)
- if (recog_data.dup_num[j] == i)
- *recog_data.dup_loc[j] = new;
- }
- }
-
- did_replacement:
- /* Clobber call-clobbered registers. */
- if (CALL_P (insn))
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
- kill_value_regno (i, 1, vd);
-
- /* Notice stores. */
- note_stores (PATTERN (insn), kill_set_value, vd);
-
- /* Notice copies. */
- if (set && REG_P (SET_DEST (set)) && REG_P (SET_SRC (set)))
- copy_value (SET_DEST (set), SET_SRC (set), vd);
-
- if (insn == BB_END (bb))
- break;
- }
-
- return changed;
-}
-
-/* Main entry point for the forward copy propagation optimization. */
-
-void
-copyprop_hardreg_forward (void)
-{
- struct value_data *all_vd;
- bool need_refresh;
- basic_block bb, bbp = 0;
-
- need_refresh = false;
-
- all_vd = xmalloc (sizeof (struct value_data) * last_basic_block);
-
- FOR_EACH_BB (bb)
- {
- /* If a block has a single predecessor, that we've already
- processed, begin with the value data that was live at
- the end of the predecessor block. */
- /* ??? Ought to use more intelligent queuing of blocks. */
- if (EDGE_COUNT (bb->preds) == 1)
- for (bbp = bb; bbp && bbp != EDGE_PRED (bb, 0)->src; bbp = bbp->prev_bb);
- if (EDGE_COUNT (bb->preds) == 1
- && ! (EDGE_PRED (bb, 0)->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
- && EDGE_PRED (bb, 0)->src != ENTRY_BLOCK_PTR
- && bbp)
- all_vd[bb->index] = all_vd[EDGE_PRED (bb, 0)->src->index];
- else
- init_value_data (all_vd + bb->index);
-
- if (copyprop_hardreg_forward_1 (bb, all_vd + bb->index))
- need_refresh = true;
- }
-
- if (need_refresh)
- {
- if (dump_file)
- fputs ("\n\n", dump_file);
-
- /* ??? Irritatingly, delete_noop_moves does not take a set of blocks
- to scan, so we have to do a life update with no initial set of
- blocks Just In Case. */
- delete_noop_moves ();
- update_life_info (NULL, UPDATE_LIFE_GLOBAL_RM_NOTES,
- PROP_DEATH_NOTES
- | PROP_SCAN_DEAD_CODE
- | PROP_KILL_DEAD_CODE);
- }
-
- free (all_vd);
-}
-
-/* Dump the value chain data to stderr. */
-
-void
-debug_value_data (struct value_data *vd)
-{
- HARD_REG_SET set;
- unsigned int i, j;
-
- CLEAR_HARD_REG_SET (set);
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
- if (vd->e[i].oldest_regno == i)
- {
- if (vd->e[i].mode == VOIDmode)
- {
- if (vd->e[i].next_regno != INVALID_REGNUM)
- fprintf (stderr, "[%u] Bad next_regno for empty chain (%u)\n",
- i, vd->e[i].next_regno);
- continue;
- }
-
- SET_HARD_REG_BIT (set, i);
- fprintf (stderr, "[%u %s] ", i, GET_MODE_NAME (vd->e[i].mode));
-
- for (j = vd->e[i].next_regno;
- j != INVALID_REGNUM;
- j = vd->e[j].next_regno)
- {
- if (TEST_HARD_REG_BIT (set, j))
- {
- fprintf (stderr, "[%u] Loop in regno chain\n", j);
- return;
- }
-
- if (vd->e[j].oldest_regno != i)
- {
- fprintf (stderr, "[%u] Bad oldest_regno (%u)\n",
- j, vd->e[j].oldest_regno);
- return;
- }
- SET_HARD_REG_BIT (set, j);
- fprintf (stderr, "[%u %s] ", j, GET_MODE_NAME (vd->e[j].mode));
- }
- fputc ('\n', stderr);
- }
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
- if (! TEST_HARD_REG_BIT (set, i)
- && (vd->e[i].mode != VOIDmode
- || vd->e[i].oldest_regno != i
- || vd->e[i].next_regno != INVALID_REGNUM))
- fprintf (stderr, "[%u] Non-empty reg in chain (%s %u %i)\n",
- i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno,
- vd->e[i].next_regno);
-}
-
-#ifdef ENABLE_CHECKING
-static void
-validate_value_data (struct value_data *vd)
-{
- HARD_REG_SET set;
- unsigned int i, j;
-
- CLEAR_HARD_REG_SET (set);
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
- if (vd->e[i].oldest_regno == i)
- {
- if (vd->e[i].mode == VOIDmode)
- {
- if (vd->e[i].next_regno != INVALID_REGNUM)
- internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
- i, vd->e[i].next_regno);
- continue;
- }
-
- SET_HARD_REG_BIT (set, i);
-
- for (j = vd->e[i].next_regno;
- j != INVALID_REGNUM;
- j = vd->e[j].next_regno)
- {
- if (TEST_HARD_REG_BIT (set, j))
- internal_error ("validate_value_data: Loop in regno chain (%u)",
- j);
- if (vd->e[j].oldest_regno != i)
- internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
- j, vd->e[j].oldest_regno);
-
- SET_HARD_REG_BIT (set, j);
- }
- }
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
- if (! TEST_HARD_REG_BIT (set, i)
- && (vd->e[i].mode != VOIDmode
- || vd->e[i].oldest_regno != i
- || vd->e[i].next_regno != INVALID_REGNUM))
- internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
- i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno,
- vd->e[i].next_regno);
-}
-#endif