static bool copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd) { bool anything_changed = false; rtx insn; for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) { int n_ops, i, alt, predicated; bool is_asm, any_replacements; rtx set; bool replaced[MAX_RECOG_OPERANDS]; bool changed = false; struct kill_set_value_data ksvd; if (!NONDEBUG_INSN_P (insn)) { if (DEBUG_INSN_P (insn)) { rtx loc = INSN_VAR_LOCATION_LOC (insn); if (!VAR_LOC_UNKNOWN_P (loc)) replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn), ALL_REGS, GET_MODE (loc), ADDR_SPACE_GENERIC, insn, vd); } 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; } /* Apply changes to earlier DEBUG_INSNs if possible. */ if (vd->n_debug_insn_changes) note_uses (&PATTERN (insn), cprop_find_used_regs, vd); /* 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_rtx; /* 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; /* And likewise, if we are narrowing on big endian the transformation is also invalid. */ if (hard_regno_nregs[regno][mode] < hard_regno_nregs[regno][vd->e[regno].mode] && (GET_MODE_SIZE (vd->e[regno].mode) > UNITS_PER_WORD ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN)) 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_rtx = find_oldest_value_reg (REGNO_REG_CLASS (regno), src, vd); if (new_rtx && validate_change (insn, &SET_SRC (set), new_rtx, 0)) { if (dump_file) fprintf (dump_file, "insn %u: replaced reg %u with %u\n", INSN_UID (insn), regno, REGNO (new_rtx)); changed = true; goto did_replacement; } /* We need to re-extract as validate_change clobbers recog_data. */ extract_insn (insn); if (! constrain_operands (1)) fatal_insn_not_found (insn); preprocess_constraints (); } /* 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_rtx = maybe_mode_change (vd->e[i].mode, vd->e[regno].mode, mode, i, regno); if (new_rtx != NULL_RTX) { if (validate_change (insn, &SET_SRC (set), new_rtx, 0)) { ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src); REG_ATTRS (new_rtx) = REG_ATTRS (src); REG_POINTER (new_rtx) = REG_POINTER (src); if (dump_file) fprintf (dump_file, "insn %u: replaced reg %u with %u\n", INSN_UID (insn), regno, REGNO (new_rtx)); changed = true; goto did_replacement; } /* We need to re-extract as validate_change clobbers recog_data. */ extract_insn (insn); if (! constrain_operands (1)) fatal_insn_not_found (insn); preprocess_constraints (); } } } no_move_special_case: any_replacements = false; /* 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++) { replaced[i] = 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[i] = replace_oldest_value_addr (recog_data.operand_loc[i], recog_op_alt[i][alt].cl, VOIDmode, ADDR_SPACE_GENERIC, insn, vd); else if (REG_P (recog_data.operand[i])) replaced[i] = 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[i] = replace_oldest_value_mem (recog_data.operand[i], insn, vd); } else if (MEM_P (recog_data.operand[i])) replaced[i] = replace_oldest_value_mem (recog_data.operand[i], insn, vd); /* If we performed any replacement, update match_dups. */ if (replaced[i]) { int j; rtx new_rtx; new_rtx = *recog_data.operand_loc[i]; recog_data.operand[i] = new_rtx; for (j = 0; j < recog_data.n_dups; j++) if (recog_data.dup_num[j] == i) validate_unshare_change (insn, recog_data.dup_loc[j], new_rtx, 1); any_replacements = true; } } if (any_replacements) { if (! apply_change_group ()) { for (i = 0; i < n_ops; i++) if (replaced[i]) { rtx old = *recog_data.operand_loc[i]; recog_data.operand[i] = old; } if (dump_file) fprintf (dump_file, "insn %u: reg replacements not verified\n", INSN_UID (insn)); } else changed = true; } did_replacement: if (changed) { anything_changed = true; /* If something changed, perhaps further changes to earlier DEBUG_INSNs can be applied. */ if (vd->n_debug_insn_changes) note_uses (&PATTERN (insn), cprop_find_used_regs, vd); } ksvd.vd = vd; ksvd.ignore_set_reg = NULL_RTX; /* Clobber call-clobbered registers. */ if (CALL_P (insn)) { unsigned int set_regno = INVALID_REGNUM; unsigned int set_nregs = 0; unsigned int regno; rtx exp; hard_reg_set_iterator hrsi; for (exp = CALL_INSN_FUNCTION_USAGE (insn); exp; exp = XEXP (exp, 1)) { rtx x = XEXP (exp, 0); if (GET_CODE (x) == SET) { rtx dest = SET_DEST (x); kill_value (dest, vd); set_value_regno (REGNO (dest), GET_MODE (dest), vd); copy_value (dest, SET_SRC (x), vd); ksvd.ignore_set_reg = dest; set_regno = REGNO (dest); set_nregs = hard_regno_nregs[set_regno][GET_MODE (dest)]; break; } } EXECUTE_IF_SET_IN_HARD_REG_SET (regs_invalidated_by_call, 0, regno, hrsi) if (regno < set_regno || regno >= set_regno + set_nregs) kill_value_regno (regno, 1, vd); /* If SET was seen in CALL_INSN_FUNCTION_USAGE, and SET_SRC of the SET isn't in regs_invalidated_by_call hard reg set, but instead among CLOBBERs on the CALL_INSN, we could wrongly assume the value in it is still live. */ if (ksvd.ignore_set_reg) note_stores (PATTERN (insn), kill_clobbered_value, vd); } /* Notice stores. */ note_stores (PATTERN (insn), kill_set_value, &ksvd); /* 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 anything_changed; }
static int reload_cse_simplify_set (rtx set, rtx insn) { int did_change = 0; int dreg; rtx src; enum reg_class dclass; int old_cost; cselib_val *val; struct elt_loc_list *l; #ifdef LOAD_EXTEND_OP enum rtx_code extend_op = UNKNOWN; #endif bool speed = optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn)); dreg = true_regnum (SET_DEST (set)); if (dreg < 0) return 0; src = SET_SRC (set); if (side_effects_p (src) || true_regnum (src) >= 0) return 0; dclass = REGNO_REG_CLASS (dreg); #ifdef LOAD_EXTEND_OP /* When replacing a memory with a register, we need to honor assumptions that combine made wrt the contents of sign bits. We'll do this by generating an extend instruction instead of a reg->reg copy. Thus the destination must be a register that we can widen. */ if (MEM_P (src) && GET_MODE_BITSIZE (GET_MODE (src)) < BITS_PER_WORD && (extend_op = LOAD_EXTEND_OP (GET_MODE (src))) != UNKNOWN && !REG_P (SET_DEST (set))) return 0; #endif val = cselib_lookup (src, GET_MODE (SET_DEST (set)), 0); if (! val) return 0; /* If memory loads are cheaper than register copies, don't change them. */ if (MEM_P (src)) old_cost = MEMORY_MOVE_COST (GET_MODE (src), dclass, 1); else if (REG_P (src)) old_cost = REGISTER_MOVE_COST (GET_MODE (src), REGNO_REG_CLASS (REGNO (src)), dclass); else old_cost = rtx_cost (src, SET, speed); for (l = val->locs; l; l = l->next) { rtx this_rtx = l->loc; int this_cost; if (CONSTANT_P (this_rtx) && ! references_value_p (this_rtx, 0)) { #ifdef LOAD_EXTEND_OP if (extend_op != UNKNOWN) { HOST_WIDE_INT this_val; /* ??? I'm lazy and don't wish to handle CONST_DOUBLE. Other constants, such as SYMBOL_REF, cannot be extended. */ if (GET_CODE (this_rtx) != CONST_INT) continue; this_val = INTVAL (this_rtx); switch (extend_op) { case ZERO_EXTEND: this_val &= GET_MODE_MASK (GET_MODE (src)); break; case SIGN_EXTEND: /* ??? In theory we're already extended. */ if (this_val == trunc_int_for_mode (this_val, GET_MODE (src))) break; default: gcc_unreachable (); } this_rtx = GEN_INT (this_val); } #endif this_cost = rtx_cost (this_rtx, SET, speed); } else if (REG_P (this_rtx)) { #ifdef LOAD_EXTEND_OP if (extend_op != UNKNOWN) { this_rtx = gen_rtx_fmt_e (extend_op, word_mode, this_rtx); this_cost = rtx_cost (this_rtx, SET, speed); } else #endif this_cost = REGISTER_MOVE_COST (GET_MODE (this_rtx), REGNO_REG_CLASS (REGNO (this_rtx)), dclass); } else continue; /* If equal costs, prefer registers over anything else. That tends to lead to smaller instructions on some machines. */ if (this_cost < old_cost || (this_cost == old_cost && REG_P (this_rtx) && !REG_P (SET_SRC (set)))) { #ifdef LOAD_EXTEND_OP if (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) < BITS_PER_WORD && extend_op != UNKNOWN #ifdef CANNOT_CHANGE_MODE_CLASS && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SET_DEST (set)), word_mode, REGNO_REG_CLASS (REGNO (SET_DEST (set)))) #endif ) { rtx wide_dest = gen_rtx_REG (word_mode, REGNO (SET_DEST (set))); ORIGINAL_REGNO (wide_dest) = ORIGINAL_REGNO (SET_DEST (set)); validate_change (insn, &SET_DEST (set), wide_dest, 1); } #endif validate_unshare_change (insn, &SET_SRC (set), this_rtx, 1); old_cost = this_cost, did_change = 1; } } return did_change; }