diff options
Diffstat (limited to 'gcc/lra-constraints.c')
| -rw-r--r-- | gcc/lra-constraints.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index cfc3d7eaaee..aac50876d21 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -1747,12 +1747,27 @@ process_alt_operands (int only_alternative) [GET_MODE (*curr_id->operand_loc[m])]); } - /* We prefer no matching alternatives because - it gives more freedom in RA. */ - if (operand_reg[nop] == NULL_RTX - || (find_regno_note (curr_insn, REG_DEAD, - REGNO (operand_reg[nop])) - == NULL_RTX)) + /* Prefer matching earlyclobber alternative as + it results in less hard regs required for + the insn than a non-matching earlyclobber + alternative. */ + if (curr_static_id->operand[m].early_clobber) + { + if (lra_dump_file != NULL) + fprintf + (lra_dump_file, + " %d Matching earlyclobber alt:" + " reject--\n", + nop); + reject--; + } + /* Otherwise we prefer no matching + alternatives because it gives more freedom + in RA. */ + else if (operand_reg[nop] == NULL_RTX + || (find_regno_note (curr_insn, REG_DEAD, + REGNO (operand_reg[nop])) + == NULL_RTX)) { if (lra_dump_file != NULL) fprintf @@ -2143,7 +2158,7 @@ process_alt_operands (int only_alternative) } /* If the operand is dying, has a matching constraint, and satisfies constraints of the matched operand - which failed to satisfy the own constraints, probably + which failed to satisfy the own constraints, most probably the reload for this operand will be gone. */ if (this_alternative_matches >= 0 && !curr_alt_win[this_alternative_matches] |