diff options
| -rw-r--r-- | gcc/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/regclass.c | 8 |
2 files changed, 9 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index de821d4..1957893 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,8 @@ Tue Dec 14 12:07:29 MET 1999 Jan Hubicka <hubicka@freesoft.cz> + * regclass.c (record_reg_classes): Do not do the copying preferrencing + when source does not die. + * regclass.c (record_reg_classes): Handle INOUT operands propertly. 1999-12-14 Jakub Jelinek <jakub@redhat.com> diff --git a/gcc/regclass.c b/gcc/regclass.c index f48a7c2..a67d91e 100644 --- a/gcc/regclass.c +++ b/gcc/regclass.c @@ -1618,11 +1618,15 @@ record_reg_classes (n_alts, n_ops, ops, modes, subreg_changes_size, /* If this insn is a single set copying operand 1 to operand 0 and one is a pseudo with the other a hard reg that is in its - own register class, set the cost of that register class to -1. */ + own register class, set the cost of that register class to -1. + Do this only when source dies to avoid stressing of register + allocator by preferrencing two coliding registers into single + place. */ if ((set = single_set (insn)) != 0 && ops[0] == SET_DEST (set) && ops[1] == SET_SRC (set) - && GET_CODE (ops[0]) == REG && GET_CODE (ops[1]) == REG) + && GET_CODE (ops[0]) == REG && GET_CODE (ops[1]) == REG + && find_regno_note (insn, REG_DEAD, REGNO (ops[1]))) for (i = 0; i <= 1; i++) if (REGNO (ops[i]) >= FIRST_PSEUDO_REGISTER) { |