diff options
Diffstat (limited to 'gcc/local-alloc.c')
| -rw-r--r-- | gcc/local-alloc.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/gcc/local-alloc.c b/gcc/local-alloc.c index 4466169..677801e 100644 --- a/gcc/local-alloc.c +++ b/gcc/local-alloc.c @@ -1048,6 +1048,22 @@ update_equiv_regs () note = find_reg_note (insn, REG_EQUAL, NULL_RTX); +#ifdef DONT_RECORD_EQUIVALENCE + /* Allow the target to reject promotions of some REG_EQUAL notes to + REG_EQUIV notes. + + In some cases this can improve register allocation if the existence + of the REG_EQUIV note is likely to increase the lifetime of a register + that is likely to be spilled. + + It may also be necessary if the target can't handle certain constant + expressions appearing randomly in insns, but for whatever reason + those expressions must be considered legitimate constant expressions + to prevent them from being forced into memory. */ + if (note && DONT_RECORD_EQUIVALENCE (note)) + note = NULL; +#endif + /* Record this insn as initializing this register. */ reg_equiv_init_insn[regno] = insn; |