After the previous changes, several callers are left with code like:
if (HARD_REGISTER_P (x))
bitmap_foo_range (x, REGNO (x), REG_NREGS (x));
else
bitmap_foo (x, REGNO (x));
These might as well now be:
if (REG_NREGS (x) > 1)
bitmap_foo_range (x, REGNO (x), REG_NREGS (x));
else
bitmap_foo (x, REGNO (x));
since REG_NREGS is as cheap to test, and since single-register hard REGs
are the common case. But if separating out the cases is a win -- and it
seems to be, very slightly -- then it would be better to add the shortcut
to the range functions themselves.
gcc/
* bitmap.c (bitmap_set_range): Handle count==1 specially.
(bitmap_clear_range): Likewise.
* cfgcleanup.c (mark_effect): Use bitmap_clear_range and
bitmap_set_range unconditionally.
* df-problems.c (df_simulate_one_insn_forwards): Likewise.
* df-scan.c (df_mark_reg): Likewise.
* haifa-sched.c (setup_ref_regs): Likewise.
* sched-rgn.c (update_live_1): Likewise.