On 2023/11/13 9:11, juzhe.zh...@rivai.ai wrote:
Ah, nice! How configurable are the bit ranges?
I think Lehua's patch is configurable for bit ranges.
Since his patch allow target flexible tracking subreg livenesss
according to REGMODE_NATURAL_SIZE
+/* Return true if REGNO is a pseudo and MODE is a multil regs size. */
+bool
+need_track_subreg (int regno, machine_mode reg_mode)
+{
+ poly_int64 total_size = GET_MODE_SIZE (reg_mode);
+ poly_int64 natural_size = REGMODE_NATURAL_SIZE (reg_mode);
+ return maybe_gt (total_size, natural_size)
+ && multiple_p (total_size, natural_size)
+ && regno >= FIRST_PSEUDO_REGISTER;
+}
It depends on how targets configure REGMODE_NATURAL_SIZE target hook.
If we return QImode size, his patch is enable tracking bit ranges 7 bits
subreg.
Yes, the current subreg_ranges class provides
remove_range/add_range/remove_ranges/add_ranges interfaces to modify
ranges. Each subreg_range contains start and end fields representing the
range [start, end). For live_subreg problem, the value returned by
REGMODE_NATURAL_SIZE is used as the unit, for bit track like Jeff's
side, it can be used bit as the unit.
--
Best,
Lehua (RiVAI)
lehua.d...@rivai.ai
