On Thu, May 17, 2018 at 3:04 PM, Richard Biener wrote: > On Tue, May 15, 2018 at 5:44 PM Bin.Cheng wrote: > >> On Fri, May 11, 2018 at 1:53 PM, Richard Biener >> wrote: >> > On Fri, May 4, 2018 at 6:23 PM, Bin Cheng wrote: >> >> Hi, >> >> Following Jeff's suggestion, I am now using existing tree-ssa-live.c > and >> >> tree-ssa-coalesce.c to compute register pressure, rather than inventing >> >> another live range solver. >> >> >> >> The major change is to record region's basic blocks in var_map and use > that >> >> information in computation, rather than FOR_EACH_BB_FN. For now only > loop >> >> and function type regions are supported. The default one is function > type >> >> region which is used in out-of-ssa. Loop type region will be used in > next >> >> patch to compute information for a loop. >> >> >> >> Bootstrap and test on x86_64 and AArch64 ongoing. Any comments? >> > >> > I believe your changes to create_outofssa_var_map should be done > differently >> > by simply only calling it from the coalescing context and passing in the >> > var_map rather than initializing it therein and returning it. >> > >> > This also means the coalesce_vars_p flag in the var_map structure looks >> > somewhat out-of-place. That is, it looks you could do with many less >> > changes if you refactored what calls what slightly? For example >> > the extra arg to gimple_can_coalesce_p looks unneeded. >> > >> > Just as a note I do have a CFG helper pending that computes RPO order >> > for SEME regions (attached). loops are SEME regions, so your RTYPE_SESE >> > is somewhat odd - I guess RTYPE_LOOP exists only because of the >> > convenience of passing in a loop * to the "constructor". I'd rather >> > drop this region_type thing and always assume a SEME region - at least >> > I didn't see anything in the patch that depends on any of the forms >> > apart from the initial BB gathering. > >> Hi Richard, > >> Thanks for reviewing. I refactored tree-ssa-live.c and >> tree-ssa-coalesce.c following your comments. >> Basically I did following changes: >> 1) Remove region_type and only support loop region live range computation. >> Also I added one boolean field in var_map indicating whether we >> are computing >> loop region live range or out-of-ssa. >> 2) Refactored create_outofssa_var_map into > create_coalesce_list_for_region and >> populate_coalesce_list_for_outofssa. Actually the original >> function name doesn't >> quite make sense because it has nothing to do with var_map. >> 3) Hoist init_var_map up in call stack. Now it's called by caller >> (out-of-ssa or live range) >> and the returned var_map is passed to coalesce_* stuff. >> 4) Move global functions to tree-outof-ssa.c and make them static. >> 5) Save/restore flag_tree_coalesce_vars in order to avoid updating >> checks on the flag. > >> So how is this one? Patch attached. > > A lot better. Few things I noticed: > > + map->bmp_bbs = BITMAP_ALLOC (NULL); > > use a bitmap_head member and bitmap_initialize (). > > + map->vec_bbs = new vec (); > > use a vec<> member and map->vec_bbs = vNULL; > > Both changes remove an unnecessary indirection. > > + map->outofssa_p = true; > + basic_block bb; > + FOR_EACH_BB_FN (bb, cfun) > + { > + bitmap_set_bit (map->bmp_bbs, bb->index); > + map->vec_bbs->safe_push (bb); > + } > > I think you can avoid populating the bitmap and return > true unconditionally for outofssa_p in the contains function? > Ah, you already do - so why populate the bitmap? > > +/* Return TRUE if region of the MAP contains basic block BB. */ > + > +inline bool > +region_contains_p (var_map map, basic_block bb) > +{ > + if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) > + || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) > + return false; > + > + if (map->outofssa_p) > + return true; > + > + return bitmap_bit_p (map->bmp_bbs, bb->index); > > the entry/exit block check should be conditional in map->outofssa_p > but I think we should never get the function called with those args > so we can as well use a gcc_checking_assert ()? > > I think as followup we should try to get a BB order that > is more suited for the dataflow problem. Btw, I was > thinking about adding anoter "visited" BB flag that is guaranteed to > be unset and free to be used by infrastructure. So the bitmap > could be elided for a bb flag check (but we need to clear that flag > at the end of processing). Not sure if it's worth to add a machinery > to dynamically assign pass-specific flags... it would at least be > less error prone. Sth to think about. > > So -- I think the patch is ok with the two indirections removed, > the rest can be optimized as followup. Hi, This is the updated patch. I moved checks on ENTRY/EXIT blocks under outofssa_p, as well as changed vec_bbs into object. Note bmp_bbs is kept in pointer so that we can avoid allocating memory in out-of-ssa case. Bootstrap and test ongoing. Is it OK? Thanks, bin > > Thanks, > Richard. > > >> Thanks, >> bin >> 2018-05-15 Bin Cheng > >> * tree-outof-ssa.c (tree-ssa.h, tree-dfa.h): Include header files. >> (create_default_def, for_all_parms): Moved from tree-ssa-coalesce.c. >> (parm_default_def_partition_arg): Ditto. >> (set_parm_default_def_partition): Ditto. >> (get_parm_default_def_partitions): Ditto and make it static. >> (get_undefined_value_partitions): Ditto and make it static. >> (remove_ssa_form): Refactor call to init_var_map here. >> * tree-ssa-coalesce.c (build_ssa_conflict_graph): Support live range >> computation for loop region. >> (coalesce_partitions, compute_optimized_partition_bases): Ditto. >> (register_default_def): Delete. >> (for_all_parms, create_default_def): Move to tree-outof-ssa.c. >> (parm_default_def_partition_arg): Ditto. >> (set_parm_default_def_partition): Ditto. >> (get_parm_default_def_partitions): Ditto and make it static. >> (get_undefined_value_partitions): Ditto and make it static. >> (coalesce_with_default, coalesce_with_default): Update comment. >> (create_coalesce_list_for_region): New func factored out from >> create_outofssa_var_map. >> (populate_coalesce_list_for_outofssa): New func factored out from >> create_outofssa_var_map and coalesce_ssa_name. >> (create_outofssa_var_map): Delete. >> (coalesce_ssa_name): Refactor to support live range computation. >> * tree-ssa-coalesce.h (coalesce_ssa_name): Change decl. >> (get_parm_default_def_partitions): Delete. >> (get_undefined_value_partitions): Ditto. >> * tree-ssa-live.c (init_var_map, delete_var_map): Support live range >> computation for loop region. >> (new_tree_live_info, loe_visit_block): Ditto. >> (live_worklist, set_var_live_on_entry): Ditto. >> (calculate_live_on_exit, verify_live_on_entry): Ditto. >> * tree-ssa-live.h (struct _var_map): New fields. >> (init_var_map): Change decl. >> (region_contains_p): New.