[gcc r15-280] Avoid re-allocating vector

[Richard Biener via Gcc-cvs]

https://gcc.gnu.org/g:cb4e2685a3e73474246adda356595f72fcd43827

commit r15-280-gcb4e2685a3e73474246adda356595f72fcd43827
Author: Richard Biener <rguent...@suse.de>
Date:   Wed Apr 17 13:20:40 2024 +0200

    Avoid re-allocating vector
    
    The following avoids re-allocating the var map BB vector by
    pre-allocating it to the exact size needed when operating on the
    whole function.
    
            * tree-ssa-live.cc (init_var_map): Pre-allocate vec_bbs vector
            to the correct size and use quick_push.

Diff:
---
 gcc/tree-ssa-live.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/tree-ssa-live.cc b/gcc/tree-ssa-live.cc
index fa6be2fced3..e6ae551a457 100644
--- a/gcc/tree-ssa-live.cc
+++ b/gcc/tree-ssa-live.cc
@@ -113,8 +113,10 @@ init_var_map (int size, class loop *loop, bitmap bitint)
       map->outofssa_p = bitint == NULL;
       map->bitint = bitint;
       basic_block bb;
+      map->vec_bbs.reserve_exact (n_basic_blocks_for_fn (cfun)
+                                 - NUM_FIXED_BLOCKS);
       FOR_EACH_BB_FN (bb, cfun)
-       map->vec_bbs.safe_push (bb);
+       map->vec_bbs.quick_push (bb);
     }
   return map;
 }