[PATCH] PR71275 ira.c bb_loop_depth

[Alan Modra]

This fixes lack of bb_loop_depth info in some of the early parts of
ira, which has been the case for quite some time.  All active branches
return 0 from bb_loop_depth() in update_equiv_regs, but whether that
actually causes mis-optimization anywhere but trunk is yet to be
determined.

I played a little with trying to consolidate this loop_optimizer_init
call with one that occurs a little later, but ran into ICEs.  (We now
have four calls to loop_optimizer_init in ira.c.)

Bootstrapped and regression tested powerpc64le-linux and x86_64-linux.
OK to apply?

        PR rtl-optimization/71275
        * ira.c (ira): Call loop_optimizer_init to set up bb_loop_depth
        for update_equiv_regs and combine_and_move_insns.

diff --git a/gcc/ira.c b/gcc/ira.c
index 55b4bd7..1b269ea 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -5171,6 +5171,7 @@ ira (FILE *f)
     ira_set_pseudo_classes (true, ira_dump_file);
 
   init_alias_analysis ();
+  loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
   reg_equiv = XCNEWVEC (struct equivalence, max_reg_num ());
   update_equiv_regs ();
 
@@ -5186,6 +5187,7 @@ ira (FILE *f)
   if (optimize)
     add_store_equivs ();
 
+  loop_optimizer_finalize ();
   end_alias_analysis ();
   free (reg_equiv);
 

-- 
Alan Modra
Australia Development Lab, IBM