From: Jan Hubicka <jh@suse.cz>
Date: Sun, 16 Jul 2023 21:53:56 +0000 (+0200)
Subject: Avoid double profile udpate in try_peel_loop
X-Git-Tag: basepoints/gcc-15~7595
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1d203d4c90adb064edfa9680768d1f83a41f17e0;p=thirdparty%2Fgcc.git

Avoid double profile udpate in try_peel_loop

try_peel_loop uses gimple_duplicate_loop_body_to_header_edge which subtracts the profile
from the original loop. However then it tries to scale the profile in a wrong way
(it forces header count to be entry count).

This eliminates to profile misupdates in the internal loop of sphinx3.

gcc/ChangeLog:

	PR middle-end/110649
	* tree-ssa-loop-ivcanon.cc (try_peel_loop): Avoid double profile update.
---

diff --git a/gcc/tree-ssa-loop-ivcanon.cc b/gcc/tree-ssa-loop-ivcanon.cc
index 0117dbfc91b1..bdb738af7a8a 100644
--- a/gcc/tree-ssa-loop-ivcanon.cc
+++ b/gcc/tree-ssa-loop-ivcanon.cc
@@ -1152,6 +1152,7 @@ try_peel_loop (class loop *loop,
     }
   if (may_be_zero)
     bitmap_clear_bit (wont_exit, 1);
+
   if (!gimple_duplicate_loop_body_to_header_edge (
 	loop, loop_preheader_edge (loop), npeel, wont_exit, exit,
 	&edges_to_remove, DLTHE_FLAG_UPDATE_FREQ))
@@ -1168,18 +1169,6 @@ try_peel_loop (class loop *loop,
   adjust_loop_info_after_peeling (loop, npeel, true);
   profile_count entry_count = profile_count::zero ();
 
-  edge e;
-  edge_iterator ei;
-  FOR_EACH_EDGE (e, ei, loop->header->preds)
-    if (e->src != loop->latch)
-      {
-	if (e->src->count.initialized_p ())
-	  entry_count += e->src->count;
-	gcc_assert (!flow_bb_inside_loop_p (loop, e->src));
-      }
-  profile_probability p;
-  p = entry_count.probability_in (loop->header->count);
-  scale_loop_profile (loop, p, -1);
   bitmap_set_bit (peeled_loops, loop->num);
   return true;
 }