From 071d19832d788422034a3b052ff7ce91e1010344 Mon Sep 17 00:00:00 2001
From: dingguangya <dingguangya1@huawei.com>
Date: Mon, 28 Feb 2022 16:52:58 +0800
Subject: [PATCH 32/32] [Autoprefetch] Prune invaild loops containing edges whose
 probability exceeds 1

Skip auto prefetch analysis if the loop contains the bb in which the sum
of its outgoing edge probabilities is greater than 1.
---
 gcc/testsuite/gcc.dg/autoprefetch/autoprefetch.exp   |  2 +-
 .../gcc.dg/autoprefetch/branch-weighted-prefetch.c   |  8 ++++----
 gcc/tree-ssa-loop-prefetch.c                         | 12 ++++++++++++
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/autoprefetch/autoprefetch.exp b/gcc/testsuite/gcc.dg/autoprefetch/autoprefetch.exp
index a7408e338..7cae630a2 100644
--- a/gcc/testsuite/gcc.dg/autoprefetch/autoprefetch.exp
+++ b/gcc/testsuite/gcc.dg/autoprefetch/autoprefetch.exp
@@ -20,7 +20,7 @@ load_lib target-supports.exp
 # Initialize `dg'.
 dg-init
 
-gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.c]] \
+dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.c]] \
 	"" "-fprefetch-loop-arrays"
 
 # All done.
diff --git a/gcc/testsuite/gcc.dg/autoprefetch/branch-weighted-prefetch.c b/gcc/testsuite/gcc.dg/autoprefetch/branch-weighted-prefetch.c
index c63c5e5cb..ab537cb29 100644
--- a/gcc/testsuite/gcc.dg/autoprefetch/branch-weighted-prefetch.c
+++ b/gcc/testsuite/gcc.dg/autoprefetch/branch-weighted-prefetch.c
@@ -1,5 +1,5 @@
-/* { dg-do compile } */
-/* { dg-options "-O2 -fprefetch-loop-arrays=2 --param min-insn-to-prefetch-ratio=5 --param simultaneous-prefetches=100 -fdump-tree-aprefetch-details -fdump-tree-optimized" } */
+/* { dg-do compile { target { aarch64*-*-linux* } } } */
+/* { dg-options "-O2 -fprefetch-loop-arrays=2 --param min-insn-to-prefetch-ratio=5 --param simultaneous-prefetches=100 --param l1-cache-size=64 --param l1-cache-line-size=32 -fdump-tree-aprefetch-details -fdump-tree-optimized" } */
 #define N 10000000
 
 long long a[N];
@@ -18,5 +18,5 @@ long long func ()
 
   return sum;
 }
-/* { dg-final { scan-tree-dump-times "Ahead 40" 1 "aprefetch" } } */
-/* { dg-final { scan-tree-dump-times "builtin_prefetch" 1 "optimized" } } */
\ No newline at end of file
+/* { dg-final { scan-tree-dump "Calculating prefetch distance using bb branch weighting method" "aprefetch" } } */
+/* { dg-final { scan-tree-dump "builtin_prefetch" "optimized" } } */
\ No newline at end of file
diff --git a/gcc/tree-ssa-loop-prefetch.c b/gcc/tree-ssa-loop-prefetch.c
index 673f453a4..0d992d8f6 100644
--- a/gcc/tree-ssa-loop-prefetch.c
+++ b/gcc/tree-ssa-loop-prefetch.c
@@ -2267,6 +2267,15 @@ traverse_prune_bb_branch (hash_map <basic_block, bb_bp> &bb_branch_prob,
 			     && bb_bp_node->false_edge_bb == NULL))
     return false;
 
+  /* Do not process the loop with a bb branch probability of an abnormal
+     value.  */
+  if (bb_bp_node->true_edge_prob + bb_bp_node->false_edge_prob > 1)
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "bb branch probability is abnormal\n");
+      return false;
+    }
+
   if (current_bb == latch_bb)
     {
       max_path--;
@@ -2409,6 +2418,9 @@ estimate_num_loop_insns (struct loop *loop, eni_weights *weights)
 	  dump_loop_bb (loop);
 	  return 0;
 	}
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "Calculating prefetch distance using bb branch "
+			    "weighting method\n");
     }
 
   for (unsigned i = 0; i < loop->num_nodes; i++)
-- 
2.27.0