Merge from trunk revision 5eb9f117a361538834b9740d59219911680717d1.

1 files changed, 22 insertions, 12 deletions

diff --git a/gcc/tree-ssa-loop-prefetch.cc b/gcc/tree-ssa-loop-prefetch.cc
index aebd7c9..b6690b0 100644
--- a/gcc/tree-ssa-loop-prefetch.cc
+++ b/gcc/tree-ssa-loop-prefetch.cc
@@ -1308,8 +1308,6 @@ emit_mfence_after_loop (class loop *loop)
 
       gsi_insert_before (&bsi, call, GSI_NEW_STMT);
     }
-
-  update_ssa (TODO_update_ssa_only_virtuals);
 }
 
 /* Returns true if we can use storent in loop, false otherwise.  */
@@ -1340,23 +1338,27 @@ may_use_storent_in_loop_p (class loop *loop)
 }
 
 /* Marks nontemporal stores in LOOP.  GROUPS contains the description of memory
-   references in the loop.  */
+   references in the loop.  Returns whether we inserted any mfence call.  */
 
-static void
+static bool
 mark_nontemporal_stores (class loop *loop, struct mem_ref_group *groups)
 {
   struct mem_ref *ref;
   bool any = false;
 
   if (!may_use_storent_in_loop_p (loop))
-    return;
+    return false;
 
   for (; groups; groups = groups->next)
     for (ref = groups->refs; ref; ref = ref->next)
       any |= mark_nontemporal_store (ref);
 
   if (any && FENCE_FOLLOWING_MOVNT != NULL_TREE)
-    emit_mfence_after_loop (loop);
+    {
+      emit_mfence_after_loop (loop);
+      return true;
+    }
+  return false;
 }
 
 /* Determines whether we can profitably unroll LOOP FACTOR times, and if
@@ -1874,10 +1876,11 @@ insn_to_prefetch_ratio_too_small_p (unsigned ninsns, unsigned prefetch_count,
 
 
 /* Issue prefetch instructions for array references in LOOP.  Returns
-   true if the LOOP was unrolled.  */
+   true if the LOOP was unrolled and updates NEED_LC_SSA_UPDATE if we need
+   to update SSA for virtual operands and LC SSA for a split edge.  */
 
 static bool
-loop_prefetch_arrays (class loop *loop)
+loop_prefetch_arrays (class loop *loop, bool &need_lc_ssa_update)
 {
   struct mem_ref_group *refs;
   unsigned ahead, ninsns, time, unroll_factor;
@@ -1952,7 +1955,7 @@ loop_prefetch_arrays (class loop *loop)
 					  unroll_factor))
     goto fail;
 
-  mark_nontemporal_stores (loop, refs);
+  need_lc_ssa_update |= mark_nontemporal_stores (loop, refs);
 
   /* Step 4: what to prefetch?  */
   if (!schedule_prefetches (refs, unroll_factor, ahead))
@@ -1980,6 +1983,7 @@ unsigned int
 tree_ssa_prefetch_arrays (void)
 {
   bool unrolled = false;
+  bool need_lc_ssa_update = false;
   int todo_flags = 0;
 
   if (!targetm.have_prefetch ()
@@ -2028,12 +2032,15 @@ tree_ssa_prefetch_arrays (void)
       if (dump_file && (dump_flags & TDF_DETAILS))
 	fprintf (dump_file, "Processing loop %d:\n", loop->num);
 
-      unrolled |= loop_prefetch_arrays (loop);
+      unrolled |= loop_prefetch_arrays (loop, need_lc_ssa_update);
 
       if (dump_file && (dump_flags & TDF_DETAILS))
 	fprintf (dump_file, "\n\n");
     }
 
+  if (need_lc_ssa_update)
+    rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_only_virtuals);
+
   if (unrolled)
     {
       scev_reset ();
@@ -2069,8 +2076,11 @@ public:
   {}
 
   /* opt_pass methods: */
-  virtual bool gate (function *) { return flag_prefetch_loop_arrays > 0; }
-  virtual unsigned int execute (function *);
+  bool gate (function *) final override
+  {
+    return flag_prefetch_loop_arrays > 0;
+  }
+  unsigned int execute (function *) final override;
 
 }; // class pass_loop_prefetch