re PR tree-optimization/86835 (Bogus "is used uninitialized" warning with -ffast-math)

	PR tree-optimization/86835
	* tree-ssa-math-opts.c (insert_reciprocals): Even when inserting
	new_stmt after def_gsi, make sure to insert new_square_stmt after
	that stmt, not 2 stmts before it.

	* gcc.dg/pr86835.c: New test.

From-SVN: r263487

1 files changed, 6 insertions, 6 deletions

diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c
index e32669d..a90d9d2 100644
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -422,6 +422,8 @@ insert_reciprocals (gimple_stmt_iterator *def_gsi, struct occurrence *occ,
 	    gsi_next (&gsi);
 
 	  gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
+	  if (should_insert_square_recip)
+	    gsi_insert_before (&gsi, new_square_stmt, GSI_SAME_STMT);
 	}
       else if (def_gsi && occ->bb == def_gsi->bb)
 	{
@@ -429,21 +431,19 @@ insert_reciprocals (gimple_stmt_iterator *def_gsi, struct occurrence *occ,
 	     never happen if the definition statement can throw, because in
 	     that case the sole successor of the statement's basic block will
 	     dominate all the uses as well.  */
-	  gsi = *def_gsi;
 	  gsi_insert_after (def_gsi, new_stmt, GSI_NEW_STMT);
+	  if (should_insert_square_recip)
+	    gsi_insert_after (def_gsi, new_square_stmt, GSI_NEW_STMT);
 	}
       else
 	{
 	  /* Case 3: insert in a basic block not containing defs/uses.  */
 	  gsi = gsi_after_labels (occ->bb);
 	  gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
+	  if (should_insert_square_recip)
+	    gsi_insert_before (&gsi, new_square_stmt, GSI_SAME_STMT);
 	}
 
-      /* Regardless of which case the reciprocal as inserted in,
-	 we insert the square immediately after the reciprocal.  */
-      if (should_insert_square_recip)
-	gsi_insert_before (&gsi, new_square_stmt, GSI_SAME_STMT);
-
       reciprocal_stats.rdivs_inserted++;
 
       occ->recip_def_stmt = new_stmt;