diff mbox

Fix PR67121

Message ID alpine.LSU.2.11.1508051429470.19642@zhemvz.fhfr.qr
State New
Headers show

Commit Message

Richard Biener Aug. 5, 2015, 12:30 p.m. UTC 
Similar to if-combine if-conversion invalidates range info on stmts
that are executed unconditionally only after the transform.  Thus
we have to invalidate it.

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

Richard.

2015-08-05  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/67121
	* tree-if-conv.c (combine_blocks): Clear range-info produced
	by stmts no longer executed conditionally.

	* gcc.dg/torture/pr67121.c: New testcase.
diff mbox

Patch

Index: gcc/tree-if-conv.c
===================================================================
--- gcc/tree-if-conv.c	(revision 226612)
+++ gcc/tree-if-conv.c	(working copy)
@@ -2199,9 +2199,11 @@  combine_blocks (struct loop *loop, bool
   /* Merge basic blocks: first remove all the edges in the loop,
      except for those from the exit block.  */
   exit_bb = NULL;
+  bool *predicated = XNEWVEC (bool, orig_loop_num_nodes);
   for (i = 0; i < orig_loop_num_nodes; i++)
     {
       bb = ifc_bbs[i];
+      predicated[i] = !is_true_predicate (bb_predicate (bb));
       free_bb_predicate (bb);
       if (bb_with_exit_edge_p (loop, bb))
 	{
@@ -2259,9 +2261,21 @@  combine_blocks (struct loop *loop, bool
       if (bb == exit_bb || bb == loop->latch)
 	continue;
 
-      /* Make stmts member of loop->header.  */
+      /* Make stmts member of loop->header and clear range info from all stmts
+	 in BB which is now no longer executed conditional on a predicate we
+	 could have derived it from.  */
       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
-	gimple_set_bb (gsi_stmt (gsi), merge_target_bb);
+	{
+	  gimple stmt = gsi_stmt (gsi);
+	  gimple_set_bb (stmt, merge_target_bb);
+	  if (predicated[i])
+	    {
+	      ssa_op_iter i;
+	      tree op;
+	      FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF)
+		reset_flow_sensitive_info (op);
+	    }
+	}
 
       /* Update stmt list.  */
       last = gsi_last_bb (merge_target_bb);
@@ -2281,6 +2295,7 @@  combine_blocks (struct loop *loop, bool
 
   free (ifc_bbs);
   ifc_bbs = NULL;
+  free (predicated);
 }
 
 /* Version LOOP before if-converting it; the original loop
Index: gcc/testsuite/gcc.dg/torture/pr67121.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr67121.c	(revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr67121.c	(working copy)
@@ -0,0 +1,31 @@ 
+/* { dg-do run } */
+
+int a[6], b, c = 226, d, e, f;
+signed char g;
+
+void
+fn1 (int p1)
+{
+  b = a[p1];
+}
+
+int
+main ()
+{
+  a[0] = 1;
+  for (f = 0; f < 9; f++)
+    {
+      signed char h = c;
+      int i = 1;
+      g = h < 0 ? h : h >> i;
+      e = g;
+      for (d = 1; d; d = 0)
+	;
+    }
+  fn1 (g >> 8 & 1);
+
+  if (b != 0) 
+    __builtin_abort (); 
+
+  return 0;
+}