tree-vrp.c (find_assert_locations): Pre-seed live bitmaps for loop latches from header PHI arguments from the latch...

* tree-vrp.c (find_assert_locations): Pre-seed live bitmaps for loop
	latches from header PHI arguments from the latch edge.

        * gcc.dg/unroll_1.c: Add -fno-tree-vrp to dg-options.
        * gcc.dg/unroll_2.c: Likewise.
        * gcc.dg/unroll_3.c: Likewise.
        * gcc.dg/unroll_4.c: Likewise.
	* gcc.dg/vrp90.c: New test.

From-SVN: r204515

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2013-11-07  Richard Biener  <rguenther@suse.de>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	* tree-vrp.c (find_assert_locations): Pre-seed live bitmaps for loop
+	latches from header PHI arguments from the latch edge.
+
 2013-11-07  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/58176

gcc/testsuite/ChangeLog

@@ -1,3 +1,11 @@
+2013-11-07  Jakub Jelinek  <jakub@redhat.com>
+
+        * gcc.dg/unroll_1.c: Add -fno-tree-vrp to dg-options.
+        * gcc.dg/unroll_2.c: Likewise.
+        * gcc.dg/unroll_3.c: Likewise.
+        * gcc.dg/unroll_4.c: Likewise.
+	* gcc.dg/vrp90.c: New test.
+
 2013-11-07  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/58176

gcc/testsuite/gcc.dg/tree-ssa/vrp90.c

@@ -0,0 +1,36 @@
+/* { dg-do link } */
+/* { dg-options "-O2 -fdump-tree-vrp1" } */
+/* { dg-final { scan-tree-dump-not "link_error" "vrp1"} } */
+/* { dg-final { cleanup-tree-dump "vrp1" } } */
+
+extern void link_error (void);
+
+__attribute__((noinline, noclone)) int
+foo (unsigned int n, int r)
+{
+  int i;
+  if (n > 0)
+    {
+      asm ("");
+      if (n < 10)
+	{
+	  asm ("");
+	  do
+	    {
+	      --n;
+	      r *= 2;
+	      if (n >= 9)
+		link_error ();
+	    }
+	  while (n > 0);
+	}
+    }
+  return r + n;
+}
+
+int
+main ()
+{
+  foo (7, 2);
+  return 0;
+}

gcc/testsuite/gcc.dg/unroll_1.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-rtl-loop2_unroll=stderr -fno-peel-loops -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll" } */
+/* { dg-options "-O2 -fdump-rtl-loop2_unroll=stderr -fno-peel-loops -fno-tree-vrp -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll" } */
 
 unsigned a[100], b[100];
 inline void bar()

gcc/testsuite/gcc.dg/unroll_2.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-rtl-loop2_unroll -fno-peel-loops -fdisable-tree-cunroll=foo -fdisable-tree-cunrolli=foo -fenable-rtl-loop2_unroll" } */
+/* { dg-options "-O2 -fdump-rtl-loop2_unroll -fno-peel-loops -fno-tree-vrp -fdisable-tree-cunroll=foo -fdisable-tree-cunrolli=foo -fenable-rtl-loop2_unroll" } */
 
 unsigned a[100], b[100];
 inline void bar()

gcc/testsuite/gcc.dg/unroll_3.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-rtl-loop2_unroll -fno-peel-loops -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll=foo" } */
+/* { dg-options "-O2 -fdump-rtl-loop2_unroll -fno-peel-loops -fno-tree-vrp -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll=foo" } */
 
 unsigned a[100], b[100];
 inline void bar()

gcc/testsuite/gcc.dg/unroll_4.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-rtl-loop2_unroll -fno-peel-loops -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll=foo2" } */
+/* { dg-options "-O2 -fdump-rtl-loop2_unroll -fno-peel-loops -fno-tree-vrp -fdisable-tree-cunroll -fdisable-tree-cunrolli -fenable-rtl-loop2_unroll=foo2" } */
 
 unsigned a[100], b[100];
 inline void bar()

gcc/tree-vrp.c

@@ -5904,6 +5904,34 @@ find_assert_locations (void)
   for (i = 0; i < rpo_cnt; ++i)
     bb_rpo[rpo[i]] = i;
 
+  /* Pre-seed loop latch liveness from loop header PHI nodes.  Due to
+     the order we compute liveness and insert asserts we otherwise
+     fail to insert asserts into the loop latch.  */
+  loop_p loop;
+  loop_iterator li;
+  FOR_EACH_LOOP (li, loop, 0)
+    {
+      i = loop->latch->index;
+      unsigned int j = single_succ_edge (loop->latch)->dest_idx;
+      for (gimple_stmt_iterator gsi = gsi_start_phis (loop->header);
+	   !gsi_end_p (gsi); gsi_next (&gsi))
+	{
+	  gimple phi = gsi_stmt (gsi);
+	  if (virtual_operand_p (gimple_phi_result (phi)))
+	    continue;
+	  tree arg = gimple_phi_arg_def (phi, j);
+	  if (TREE_CODE (arg) == SSA_NAME)
+	    {
+	      if (live[i] == NULL)
+		{
+		  live[i] = sbitmap_alloc (num_ssa_names);
+		  bitmap_clear (live[i]);
+		}
+	      bitmap_set_bit (live[i], SSA_NAME_VERSION (arg));
+	    }
+	}
+    }
+
   need_asserts = false;
   for (i = rpo_cnt - 1; i >= 0; --i)
     {