[085/nnn] poly_int: expand_vector_ubsan_overflow

[Richard Sandiford]

This patch makes expand_vector_ubsan_overflow cope with a polynomial
number of elements.


2017-10-23  Richard Sandiford  <richard.sandif...@linaro.org>
            Alan Hayward  <alan.hayw...@arm.com>
            David Sherwood  <david.sherw...@arm.com>

gcc/
        * internal-fn.c (expand_vector_ubsan_overflow): Handle polynomial
        numbers of elements.

Index: gcc/internal-fn.c
===================================================================
--- gcc/internal-fn.c   2017-10-23 17:11:39.913311438 +0100
+++ gcc/internal-fn.c   2017-10-23 17:22:51.056325855 +0100
@@ -1872,7 +1872,7 @@ expand_mul_overflow (location_t loc, tre
 expand_vector_ubsan_overflow (location_t loc, enum tree_code code, tree lhs,
                              tree arg0, tree arg1)
 {
-  int cnt = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+  poly_uint64 cnt = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
   rtx_code_label *loop_lab = NULL;
   rtx cntvar = NULL_RTX;
   tree cntv = NULL_TREE;
@@ -1882,6 +1882,8 @@ expand_vector_ubsan_overflow (location_t
   tree resv = NULL_TREE;
   rtx lhsr = NULL_RTX;
   rtx resvr = NULL_RTX;
+  unsigned HOST_WIDE_INT const_cnt = 0;
+  bool use_loop_p = (!cnt.is_constant (&const_cnt) || const_cnt > 4);
 
   if (lhs)
     {
@@ -1902,7 +1904,7 @@ expand_vector_ubsan_overflow (location_t
            }
        }
     }
-  if (cnt > 4)
+  if (use_loop_p)
     {
       do_pending_stack_adjust ();
       loop_lab = gen_label_rtx ();
@@ -1921,10 +1923,10 @@ expand_vector_ubsan_overflow (location_t
       rtx arg1r = expand_normal (arg1);
       arg1 = make_tree (TREE_TYPE (arg1), arg1r);
     }
-  for (int i = 0; i < (cnt > 4 ? 1 : cnt); i++)
+  for (unsigned int i = 0; i < (use_loop_p ? 1 : const_cnt); i++)
     {
       tree op0, op1, res = NULL_TREE;
-      if (cnt > 4)
+      if (use_loop_p)
        {
          tree atype = build_array_type_nelts (eltype, cnt);
          op0 = uniform_vector_p (arg0);
@@ -1964,7 +1966,7 @@ expand_vector_ubsan_overflow (location_t
                                  false, false, false, true, &data);
          break;
        case MINUS_EXPR:
-         if (cnt > 4 ? integer_zerop (arg0) : integer_zerop (op0))
+         if (use_loop_p ? integer_zerop (arg0) : integer_zerop (op0))
            expand_neg_overflow (loc, res, op1, true, &data);
          else
            expand_addsub_overflow (loc, MINUS_EXPR, res, op0, op1,
@@ -1978,7 +1980,7 @@ expand_vector_ubsan_overflow (location_t
          gcc_unreachable ();
        }
     }
-  if (cnt > 4)
+  if (use_loop_p)
     {
       struct separate_ops ops;
       ops.code = PLUS_EXPR;
@@ -1991,7 +1993,8 @@ expand_vector_ubsan_overflow (location_t
                                    EXPAND_NORMAL);
       if (ret != cntvar)
        emit_move_insn (cntvar, ret);
-      do_compare_rtx_and_jump (cntvar, GEN_INT (cnt), NE, false,
+      rtx cntrtx = gen_int_mode (cnt, TYPE_MODE (sizetype));
+      do_compare_rtx_and_jump (cntvar, cntrtx, NE, false,
                               TYPE_MODE (sizetype), NULL_RTX, NULL, loop_lab,
                               profile_probability::very_likely ());
     }