poly_int: aff_tree

This patch changes the type of aff_tree::offset from widest_int to
poly_widest_int and adjusts the function interfaces in the same way.

2017-12-20  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree-affine.h (aff_tree::offset): Change from widest_int
	to poly_widest_int.
	(wide_int_ext_for_comb): Delete.
	(aff_combination_const, aff_comb_cannot_overlap_p): Take the
	constants as poly_widest_int rather than widest_int.
	(aff_combination_constant_multiple_p): Return the multiplier
	as a poly_widest_int.
	(aff_combination_zero_p, aff_combination_singleton_var_p): Handle
	polynomial offsets.
	* tree-affine.c (wide_int_ext_for_comb): Make original widest_int
	version static and add an overload for poly_widest_int.
	(aff_combination_const, aff_combination_add_cst)
	(wide_int_constant_multiple_p, aff_comb_cannot_overlap_p): Take
	the constants as poly_widest_int rather than widest_int.
	(tree_to_aff_combination): Generalize INTEGER_CST case to
	poly_int_tree_p.
	(aff_combination_to_tree): Track offsets as poly_widest_ints.
	(aff_combination_add_product, aff_combination_mult): Handle
	polynomial offsets.
	(aff_combination_constant_multiple_p): Return the multiplier
	as a poly_widest_int.
	* tree-predcom.c (determine_offset): Return the offset as a
	poly_widest_int.
	(split_data_refs_to_components, suitable_component_p): Update
	accordingly.
	(valid_initializer_p): Update call to
	aff_combination_constant_multiple_p.
	* tree-ssa-address.c (addr_to_parts): Handle polynomial offsets.
	* tree-ssa-loop-ivopts.c (get_address_cost_ainc): Take the step
	as a poly_int64 rather than a HOST_WIDE_INT.
	(get_address_cost): Handle polynomial offsets.
	(iv_elimination_compare_lt): Likewise.
	(rewrite_use_nonlinear_expr): Likewise.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r255888

1 files changed, 63 insertions, 27 deletions

diff --git a/gcc/tree-affine.c b/gcc/tree-affine.c
index 47f56bf..3869b0b 100644
--- a/gcc/tree-affine.c
+++ b/gcc/tree-affine.c
@@ -34,12 +34,20 @@ along with GCC; see the file COPYING3.  If not see
 
 /* Extends CST as appropriate for the affine combinations COMB.  */
 
-widest_int
+static widest_int
 wide_int_ext_for_comb (const widest_int &cst, tree type)
 {
   return wi::sext (cst, TYPE_PRECISION (type));
 }
 
+/* Likewise for polynomial offsets.  */
+
+static poly_widest_int
+wide_int_ext_for_comb (const poly_widest_int &cst, tree type)
+{
+  return wi::sext (cst, TYPE_PRECISION (type));
+}
+
 /* Initializes affine combination COMB so that its value is zero in TYPE.  */
 
 static void
@@ -57,7 +65,7 @@ aff_combination_zero (aff_tree *comb, tree type)
 /* Sets COMB to CST.  */
 
 void
-aff_combination_const (aff_tree *comb, tree type, const widest_int &cst)
+aff_combination_const (aff_tree *comb, tree type, const poly_widest_int &cst)
 {
   aff_combination_zero (comb, type);
   comb->offset = wide_int_ext_for_comb (cst, comb->type);;
@@ -190,7 +198,7 @@ aff_combination_add_elt (aff_tree *comb, tree elt, const widest_int &scale_in)
 /* Adds CST to C.  */
 
 static void
-aff_combination_add_cst (aff_tree *c, const widest_int &cst)
+aff_combination_add_cst (aff_tree *c, const poly_widest_int &cst)
 {
   c->offset = wide_int_ext_for_comb (c->offset + cst, c->type);
 }
@@ -268,10 +276,6 @@ tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
   code = TREE_CODE (expr);
   switch (code)
     {
-    case INTEGER_CST:
-      aff_combination_const (comb, type, wi::to_widest (expr));
-      return;
-
     case POINTER_PLUS_EXPR:
       tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
       tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp);
@@ -423,7 +427,14 @@ tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
       break;
 
     default:
-      break;
+      {
+	if (poly_int_tree_p (expr))
+	  {
+	    aff_combination_const (comb, type, wi::to_poly_widest (expr));
+	    return;
+	  }
+	break;
+      }
     }
 
   aff_combination_elt (comb, type, expr);
@@ -478,7 +489,8 @@ aff_combination_to_tree (aff_tree *comb)
 {
   tree type = comb->type, base = NULL_TREE, expr = NULL_TREE;
   unsigned i;
-  widest_int off, sgn;
+  poly_widest_int off;
+  int sgn;
 
   gcc_assert (comb->n == MAX_AFF_ELTS || comb->rest == NULL_TREE);
 
@@ -502,7 +514,7 @@ aff_combination_to_tree (aff_tree *comb)
 
   /* Ensure that we get x - 1, not x + (-1) or x + 0xff..f if x is
      unsigned.  */
-  if (wi::neg_p (comb->offset))
+  if (known_lt (comb->offset, 0))
     {
       off = -comb->offset;
       sgn = -1;
@@ -588,7 +600,19 @@ aff_combination_add_product (aff_tree *c, const widest_int &coef, tree val,
     }
 
   if (val)
-    aff_combination_add_elt (r, val, coef * c->offset);
+    {
+      if (c->offset.is_constant ())
+	/* Access coeffs[0] directly, for efficiency.  */
+	aff_combination_add_elt (r, val, coef * c->offset.coeffs[0]);
+      else
+	{
+	  /* c->offset is polynomial, so multiply VAL rather than COEF
+	     by it.  */
+	  tree offset = wide_int_to_tree (TREE_TYPE (val), c->offset);
+	  val = fold_build2 (MULT_EXPR, TREE_TYPE (val), val, offset);
+	  aff_combination_add_elt (r, val, coef);
+	}
+    }
   else
     aff_combination_add_cst (r, coef * c->offset);
 }
@@ -607,7 +631,15 @@ aff_combination_mult (aff_tree *c1, aff_tree *c2, aff_tree *r)
     aff_combination_add_product (c1, c2->elts[i].coef, c2->elts[i].val, r);
   if (c2->rest)
     aff_combination_add_product (c1, 1, c2->rest, r);
-  aff_combination_add_product (c1, c2->offset, NULL, r);
+  if (c2->offset.is_constant ())
+    /* Access coeffs[0] directly, for efficiency.  */
+    aff_combination_add_product (c1, c2->offset.coeffs[0], NULL, r);
+  else
+    {
+      /* c2->offset is polynomial, so do the multiplication in tree form.  */
+      tree offset = wide_int_to_tree (c2->type, c2->offset);
+      aff_combination_add_product (c1, 1, offset, r);
+    }
 }
 
 /* Returns the element of COMB whose value is VAL, or NULL if no such
@@ -776,27 +808,28 @@ free_affine_expand_cache (hash_map<tree, name_expansion *> **cache)
    is set to true.  */
 
 static bool
-wide_int_constant_multiple_p (const widest_int &val, const widest_int &div,
-			      bool *mult_set, widest_int *mult)
+wide_int_constant_multiple_p (const poly_widest_int &val,
+			      const poly_widest_int &div,
+			      bool *mult_set, poly_widest_int *mult)
 {
-  widest_int rem, cst;
+  poly_widest_int rem, cst;
 
-  if (val == 0)
+  if (known_eq (val, 0))
     {
-      if (*mult_set && *mult != 0)
+      if (*mult_set && maybe_ne (*mult, 0))
 	return false;
       *mult_set = true;
       *mult = 0;
       return true;
     }
 
-  if (div == 0)
+  if (maybe_eq (div, 0))
     return false;
 
-  if (!wi::multiple_of_p (val, div, SIGNED, &cst))
+  if (!multiple_p (val, div, &cst))
     return false;
 
-  if (*mult_set && *mult != cst)
+  if (*mult_set && maybe_ne (*mult, cst))
     return false;
 
   *mult_set = true;
@@ -809,12 +842,12 @@ wide_int_constant_multiple_p (const widest_int &val, const widest_int &div,
 
 bool
 aff_combination_constant_multiple_p (aff_tree *val, aff_tree *div,
-				     widest_int *mult)
+				     poly_widest_int *mult)
 {
   bool mult_set = false;
   unsigned i;
 
-  if (val->n == 0 && val->offset == 0)
+  if (val->n == 0 && known_eq (val->offset, 0))
     {
       *mult = 0;
       return true;
@@ -927,23 +960,26 @@ get_inner_reference_aff (tree ref, aff_tree *addr, widest_int *size)
    size SIZE2 at position DIFF cannot overlap.  */
 
 bool
-aff_comb_cannot_overlap_p (aff_tree *diff, const widest_int &size1,
-			   const widest_int &size2)
+aff_comb_cannot_overlap_p (aff_tree *diff, const poly_widest_int &size1,
+			   const poly_widest_int &size2)
 {
   /* Unless the difference is a constant, we fail.  */
   if (diff->n != 0)
     return false;
 
-  if (wi::neg_p (diff->offset))
+  if (!ordered_p (diff->offset, 0))
+    return false;
+
+  if (maybe_lt (diff->offset, 0))
     {
       /* The second object is before the first one, we succeed if the last
 	 element of the second object is before the start of the first one.  */
-      return wi::neg_p (diff->offset + size2 - 1);
+      return known_le (diff->offset + size2, 0);
     }
   else
     {
       /* We succeed if the second object starts after the first one ends.  */
-      return size1 <= diff->offset;
+      return known_le (size1, diff->offset);
     }
 }