poly_int: MEM_REF offsets

This patch allows MEM_REF offsets to be polynomial, with mem_ref_offset
now returning a poly_offset_int instead of an offset_int.  The
non-mechanical changes to callers of mem_ref_offset were handled by
previous patches.

2017-12-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* fold-const.h (mem_ref_offset): Return a poly_offset_int rather
	than an offset_int.
	* tree.c (mem_ref_offset): Likewise.
	(build_simple_mem_ref_loc): Treat MEM_REF offsets as poly_ints.
	* builtins.c (get_object_alignment_2): Likewise.
	* expr.c (get_inner_reference, expand_expr_real_1): Likewise.
	* gimple-fold.c (get_base_constructor): Likewise.
	* gimple-ssa-strength-reduction.c (restructure_reference): Likewise.
	* gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref):
	Likewise.
	* ipa-polymorphic-call.c
	(ipa_polymorphic_call_context::ipa_polymorphic_call_context): Likewise.
	* ipa-prop.c (compute_complex_assign_jump_func): Likewise.
	(get_ancestor_addr_info): Likewise.
	* ipa-param-manipulation.c (ipa_get_adjustment_candidate): Likewise.
	* match.pd: Likewise.
	* tree-data-ref.c (dr_analyze_innermost): Likewise.
	* tree-dfa.c (get_addr_base_and_unit_offset_1): Likewise.
	* tree-eh.c (tree_could_trap_p): Likewise.
	* tree-object-size.c (addr_object_size): Likewise.
	* tree-ssa-address.c (copy_ref_info): Likewise.
	* tree-ssa-alias.c (indirect_ref_may_alias_decl_p): Likewise.
	(indirect_refs_may_alias_p): Likewise.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Likewise.
	* tree-ssa.c (maybe_rewrite_mem_ref_base): Likewise.
	(non_rewritable_mem_ref_base): Likewise.
	* tree-vect-data-refs.c (vect_check_gather_scatter): Likewise.
	* tree-vrp.c (vrp_prop::check_array_ref): Likewise.
	* varasm.c (decode_addr_const): Likewise.

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

From-SVN: r255930

1 files changed, 17 insertions, 11 deletions

diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index 86a587d..2707cf8 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -820,16 +820,16 @@ dr_analyze_innermost (innermost_loop_behavior *drb, tree ref,
     }
 
   /* Calculate the alignment and misalignment for the inner reference.  */
-  unsigned int HOST_WIDE_INT base_misalignment;
-  unsigned int base_alignment;
-  get_object_alignment_1 (base, &base_alignment, &base_misalignment);
+  unsigned int HOST_WIDE_INT bit_base_misalignment;
+  unsigned int bit_base_alignment;
+  get_object_alignment_1 (base, &bit_base_alignment, &bit_base_misalignment);
 
   /* There are no bitfield references remaining in BASE, so the values
      we got back must be whole bytes.  */
-  gcc_assert (base_alignment % BITS_PER_UNIT == 0
-	      && base_misalignment % BITS_PER_UNIT == 0);
-  base_alignment /= BITS_PER_UNIT;
-  base_misalignment /= BITS_PER_UNIT;
+  gcc_assert (bit_base_alignment % BITS_PER_UNIT == 0
+	      && bit_base_misalignment % BITS_PER_UNIT == 0);
+  unsigned int base_alignment = bit_base_alignment / BITS_PER_UNIT;
+  poly_int64 base_misalignment = bit_base_misalignment / BITS_PER_UNIT;
 
   if (TREE_CODE (base) == MEM_REF)
     {
@@ -837,8 +837,8 @@ dr_analyze_innermost (innermost_loop_behavior *drb, tree ref,
 	{
 	  /* Subtract MOFF from the base and add it to POFFSET instead.
 	     Adjust the misalignment to reflect the amount we subtracted.  */
-	  offset_int moff = mem_ref_offset (base);
-	  base_misalignment -= moff.to_short_addr ();
+	  poly_offset_int moff = mem_ref_offset (base);
+	  base_misalignment -= moff.force_shwi ();
 	  tree mofft = wide_int_to_tree (sizetype, moff);
 	  if (!poffset)
 	    poffset = mofft;
@@ -925,8 +925,14 @@ dr_analyze_innermost (innermost_loop_behavior *drb, tree ref,
   drb->offset = fold_convert (ssizetype, offset_iv.base);
   drb->init = init;
   drb->step = step;
-  drb->base_alignment = base_alignment;
-  drb->base_misalignment = base_misalignment & (base_alignment - 1);
+  if (known_misalignment (base_misalignment, base_alignment,
+			  &drb->base_misalignment))
+    drb->base_alignment = base_alignment;
+  else
+    {
+      drb->base_alignment = known_alignment (base_misalignment);
+      drb->base_misalignment = 0;
+    }
   drb->offset_alignment = highest_pow2_factor (offset_iv.base);
   drb->step_alignment = highest_pow2_factor (step);