[013/nnn] poly_int: same_addr_size_stores_p

[Richard Sandiford]

This patch makes tree-ssa-alias.c:same_addr_size_stores_p handle
poly_int sizes and offsets.


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

gcc/
        * tree-ssa-alias.c (same_addr_size_stores_p): Take the offsets and
        sizes as poly_int64s rather than HOST_WIDE_INTs.

Index: gcc/tree-ssa-alias.c
===================================================================
--- gcc/tree-ssa-alias.c        2017-10-23 16:52:20.150440950 +0100
+++ gcc/tree-ssa-alias.c        2017-10-23 17:01:49.579064221 +0100
@@ -2322,14 +2322,14 @@ stmt_may_clobber_ref_p (gimple *stmt, tr
    address.  */
 
 static bool
-same_addr_size_stores_p (tree base1, HOST_WIDE_INT offset1, HOST_WIDE_INT 
size1,
-                        HOST_WIDE_INT max_size1,
-                        tree base2, HOST_WIDE_INT offset2, HOST_WIDE_INT size2,
-                        HOST_WIDE_INT max_size2)
+same_addr_size_stores_p (tree base1, poly_int64 offset1, poly_int64 size1,
+                        poly_int64 max_size1,
+                        tree base2, poly_int64 offset2, poly_int64 size2,
+                        poly_int64 max_size2)
 {
   /* Offsets need to be 0.  */
-  if (offset1 != 0
-      || offset2 != 0)
+  if (maybe_nonzero (offset1)
+      || maybe_nonzero (offset2))
     return false;
 
   bool base1_obj_p = SSA_VAR_P (base1);
@@ -2348,17 +2348,19 @@ same_addr_size_stores_p (tree base1, HOS
   tree memref = base1_memref_p ? base1 : base2;
 
   /* Sizes need to be valid.  */
-  if (max_size1 == -1 || max_size2 == -1
-      || size1 == -1 || size2 == -1)
+  if (!known_size_p (max_size1)
+      || !known_size_p (max_size2)
+      || !known_size_p (size1)
+      || !known_size_p (size2))
     return false;
 
   /* Max_size needs to match size.  */
-  if (max_size1 != size1
-      || max_size2 != size2)
+  if (may_ne (max_size1, size1)
+      || may_ne (max_size2, size2))
     return false;
 
   /* Sizes need to match.  */
-  if (size1 != size2)
+  if (may_ne (size1, size2))
     return false;
 
 
@@ -2386,10 +2388,9 @@ same_addr_size_stores_p (tree base1, HOS
 
   /* Check that the object size is the same as the store size.  That ensures us
      that ptr points to the start of obj.  */
-  if (!tree_fits_shwi_p (DECL_SIZE (obj)))
-    return false;
-  HOST_WIDE_INT obj_size = tree_to_shwi (DECL_SIZE (obj));
-  return obj_size == size1;
+  return (DECL_SIZE (obj)
+         && poly_int_tree_p (DECL_SIZE (obj))
+         && must_eq (wi::to_poly_offset (DECL_SIZE (obj)), size1));
 }
 
 /* If STMT kills the memory reference REF return true, otherwise