This patch changes the bitpos argument to pointer_may_wrap_p from
HOST_WIDE_INT to poly_int64. A later patch makes the callers track
polynomial offsets.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* fold-const.c (pointer_may_wrap_p): Take the offset as a
HOST_WIDE_INT rather than a poly_int64.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c 2017-10-23 17:17:01.429034898 +0100
+++ gcc/fold-const.c 2017-10-23 17:17:05.755450644 +0100
@@ -8421,48 +8421,50 @@ maybe_canonicalize_comparison (location_
expressions like &p->x which can not wrap. */
static bool
-pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
+pointer_may_wrap_p (tree base, tree offset, poly_int64 bitpos)
{
if (!POINTER_TYPE_P (TREE_TYPE (base)))
return true;
- if (bitpos < 0)
+ if (may_lt (bitpos, 0))
return true;
- wide_int wi_offset;
+ poly_wide_int wi_offset;
int precision = TYPE_PRECISION (TREE_TYPE (base));
if (offset == NULL_TREE)
wi_offset = wi::zero (precision);
- else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
+ else if (!poly_int_tree_p (offset) || TREE_OVERFLOW (offset))
return true;
else
- wi_offset = wi::to_wide (offset);
+ wi_offset = wi::to_poly_wide (offset);
bool overflow;
- wide_int units = wi::shwi (bitpos / BITS_PER_UNIT, precision);
- wide_int total = wi::add (wi_offset, units, UNSIGNED, &overflow);
+ poly_wide_int units = wi::shwi (bits_to_bytes_round_down (bitpos),
+ precision);
+ poly_wide_int total = wi::add (wi_offset, units, UNSIGNED, &overflow);
if (overflow)
return true;
- if (!wi::fits_uhwi_p (total))
+ poly_uint64 total_hwi, size;
+ if (!total.to_uhwi (&total_hwi)
+ || !poly_int_tree_p (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (base))),
+ &size)
+ || known_zero (size))
return true;
- HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
- if (size <= 0)
- return true;
+ if (must_le (total_hwi, size))
+ return false;
/* We can do slightly better for SIZE if we have an ADDR_EXPR of an
array. */
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- HOST_WIDE_INT base_size;
-
- base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
- if (base_size > 0 && size < base_size)
- size = base_size;
- }
+ if (TREE_CODE (base) == ADDR_EXPR
+ && poly_int_tree_p (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (base, 0))),
+ &size)
+ && maybe_nonzero (size)
+ && must_le (total_hwi, size))
+ return false;
- return total.to_uhwi () > (unsigned HOST_WIDE_INT) size;
+ return true;
}
/* Return a positive integer when the symbol DECL is known to have
