This patch makes expand_expr_real_2 cope with polynomial mode sizes
when handling conversions involving a union type.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* expr.c (expand_expr_real_2): When handling conversions involving
unions, apply tree_to_poly_uint64 to the TYPE_SIZE rather than
multiplying int_size_in_bytes by BITS_PER_UNIT. Treat GET_MODE_BISIZE
as a poly_uint64 too.
Index: gcc/expr.c
===================================================================
--- gcc/expr.c 2017-10-23 17:25:30.704136008 +0100
+++ gcc/expr.c 2017-10-23 17:25:34.105013764 +0100
@@ -8354,11 +8354,14 @@ #define REDUCE_BIT_FIELD(expr) (reduce_b
&& !TYPE_REVERSE_STORAGE_ORDER (type));
/* Store this field into a union of the proper type. */
+ poly_uint64 op0_size
+ = tree_to_poly_uint64 (TYPE_SIZE (TREE_TYPE (treeop0)));
+ poly_uint64 union_size = GET_MODE_BITSIZE (mode);
store_field (target,
- MIN ((int_size_in_bytes (TREE_TYPE
- (treeop0))
- * BITS_PER_UNIT),
- (HOST_WIDE_INT) GET_MODE_BITSIZE (mode)),
+ /* The conversion must be constructed so that
+ we know at compile time how many bits
+ to preserve. */
+ ordered_min (op0_size, union_size),
0, 0, 0, TYPE_MODE (valtype), treeop0, 0,
false, false);
}
