* tree.def (LSHIFT_EXPR, RSHIFT_EXPR): Add commentary.
* tree-cfg.c (verify_gimple_assign_binary): Allow shifts of
fixed-point types, and vectors of the same.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@143061
138bc75d-0d04-0410-961f-
82ee72b054a4
2009-01-04 Richard Sandiford <rdsandiford@googlemail.com>
+ * tree.def (LSHIFT_EXPR, RSHIFT_EXPR): Add commentary.
+ * tree-cfg.c (verify_gimple_assign_binary): Allow shifts of
+ fixed-point types, and vectors of the same.
+
+2009-01-04 Richard Sandiford <rdsandiford@googlemail.com>
+
* config/mips/sync.md (*mb_barrier): Rename to...
(*memory_barrier): ...this.
case LSHIFT_EXPR:
case RSHIFT_EXPR:
+ if (FIXED_POINT_TYPE_P (rhs1_type)
+ && INTEGRAL_TYPE_P (rhs2_type)
+ && useless_type_conversion_p (lhs_type, rhs1_type))
+ return false;
+ /* Fall through. */
+
case LROTATE_EXPR:
case RROTATE_EXPR:
{
case VEC_RSHIFT_EXPR:
{
if (TREE_CODE (rhs1_type) != VECTOR_TYPE
- || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
+ || !(INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
+ || FIXED_POINT_TYPE_P (TREE_TYPE (rhs1_type)))
|| (!INTEGRAL_TYPE_P (rhs2_type)
&& (TREE_CODE (rhs2_type) != VECTOR_TYPE
|| !INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
The second operand is the number of bits to
shift by; it need not be the same type as the first operand and result.
Note that the result is undefined if the second operand is larger
- than or equal to the first operand's type size. */
+ than or equal to the first operand's type size.
+
+ The first operand of a shift can have either an integer or a
+ (non-integer) fixed-point type. We follow the ISO/IEC TR 18037:2004
+ semantics for the latter.
+
+ Rotates are defined for integer types only. */
DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2)
DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2)
DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2)