================ @@ -3680,6 +3680,41 @@ the arguments. Both arguments and the result have the bitwidth specified by the name of the builtin. These builtins can be used within constant expressions. +``__builtin_stdc_rotate_left`` and ``__builtin_stdc_rotate_right`` +------------------------------------------------------------------ + +**Syntax**: + +.. code-block:: c + + T __builtin_stdc_rotate_left(T value, count) + T __builtin_stdc_rotate_right(T value, count) + +where ``T`` is any unsigned integer type and ``count`` is any integer type. + +**Description**: + +These builtins rotate the bits in ``value`` by ``count`` positions. The +``__builtin_stdc_rotate_left`` builtin rotates bits to the left, while +``__builtin_stdc_rotate_right`` rotates bits to the right. The first +argument (``value``) must be an unsigned integer type, including ``_BitInt`` types. +The second argument (``count``) can be any integer type. The rotation count is +normalized modulo the bit-width of the value being rotated, with negative +counts converted to equivalent positive rotations (e.g., rotating left +by ``-1`` is equivalent to rotating left by ``BitWidth-1``). These builtins can +be used within constant expressions. + +**Example of use**: + +.. code-block:: c + + unsigned char rotated_left = __builtin_stdc_rotate_left((unsigned char)0xB1, 3); + unsigned int rotated_right = __builtin_stdc_rotate_right(0x12345678U, 8); + + unsigned char neg_rotate = __builtin_stdc_rotate_left((unsigned char)0xB1, -1); + + unsigned _BitInt(17) rotated_odd = __builtin_stdc_rotate_left(0x1ABCD, 5); ---------------- erichkeane wrote:
This one doesnt' really look like the toherse :) Does this one work? I'd expect the RHS to have an `unsigned int` (after conversion) type, but the LHS is a narrowing conversion as a result. https://github.com/llvm/llvm-project/pull/160259 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
