Files
mercury/tests/hard_coded/bit_twiddle_uint16.m
Julien Fischer ee76350044 Add more operations on 16-bit integers.
library/int16.m:
library/uint16.m:
    Add num_zeros/1, num_ones/1, num_leading_zeros/1, num_trailing_zeros/1
    and reverse_bits/1.

tests/hard_coded/Mmakefile:
tests/hard_coded/bit_twiddle_uint16.{m,exp}:
tests/hard_coded/bit_twiddle_int16.{m,exp}:
    Add tests of the above.
2018-03-31 22:29:25 +11:00

132 lines
3.8 KiB
Mathematica

%---------------------------------------------------------------------------%
% vim: ft=mercury ts=4 sw=4 et wm=0 tw=0
%---------------------------------------------------------------------------%
% Test bit twiddling operations for unsigned 16-bit integers.
:- module bit_twiddle_uint16.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%
:- implementation.
:- import_module uint16.
:- import_module list.
:- import_module string.
%---------------------------------------------------------------------------%
main(!IO) :-
run_twiddle_test(uint16.num_zeros, "num_zeros", !IO),
io.nl(!IO),
run_twiddle_test(uint16.num_ones, "num_ones", !IO),
io.nl(!IO),
run_twiddle_test(uint16.num_leading_zeros, "num_leading_zeros", !IO),
io.nl(!IO),
run_twiddle_test(uint16.num_trailing_zeros, "num_trailing_zeros", !IO),
io.nl(!IO),
run_twiddle_test_b(uint16.reverse_bits, "reverse_bits", !IO),
io.nl(!IO),
run_twiddle_test_b(uint16.reverse_bytes, "reverse_bytes", !IO).
%---------------------------------------------------------------------------%
% Test uint16 -> int functions.
:- pred run_twiddle_test((func(uint16) = int)::in, string::in,
io::di, io::uo) is det.
run_twiddle_test(Func, Desc, !IO) :-
io.format("*** Test function '%s' ***\n\n", [s(Desc)], !IO),
As = numbers,
list.foldl(run_twiddle_test_2(Func, Desc), As, !IO).
:- pred run_twiddle_test_2((func(uint16) = int)::in, string::in,
uint16::in, io::di, io::uo) is det.
run_twiddle_test_2(Func, Desc, A, !IO) :-
Result = Func(A),
int_to_string(Result, ResultStr),
io.format("%s(%s) = %s\n",
[s(Desc), s(to_binary_string_lz(A)), s(ResultStr)], !IO).
%---------------------------------------------------------------------------%
% Test uint16 -> uint16 functions.
:- pred run_twiddle_test_b((func(uint16) = uint16)::in, string::in,
io::di, io::uo) is det.
run_twiddle_test_b(Func, Desc, !IO) :-
io.format("*** Test function '%s' ***\n\n", [s(Desc)], !IO),
As = numbers,
list.foldl(run_twiddle_test_b_2(Func, Desc), As, !IO).
:- pred run_twiddle_test_b_2((func(uint16) = uint16)::in, string::in,
uint16::in, io::di, io::uo) is det.
run_twiddle_test_b_2(Func, Desc, A, !IO) :-
Result = Func(A),
ResultStr = to_binary_string_lz(Result),
io.format("%s(%s) = %s\n",
[s(Desc), s(to_binary_string_lz(A)), s(ResultStr)], !IO).
%---------------------------------------------------------------------------%
:- func numbers = list(uint16).
numbers = [
0_u16,
1_u16,
2_u16,
8_u16,
16_u16,
255_u16,
65_535_u16
].
%---------------------------------------------------------------------------%
:- func to_binary_string_lz(uint16::in) = (string::uo) is det.
:- pragma foreign_proc("C",
to_binary_string_lz(U::in) = (S::uo),
[will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail],
"
int i = 16;
MR_allocate_aligned_string_msg(S, 16, MR_ALLOC_ID);
S[16] = '\\0';
while (i >= 0) {
i--;
S[i] = (U & 1) ? '1' : '0';
U = U >> 1;
}
").
:- pragma foreign_proc("C#",
to_binary_string_lz(U::in) = (S::uo),
[will_not_call_mercury, promise_pure, thread_safe],
"
S = System.Convert.ToString(U, 2).PadLeft(16, '0');
").
:- pragma foreign_proc("Java",
to_binary_string_lz(U::in) = (S::uo),
[will_not_call_mercury, promise_pure, thread_safe],
"
S = java.lang.String.format(""%16s"",
java.lang.Integer.toBinaryString(U & 0xffff)).replace(' ', '0');
").
%---------------------------------------------------------------------------%
:- end_module bit_twiddle_uint16.
%---------------------------------------------------------------------------%