From 2bf851de6dd3a64f91a72a9afba2b3637dbbe154 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Thu, 4 Dec 2025 19:25:47 +0100 Subject: First commit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- libj2_j2u_xor_j2u.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 libj2_j2u_xor_j2u.c (limited to 'libj2_j2u_xor_j2u.c') diff --git a/libj2_j2u_xor_j2u.c b/libj2_j2u_xor_j2u.c new file mode 100644 index 0000000..c6ee6d1 --- /dev/null +++ b/libj2_j2u_xor_j2u.c @@ -0,0 +1,140 @@ +/* See LICENSE file for copyright and license details. */ +#include "common.h" +#ifndef TEST + +extern inline void libj2_j2u_xor_j2u(struct libj2_j2u *a, const struct libj2_j2u *b); +/* TODO Add man page */ + + +#else + +static void +check(struct libj2_j2u *a, struct libj2_j2u *b, const struct libj2_j2u *expected) +{ + struct libj2_j2u a_saved = *a, b_saved = *b, r; + + r = *a; + libj2_j2u_xor_j2u(&r, b); + EXPECT(libj2_j2u_eq_j2u(b, &b_saved)); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = *a; + libj2_j2u_xor_j2u(&r, &r); + EXPECT(libj2_j2u_is_zero(&r)); + + r = (struct libj2_j2u){111, 222}; + libj2_j2u_xor_j2u_to_j2u(a, b, &r); + EXPECT(libj2_j2u_eq_j2u(a, &a_saved)); + EXPECT(libj2_j2u_eq_j2u(b, &b_saved)); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = *a; + libj2_j2u_xor_j2u_to_j2u(&r, b, &r); + EXPECT(libj2_j2u_eq_j2u(b, &b_saved)); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = *b; + libj2_j2u_xor_j2u_to_j2u(a, &r, &r); + EXPECT(libj2_j2u_eq_j2u(a, &a_saved)); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = (struct libj2_j2u){111, 222}; + libj2_j2u_xor_j2u_to_j2u(a, a, &r); + EXPECT(libj2_j2u_eq_j2u(a, &a_saved)); + EXPECT(libj2_j2u_is_zero(&r)); + + r = *a; + libj2_j2u_xor_j2u_to_j2u(&r, &r, &r); + EXPECT(libj2_j2u_is_zero(&r)); + + if (a->high == 0U) { + r = (struct libj2_j2u){111, 222}; + libj2_ju_xor_j2u_to_j2u(a->low, b, &r); + EXPECT(libj2_j2u_eq_j2u(b, &b_saved)); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = *b; + libj2_ju_xor_j2u_to_j2u(a->low, &r, &r); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + } + + if (b->high == 0U) { + r = *a; + libj2_j2u_xor_ju(&r, b->low); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = (struct libj2_j2u){111, 222}; + libj2_j2u_xor_ju_to_j2u(a, b->low, &r); + EXPECT(libj2_j2u_eq_j2u(a, &a_saved)); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + + r = *a; + libj2_j2u_xor_ju_to_j2u(&r, b->low, &r); + EXPECT(libj2_j2u_eq_j2u(&r, expected)); + } +} + +int +main(void) +{ + unsigned truthtable[] = {0, 1, 1, 0}; + unsigned i, j; + uintmax_t a_bit, b_bit, r_bit; + struct libj2_j2u a, b, r, a_saved; + + srand((unsigned)time(NULL)); + + for (j = 0; j < 128; j++) { + a.high = a.low = 0; + b.high = b.low = 0; + r.high = r.low = 0; + for (i = 0; i < LIBJ2_J2U_BIT; i++) { + a_bit = (uintmax_t)(rand() < rand()); + b_bit = (uintmax_t)(rand() < rand()); + r_bit = truthtable[a_bit * 2U + b_bit]; + if (i < LIBJ2_JU_BIT) { + a.low |= a_bit << i; + b.low |= b_bit << i; + r.low |= r_bit << i; + } else { + a.high |= a_bit << (i - LIBJ2_JU_BIT); + b.high |= b_bit << (i - LIBJ2_JU_BIT); + r.high |= r_bit << (i - LIBJ2_JU_BIT); + } + } + + check(&a, &b, &r); + + a_saved = a; + a.high = 0U; + r.high = 0U; + for (i = 0; i < LIBJ2_JU_BIT; i++) { + r_bit = truthtable[(b.high >> i) & 1U]; + r.high |= r_bit << i; + } + check(&a, &b, &r); + a = a_saved; + + b.high = 0U; + r.high = 0U; + for (i = 0; i < LIBJ2_JU_BIT; i++) { + r_bit = truthtable[((a.high >> i) & 1U) * 2U]; + r.high |= r_bit << i; + } + check(&a, &b, &r); + + r.high = 0U; + r.low = 0U; + for (i = 0; i < LIBJ2_JU_BIT; i++) { + r_bit = truthtable[((a.high >> i) & 1U) * 3U]; + r.high |= r_bit << i; + r_bit = truthtable[((a.low >> i) & 1U) * 3U]; + r.low |= r_bit << i; + } + check(&a, &a, &r); + } + + return 0; +} + +#endif -- cgit v1.2.3-70-g09d2