From 50bb696a6b4d75a097f22274834f67961fa9e440 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Thu, 11 Dec 2025 18:32:27 +0100 Subject: Add signed integers (arithmetics and some testing not implemented yet) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- libj2_minus_j2i.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 libj2_minus_j2i.c (limited to 'libj2_minus_j2i.c') diff --git a/libj2_minus_j2i.c b/libj2_minus_j2i.c new file mode 100644 index 0000000..bac519f --- /dev/null +++ b/libj2_minus_j2i.c @@ -0,0 +1,95 @@ +/* See LICENSE file for copyright and license details. */ +#include "common.h" +#ifndef TEST + +extern inline void libj2_minus_j2i(struct libj2_j2i *a); +/* TODO Add man page */ + + +#else + +static uintmax_t +random_ju(void) +{ + size_t n = LIBJ2_JU_BIT; + uintmax_t r = 0; + while (n--) + if (rand() < rand()) + r |= (uintmax_t)1 << n; + return r; +} + + +static void +minus_j2i(struct libj2_j2i *a) +{ + struct libj2_j2i r, a_saved = *a; + r = (struct libj2_j2i){111, 222}; + libj2_minus_j2i_to_j2i(a, &r); + EXPECT(libj2_j2i_eq_j2i(a, &a_saved)); + libj2_minus_j2i(a); + EXPECT(libj2_j2i_eq_j2i(a, &r)); +} + + +int +main(void) +{ + unsigned i; + struct libj2_j2i a, b; + uintmax_t v; + + libj2_j2i_zero(&a); + minus_j2i(&a); + EXPECT(libj2_j2i_is_zero(&a)); + + for (i = 1; i < 256; i++) { + libj2_ji_to_j2i((intmax_t)i, &a); + minus_j2i(&a); + EXPECT(libj2_j2i_eq_ji(&a, -(intmax_t)i)); + minus_j2i(&a); + EXPECT(libj2_j2i_eq_ji(&a, (intmax_t)i)); + } + + a = (struct libj2_j2i){.high = 0, .low = 1}; + minus_j2i(&a); + EXPECT(libj2_j2i_eq_j2i(&a, &(struct libj2_j2i){.high = UINTMAX_MAX, .low = UINTMAX_MAX})); + + a = (struct libj2_j2i){.high = UINTMAX_MAX, .low = UINTMAX_MAX}; + minus_j2i(&a); + EXPECT(libj2_j2i_eq_j2i(&a, &(struct libj2_j2i){.high = 0, .low = 1})); + + for (i = 0; i < 256; i++) { + a.high = 0; + a.low = v = random_ju(); + minus_j2i(&a); + EXPECT(a.high == UINTMAX_MAX); + EXPECT(a.low == 0U - v); + + a.high = UINTMAX_MAX; + a.low = v = random_ju(); + minus_j2i(&a); + EXPECT(a.high == 0); + EXPECT(a.low == 0U - v); + } + +#ifdef TODO /* requires libj2_j2i_add_j2i */ + for (i = 0; i < 256; i++) { + a.high = b.high = random_ju() >> 1; + a.low = b.low = random_ju(); + minus_j2i(&a); + libj2_j2i_add_j2i(&a, &b); + EXPECT(libj2_j2i_is_zero(&a)); + + a.high = b.high ^= UINTMAX_MAX; + a.low = b.low ^= UINTMAX_MAX; + minus_j2i(&a); + libj2_j2i_add_j2i(&a, &b); + EXPECT(libj2_j2i_is_zero(&a)); + } +#endif + + return 0; +} + +#endif -- cgit v1.2.3-70-g09d2