From 613cf0fcbabee5ec34cab85a933eb3d46845a7cb Mon Sep 17 00:00:00 2001 From: Matheus Ferst Date: Wed, 30 Mar 2022 14:59:26 -0300 Subject: [PATCH] qemu/int128: add int128_urshift Implement an unsigned right shift for Int128 values and add the same tests cases of int128_rshift in the unit test. Signed-off-by: Matheus Ferst Reviewed-by: Richard Henderson Message-Id: <20220330175932.6995-3-matheus.ferst@eldorado.org.br> [danielhb: fixed long lines in test_urshift()] Signed-off-by: Daniel Henrique Barboza --- include/qemu/int128.h | 19 +++++++++++++++ tests/unit/test-int128.c | 50 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+) diff --git a/include/qemu/int128.h b/include/qemu/int128.h index 37e07fd6dd..1f82918c73 100644 --- a/include/qemu/int128.h +++ b/include/qemu/int128.h @@ -83,6 +83,11 @@ static inline Int128 int128_rshift(Int128 a, int n) return a >> n; } +static inline Int128 int128_urshift(Int128 a, int n) +{ + return (__uint128_t)a >> n; +} + static inline Int128 int128_lshift(Int128 a, int n) { return a << n; @@ -299,6 +304,20 @@ static inline Int128 int128_rshift(Int128 a, int n) } } +static inline Int128 int128_urshift(Int128 a, int n) +{ + uint64_t h = a.hi; + if (!n) { + return a; + } + h = h >> (n & 63); + if (n >= 64) { + return int128_make64(h); + } else { + return int128_make128((a.lo >> n) | ((uint64_t)a.hi << (64 - n)), h); + } +} + static inline Int128 int128_lshift(Int128 a, int n) { uint64_t l = a.lo << (n & 63); diff --git a/tests/unit/test-int128.c b/tests/unit/test-int128.c index b86a3c76e6..25db2455e8 100644 --- a/tests/unit/test-int128.c +++ b/tests/unit/test-int128.c @@ -206,6 +206,55 @@ static void test_rshift(void) test_rshift_one(0xFFFE8000U, 0, 0xFFFFFFFFFFFFFFFEULL, 0x8000000000000000ULL); } +static void __attribute__((__noinline__)) ATTRIBUTE_NOCLONE +test_urshift_one(uint32_t x, int n, uint64_t h, uint64_t l) +{ + Int128 a = expand(x); + Int128 r = int128_urshift(a, n); + g_assert_cmpuint(int128_getlo(r), ==, l); + g_assert_cmpuint(int128_gethi(r), ==, h); +} + +static void test_urshift(void) +{ + test_urshift_one(0x00010000U, 64, 0x0000000000000000ULL, + 0x0000000000000001ULL); + test_urshift_one(0x80010000U, 64, 0x0000000000000000ULL, + 0x8000000000000001ULL); + test_urshift_one(0x7FFE0000U, 64, 0x0000000000000000ULL, + 0x7FFFFFFFFFFFFFFEULL); + test_urshift_one(0xFFFE0000U, 64, 0x0000000000000000ULL, + 0xFFFFFFFFFFFFFFFEULL); + test_urshift_one(0x00010000U, 60, 0x0000000000000000ULL, + 0x0000000000000010ULL); + test_urshift_one(0x80010000U, 60, 0x0000000000000008ULL, + 0x0000000000000010ULL); + test_urshift_one(0x00018000U, 60, 0x0000000000000000ULL, + 0x0000000000000018ULL); + test_urshift_one(0x80018000U, 60, 0x0000000000000008ULL, + 0x0000000000000018ULL); + test_urshift_one(0x7FFE0000U, 60, 0x0000000000000007ULL, + 0xFFFFFFFFFFFFFFE0ULL); + test_urshift_one(0xFFFE0000U, 60, 0x000000000000000FULL, + 0xFFFFFFFFFFFFFFE0ULL); + test_urshift_one(0x7FFE8000U, 60, 0x0000000000000007ULL, + 0xFFFFFFFFFFFFFFE8ULL); + test_urshift_one(0xFFFE8000U, 60, 0x000000000000000FULL, + 0xFFFFFFFFFFFFFFE8ULL); + test_urshift_one(0x00018000U, 0, 0x0000000000000001ULL, + 0x8000000000000000ULL); + test_urshift_one(0x80018000U, 0, 0x8000000000000001ULL, + 0x8000000000000000ULL); + test_urshift_one(0x7FFE0000U, 0, 0x7FFFFFFFFFFFFFFEULL, + 0x0000000000000000ULL); + test_urshift_one(0xFFFE0000U, 0, 0xFFFFFFFFFFFFFFFEULL, + 0x0000000000000000ULL); + test_urshift_one(0x7FFE8000U, 0, 0x7FFFFFFFFFFFFFFEULL, + 0x8000000000000000ULL); + test_urshift_one(0xFFFE8000U, 0, 0xFFFFFFFFFFFFFFFEULL, + 0x8000000000000000ULL); +} + int main(int argc, char **argv) { g_test_init(&argc, &argv, NULL); @@ -219,5 +268,6 @@ int main(int argc, char **argv) g_test_add_func("/int128/int128_ge", test_ge); g_test_add_func("/int128/int128_gt", test_gt); g_test_add_func("/int128/int128_rshift", test_rshift); + g_test_add_func("/int128/int128_urshift", test_urshift); return g_test_run(); }