This commit implements functions to right and left shifts and the
unittest for them. Such functions is needed due to instructions
that requires them.
Today, there is already a right shift implementation in int128.h
but it's for signed numbers.
Signed-off-by: Jose Ricardo Ziviani <jos...@linux.vnet.ibm.com>
---
include/qemu/host-utils.h | 29 ++++++++++++++
tests/Makefile.include | 5 ++-
tests/test-shift128.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++
util/host-utils.c | 38 +++++++++++++++++++
4 files changed, 168 insertions(+), 1 deletion(-)
create mode 100644 tests/test-shift128.c
diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h
index 46187bb..b3e5f72 100644
--- a/include/qemu/host-utils.h
+++ b/include/qemu/host-utils.h
@@ -29,6 +29,33 @@
#include "qemu/bswap.h"
#ifdef CONFIG_INT128
+static inline void urshift(uint64_t *plow, uint64_t *phigh, uint32_t shift)
+{
+ __uint128_t val = ((__uint128_t)*phigh << 64) | *plow;
+ val >>= (shift & 127);
+ *phigh = val >> 64;
+ *plow = val & 0xffffffffffffffff;
+}
+
+static inline void ulshift(uint64_t *plow, uint64_t *phigh,
+ uint32_t shift, bool *overflow)
+{
+ __uint128_t val = ((__uint128_t)*phigh << 64) | *plow;
+
+ if (shift == 0) {
+ return;
+ }
+
+ if (shift > 127 || (val >> (128 - (shift & 127))) != 0) {
+ *overflow = true;
+ }
+
+ val <<= (shift & 127);
+
+ *phigh = val >> 64;
+ *plow = val & 0xffffffffffffffff;
+}
+
static inline void mulu64(uint64_t *plow, uint64_t *phigh,
uint64_t a, uint64_t b)
{
@@ -81,6 +108,8 @@ void muls64(uint64_t *phigh, uint64_t *plow, int64_t a,
int64_t b);
void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b);
int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor);
int divs128(int64_t *plow, int64_t *phigh, int64_t divisor);
+void urshift(uint64_t *plow, uint64_t *phigh, uint32_t shift);
+void ulshift(uint64_t *plow, uint64_t *phigh, uint32_t shift, bool *overflow);
static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
{
diff --git a/tests/Makefile.include b/tests/Makefile.include
index e98d3b6..89e5e85 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -65,6 +65,8 @@ check-unit-$(CONFIG_POSIX) += tests/test-vmstate$(EXESUF)
endif
check-unit-y += tests/test-cutils$(EXESUF)
gcov-files-test-cutils-y += util/cutils.c
+check-unit-y += tests/test-shift128$(EXESUF)
+gcov-files-test-shift128-y = util/host-utils.c
check-unit-y += tests/test-mul64$(EXESUF)
gcov-files-test-mul64-y = util/host-utils.c
check-unit-y += tests/test-int128$(EXESUF)
@@ -460,7 +462,7 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o
tests/check-qdict.o \
tests/test-x86-cpuid.o tests/test-mul64.o tests/test-int128.o \
tests/test-opts-visitor.o tests/test-qmp-event.o \
tests/rcutorture.o tests/test-rcu-list.o \
- tests/test-qdist.o \
+ tests/test-qdist.o tests/test-shift128.o \
tests/test-qht.o tests/qht-bench.o tests/test-qht-par.o \
tests/atomic_add-bench.o
@@ -568,6 +570,7 @@ tests/test-qmp-commands$(EXESUF): tests/test-qmp-commands.o
tests/test-qmp-marsh
tests/test-visitor-serialization$(EXESUF): tests/test-visitor-serialization.o
$(test-qapi-obj-y)
tests/test-opts-visitor$(EXESUF): tests/test-opts-visitor.o $(test-qapi-obj-y)
+tests/test-shift128$(EXESUF): tests/test-shift128.o $(test-util-obj-y)
tests/test-mul64$(EXESUF): tests/test-mul64.o $(test-util-obj-y)
tests/test-bitops$(EXESUF): tests/test-bitops.o $(test-util-obj-y)
tests/test-crypto-hash$(EXESUF): tests/test-crypto-hash.o $(test-crypto-obj-y)
diff --git a/tests/test-shift128.c b/tests/test-shift128.c
new file mode 100644
index 0000000..67615c9
--- /dev/null
+++ b/tests/test-shift128.c
@@ -0,0 +1,97 @@
+/*
+ * Test unsigned left and right shift
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/host-utils.h"
+
+typedef struct {
+ uint64_t low;
+ uint64_t high;
+ uint64_t rlow;
+ uint64_t rhigh;
+ int32_t shift;
+ bool overflow;
+} test_data;
+
+static const test_data test_ltable[] = {
+ { 1223ULL, 0, 1223ULL, 0, 0, false },
+ { 1ULL, 0, 2ULL, 0, 1, false },
+ { 1ULL, 0, 4ULL, 0, 2, false },
+ { 1ULL, 0, 16ULL, 0, 4, false },
+ { 1ULL, 0, 256ULL, 0, 8, false },
+ { 1ULL, 0, 65536ULL, 0, 16, false },
+ { 1ULL, 0, 2147483648ULL, 0, 31, false },
+ { 1ULL, 0, 35184372088832ULL, 0, 45, false },
+ { 1ULL, 0, 1152921504606846976ULL, 0, 60, false },
+ { 1ULL, 0, 0, 1ULL, 64, false },
+ { 1ULL, 0, 0, 65536ULL, 80, false },
+ { 1ULL, 0, 0, 9223372036854775808ULL, 127, false },
+ { 0ULL, 1, 0, 0, 64, true },
+ { 0x8888888888888888ULL, 0x9999999999999999ULL,
+ 0x8000000000000000ULL, 0x9888888888888888ULL, 60, true },
+ { 0x8888888888888888ULL, 0x9999999999999999ULL,
+ 0, 0x8888888888888888ULL, 64, true },
+ { 0x8ULL, 0, 0, 0x8ULL, 64, false },
+ { 0x8ULL, 0, 0, 0x8000000000000000ULL, 124, false },
+ { 0x1ULL, 0, 0, 0x4000000000000000ULL, 126, false },
+ { 0x1ULL, 0, 0, 0x8000000000000000ULL, 127, false },
+ { 0x1ULL, 0, 0x1ULL, 0, 128, true },
+};
+
+static const test_data test_rtable[] = {
+ { 1223ULL, 0, 1223ULL, 0, 0, false },
+ { 9223372036854775808ULL, 9223372036854775808ULL,
+ 2147483648L, 2147483648ULL, 32, false },
+ { 9223372036854775808ULL, 9223372036854775808ULL,
+ 9223372036854775808ULL, 0, 64, false },
+ { 9223372036854775808ULL, 9223372036854775808ULL,
+ 36028797018963968ULL, 0, 72, false },
+ { 9223372036854775808ULL, 9223372036854775808ULL,
+ 1ULL, 0, 127, false },
+ { 9223372036854775808ULL, 0, 4611686018427387904ULL, 0, 1, false },
+ { 9223372036854775808ULL, 0, 2305843009213693952ULL, 0, 2, false },
+ { 9223372036854775808ULL, 0, 36028797018963968ULL, 0, 8, false },
+ { 9223372036854775808ULL, 0, 140737488355328ULL, 0, 16, false },
+ { 9223372036854775808ULL, 0, 2147483648ULL, 0, 32, false },
+ { 9223372036854775808ULL, 0, 1ULL, 0, 63, false },
+ { 9223372036854775808ULL, 0, 0ULL, 0, 64, false },
+};
+
+static void test_lshift(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(test_ltable); ++i) {
+ bool overflow = false;
+ test_data tmp = test_ltable[i];
+ ulshift(&tmp.low, &tmp.high, tmp.shift, &overflow);
+ g_assert_cmpuint(tmp.low, ==, tmp.rlow);
+ g_assert_cmpuint(tmp.high, ==, tmp.rhigh);
+ g_assert_cmpuint(tmp.overflow, ==, tmp.overflow);
+ }
+}
+
+static void test_rshift(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(test_rtable); ++i) {
+ test_data tmp = test_rtable[i];
+ urshift(&tmp.low, &tmp.high, tmp.shift);
+ g_assert_cmpuint(tmp.low, ==, tmp.rlow);
+ g_assert_cmpuint(tmp.high, ==, tmp.rhigh);
+ }
+}
+
+int main(int argc, char **argv)
+{
+ g_test_init(&argc, &argv, NULL);
+ g_test_add_func("/host-utils/test_lshift", test_lshift);
+ g_test_add_func("/host-utils/test_rshift", test_rshift);
+ return g_test_run();
+}
diff --git a/util/host-utils.c b/util/host-utils.c
index b166e57..7a97397 100644
--- a/util/host-utils.c
+++ b/util/host-utils.c
@@ -159,3 +159,41 @@ int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
return overflow;
}
+void urshift(uint64_t *plow, uint64_t *phigh, uint32_t shift)
+{
+ uint64_t h = *phigh >> (shift & 63);
+ if (shift == 0) {
+ return;
+ } else if (shift >= 64) {
+ *plow = h;
+ *phigh = 0;
+ } else {
+ *plow = (*plow >> (shift & 63)) | (*phigh << (64 - (shift & 63)));
+ *phigh = h;
+ }
+}
+
+void ulshift(uint64_t *plow, uint64_t *phigh, uint32_t shift, bool *overflow)
+{
+ uint64_t low = *plow;
+ uint64_t high = *phigh;
+ shift &= 127;
+
+ if (shift == 0) {
+ return;
+ }
+
+ urshift(&low, &high, 128 - (shift & 127));
+
+ if (shift > 127 || low > 0 || high > 0) {
+ *overflow = true;
+ }
+
+ if (shift >= 64) {
+ *phigh = *plow << (shift & 63);
+ *plow = 0;
+ } else {
+ *phigh = (*plow >> (64 - (shift & 63))) | (*phigh << (shift & 63));
+ *plow = *plow << shift;
+ }
+}
--
2.7.4
