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-rw-r--r--include/qemu/host-utils.h27
-rw-r--r--tests/.gitignore1
-rw-r--r--tests/Makefile.include5
-rw-r--r--tests/test-shift128.c139
-rw-r--r--util/host-utils.c64
5 files changed, 235 insertions, 1 deletions
diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h
index 96288d0bce..a38be42253 100644
--- a/include/qemu/host-utils.h
+++ b/include/qemu/host-utils.h
@@ -513,4 +513,31 @@ static inline uint64_t pow2ceil(uint64_t value)
     return 1ULL << (64 - nlz);
 }
 
+/**
+ * urshift - 128-bit Unsigned Right Shift.
+ * @plow: in/out - lower 64-bit integer.
+ * @phigh: in/out - higher 64-bit integer.
+ * @shift: in - bytes to shift, between 0 and 127.
+ *
+ * Result is zero-extended and stored in plow/phigh, which are
+ * input/output variables. Shift values outside the range will
+ * be mod to 128. In other words, the caller is responsible to
+ * verify/assert both the shift range and plow/phigh pointers.
+ */
+void urshift(uint64_t *plow, uint64_t *phigh, int32_t shift);
+
+/**
+ * ulshift - 128-bit Unsigned Left Shift.
+ * @plow: in/out - lower 64-bit integer.
+ * @phigh: in/out - higher 64-bit integer.
+ * @shift: in - bytes to shift, between 0 and 127.
+ * @overflow: out - true if any 1-bit is shifted out.
+ *
+ * Result is zero-extended and stored in plow/phigh, which are
+ * input/output variables. Shift values outside the range will
+ * be mod to 128. In other words, the caller is responsible to
+ * verify/assert both the shift range and plow/phigh pointers.
+ */
+void ulshift(uint64_t *plow, uint64_t *phigh, int32_t shift, bool *overflow);
+
 #endif
diff --git a/tests/.gitignore b/tests/.gitignore
index 7357d0a0d4..dc37519421 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -69,6 +69,7 @@ test-qmp-marshal.c
 test-qobject-output-visitor
 test-rcu-list
 test-replication
+test-shift128
 test-string-input-visitor
 test-string-output-visitor
 test-thread-pool
diff --git a/tests/Makefile.include b/tests/Makefile.include
index c35fa751f2..1f6b732d13 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)
@@ -487,7 +489,7 @@ 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
 
@@ -596,6 +598,7 @@ 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 $(test-util-obj-y)
 tests/test-bitcnt$(EXESUF): tests/test-bitcnt.o $(test-util-obj-y)
diff --git a/tests/test-shift128.c b/tests/test-shift128.c
new file mode 100644
index 0000000000..f3ff736e5c
--- /dev/null
+++ b/tests/test-shift128.c
@@ -0,0 +1,139 @@
+/*
+ * 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[] = {
+    { 0x4C7ULL, 0x0ULL, 0x00000000000004C7ULL,
+      0x0000000000000000ULL,   0, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000002ULL,
+      0x0000000000000000ULL,   1, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000004ULL,
+      0x0000000000000000ULL,   2, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000010ULL,
+      0x0000000000000000ULL,   4, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000100ULL,
+      0x0000000000000000ULL,   8, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000010000ULL,
+      0x0000000000000000ULL,  16, false },
+    { 0x001ULL, 0x0ULL, 0x0000000080000000ULL,
+      0x0000000000000000ULL,  31, false },
+    { 0x001ULL, 0x0ULL, 0x0000200000000000ULL,
+      0x0000000000000000ULL,  45, false },
+    { 0x001ULL, 0x0ULL, 0x1000000000000000ULL,
+      0x0000000000000000ULL,  60, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x0000000000000001ULL,  64, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x0000000000010000ULL,  80, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x8000000000000000ULL, 127, false },
+    { 0x000ULL, 0x1ULL, 0x0000000000000000ULL,
+      0x0000000000000000ULL,  64,  true },
+    { 0x008ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x0000000000000008ULL,  64, false },
+    { 0x008ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x8000000000000000ULL, 124, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x4000000000000000ULL, 126, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x8000000000000000ULL, 127, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000001ULL,
+      0x0000000000000000ULL, 128,  false },
+    { 0x000ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x0000000000000000ULL, 200, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x0000000000000100ULL, 200,  false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x8000000000000000ULL,  -1, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x8000000000000000ULL, INT32_MAX, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x4000000000000000ULL,  -2, false },
+    { 0x001ULL, 0x0ULL, 0x0000000000000000ULL,
+      0x4000000000000000ULL, INT32_MAX - 1, false },
+    { 0x8888888888888888ULL, 0x9999999999999999ULL,
+      0x8000000000000000ULL, 0x9888888888888888ULL, 60, true },
+    { 0x8888888888888888ULL, 0x9999999999999999ULL,
+      0x0000000000000000ULL, 0x8888888888888888ULL, 64, true },
+};
+
+static const test_data test_rtable[] = {
+    { 0x00000000000004C7ULL, 0x0ULL, 0x00000000000004C7ULL, 0x0ULL,  0, false },
+    { 0x0800000000000000ULL, 0x0ULL, 0x0400000000000000ULL, 0x0ULL,  1, false },
+    { 0x0800000000000000ULL, 0x0ULL, 0x0200000000000000ULL, 0x0ULL,  2, false },
+    { 0x0800000000000000ULL, 0x0ULL, 0x0008000000000000ULL, 0x0ULL,  8, false },
+    { 0x0800000000000000ULL, 0x0ULL, 0x0000080000000000ULL, 0x0ULL, 16, false },
+    { 0x0800000000000000ULL, 0x0ULL, 0x0000000008000000ULL, 0x0ULL, 32, false },
+    { 0x8000000000000000ULL, 0x0ULL, 0x0000000000000001ULL, 0x0ULL, 63, false },
+    { 0x8000000000000000ULL, 0x0ULL, 0x0000000000000000ULL, 0x0ULL, 64, false },
+    { 0x0000000000000000ULL, 0x8000000000000000ULL,
+      0x0000000000000000ULL, 0x8000000000000000ULL, 128, false },
+    { 0x0000000000000000ULL, 0x8000000000000000ULL,
+      0x0080000000000000ULL, 0x0000000000000000ULL, 200, false },
+    { 0x0000000000000000ULL, 0x0000000000000000ULL,
+      0x0000000000000000ULL, 0x0000000000000000ULL, 200, false },
+    { 0x0000000000000000ULL, 0x8000000000000000ULL,
+      0x0000000000000000ULL, 0x0000000000000080ULL, -200, false },
+    { 0x8000000000000000ULL, 0x8000000000000000ULL,
+      0x0000000080000000ULL, 0x0000000080000000ULL, 32, false },
+    { 0x0800000000000000ULL, 0x0800000000000000ULL,
+      0x0800000000000000ULL, 0x0000000000000000ULL, 64, false },
+    { 0x0800000000000000ULL, 0x0800000000000000ULL,
+      0x0008000000000000ULL, 0x0000000000000000ULL, 72, false },
+    { 0x8000000000000000ULL, 0x8000000000000000ULL,
+      0x0000000000000001ULL, 0x0000000000000000ULL, 127, false },
+    { 0x0000000000000000ULL, 0x8000000000000000ULL,
+      0x0000000000000001ULL, 0x0000000000000000ULL, -1, false },
+    { 0x0000000000000000ULL, 0x8000000000000000ULL,
+      0x0000000000000002ULL, 0x0000000000000000ULL, -2, 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, ==, 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 3495262233..7b9322071d 100644
--- a/util/host-utils.c
+++ b/util/host-utils.c
@@ -161,3 +161,67 @@ int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
 }
 #endif
 
+/**
+ * urshift - 128-bit Unsigned Right Shift.
+ * @plow: in/out - lower 64-bit integer.
+ * @phigh: in/out - higher 64-bit integer.
+ * @shift: in - bytes to shift, between 0 and 127.
+ *
+ * Result is zero-extended and stored in plow/phigh, which are
+ * input/output variables. Shift values outside the range will
+ * be mod to 128. In other words, the caller is responsible to
+ * verify/assert both the shift range and plow/phigh pointers.
+ */
+void urshift(uint64_t *plow, uint64_t *phigh, int32_t shift)
+{
+    shift &= 127;
+    if (shift == 0) {
+        return;
+    }
+
+    uint64_t h = *phigh >> (shift & 63);
+    if (shift >= 64) {
+        *plow = h;
+        *phigh = 0;
+    } else {
+        *plow = (*plow >> (shift & 63)) | (*phigh << (64 - (shift & 63)));
+        *phigh = h;
+    }
+}
+
+/**
+ * ulshift - 128-bit Unsigned Left Shift.
+ * @plow: in/out - lower 64-bit integer.
+ * @phigh: in/out - higher 64-bit integer.
+ * @shift: in - bytes to shift, between 0 and 127.
+ * @overflow: out - true if any 1-bit is shifted out.
+ *
+ * Result is zero-extended and stored in plow/phigh, which are
+ * input/output variables. Shift values outside the range will
+ * be mod to 128. In other words, the caller is responsible to
+ * verify/assert both the shift range and plow/phigh pointers.
+ */
+void ulshift(uint64_t *plow, uint64_t *phigh, int32_t shift, bool *overflow)
+{
+    uint64_t low = *plow;
+    uint64_t high = *phigh;
+
+    shift &= 127;
+    if (shift == 0) {
+        return;
+    }
+
+    /* check if any bit will be shifted out */
+    urshift(&low, &high, 128 - shift);
+    if (low | high) {
+        *overflow = true;
+    }
+
+    if (shift >= 64) {
+        *phigh = *plow << (shift & 63);
+        *plow = 0;
+    } else {
+        *phigh = (*plow >> (64 - (shift & 63))) | (*phigh << (shift & 63));
+        *plow = *plow << shift;
+    }
+}