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Posted to commits@nuttx.apache.org by xi...@apache.org on 2023/01/04 12:53:11 UTC
[nuttx] branch master updated: stdlib: generate uniformly distributed pseudo-random numbers
This is an automated email from the ASF dual-hosted git repository.
xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new c623ee20f1 stdlib: generate uniformly distributed pseudo-random numbers
c623ee20f1 is described below
commit c623ee20f1539e940ea9cb0c929d391d9967da84
Author: Jiuzhu Dong <do...@xiaomi.com>
AuthorDate: Tue Dec 21 22:48:02 2021 +0800
stdlib: generate uniformly distributed pseudo-random numbers
Signed-off-by: dongjiuzhu1 <do...@xiaomi.com>
---
include/stdlib.h | 13 +++
libs/libc/stdlib/Make.defs | 2 +-
libs/libc/stdlib/lib_rand48.c | 202 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 216 insertions(+), 1 deletion(-)
diff --git a/include/stdlib.h b/include/stdlib.h
index a915e407ce..a522680a65 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -132,6 +132,19 @@ extern "C"
void srand(unsigned int seed);
int rand(void);
+void lcong48(FAR unsigned short int param[7]);
+FAR unsigned short int *seed48(FAR unsigned short int seed16v[3]);
+void srand48(long int seedval);
+#ifdef CONFIG_HAVE_LONG_LONG
+long int jrand48(FAR unsigned short int xsubi[3]);
+long int lrand48(void);
+long int mrand48(void);
+long int nrand48(FAR unsigned short int xsubi[3]);
+# ifdef CONFIG_HAVE_DOUBLE
+double drand48(void);
+double erand48(FAR unsigned short int xsubi[3]);
+# endif
+#endif
#define srandom(s) srand(s)
long random(void);
diff --git a/libs/libc/stdlib/Make.defs b/libs/libc/stdlib/Make.defs
index d495a98a05..2692f315d6 100644
--- a/libs/libc/stdlib/Make.defs
+++ b/libs/libc/stdlib/Make.defs
@@ -23,7 +23,7 @@
CSRCS += lib_abs.c lib_abort.c lib_atof.c lib_atoi.c lib_getprogname.c
CSRCS += lib_atol.c lib_atoll.c lib_div.c lib_ldiv.c lib_lldiv.c lib_exit.c
CSRCS += lib_itoa.c lib_labs.c lib_llabs.c lib_realpath.c lib_bsearch.c
-CSRCS += lib_rand.c lib_qsort.c lib_srand.c lib_strtol.c
+CSRCS += lib_rand.c lib_rand48.c lib_qsort.c lib_srand.c lib_strtol.c
CSRCS += lib_strtoll.c lib_strtoul.c lib_strtoull.c lib_strtod.c lib_strtof.c
CSRCS += lib_strtold.c lib_checkbase.c lib_mktemp.c lib_mkstemp.c lib_mkdtemp.c
CSRCS += lib_aligned_alloc.c lib_posix_memalign.c lib_valloc.c lib_mblen.c
diff --git a/libs/libc/stdlib/lib_rand48.c b/libs/libc/stdlib/lib_rand48.c
new file mode 100644
index 0000000000..5d083d06aa
--- /dev/null
+++ b/libs/libc/stdlib/lib_rand48.c
@@ -0,0 +1,202 @@
+/****************************************************************************
+ * libs/libc/stdlib/lib_rand48.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdlib.h>
+
+#include <nuttx/lib/lib.h>
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static unsigned short int g_seed48[7] =
+{
+ 0,
+ 0,
+ 0,
+ 0xe66d,
+ 0xdeec,
+ 0x5,
+ 0xb
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+#ifdef CONFIG_HAVE_LONG_LONG
+static uint64_t rand48_step(FAR unsigned short int *xi,
+ FAR unsigned short int *lc)
+{
+ uint64_t a;
+ uint64_t x;
+
+ x = xi[0] | ((xi[1] + 0ul) << 16) | ((xi[2] + 0ull) << 32);
+ a = lc[0] | ((lc[1] + 0ul) << 16) | ((lc[2] + 0ull) << 32);
+ x = a * x + lc[3];
+
+ xi[0] = x;
+ xi[1] = x >> 16;
+ xi[2] = x >> 32;
+ return x & 0xffffffffffffull;
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: srand48
+ ****************************************************************************/
+
+void srand48(long seed)
+{
+ unsigned short int p[3];
+
+ p[0] = 0x330e;
+ p[1] = seed;
+ p[2] = seed >> 16;
+ seed48(p);
+}
+
+/****************************************************************************
+ * Name: seed48
+ ****************************************************************************/
+
+FAR unsigned short int *seed48(FAR unsigned short int seed16v[3])
+{
+ static unsigned short int p[3];
+
+ memcpy(p, g_seed48, sizeof(p));
+ memcpy(g_seed48, seed16v, sizeof(p));
+ return p;
+}
+
+/****************************************************************************
+ * Name: lcong48
+ ****************************************************************************/
+
+void lcong48(FAR unsigned short int p[7])
+{
+ memcpy(g_seed48, p, sizeof(g_seed48));
+}
+
+/****************************************************************************
+ * Name: jrand48
+ *
+ * Description:
+ * Return signed long integers uniformly distributed over the
+ * interval [-2^31, 2^31).
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_HAVE_LONG_LONG
+long jrand48(FAR unsigned short int s[3])
+{
+ return (long)(rand48_step(s, g_seed48 + 3) >> 16);
+}
+
+/****************************************************************************
+ * Name: mrand48
+ *
+ * Description:
+ * Return signed long integers uniformly distributed over the
+ * interval [-2^31, 2^31).
+ *
+ ****************************************************************************/
+
+long mrand48(void)
+{
+ return jrand48(g_seed48);
+}
+
+/****************************************************************************
+ * Name: nrand48
+ *
+ * Description:
+ * Return nonnegative long integers uniformly distributed over the
+ * interval [0, 2^31).
+ *
+ ****************************************************************************/
+
+long nrand48(FAR unsigned short int s[3])
+{
+ return rand48_step(s, g_seed48 + 3) >> 17;
+}
+
+/****************************************************************************
+ * Name: lrand48
+ *
+ * Description:
+ * Return nonnegative long integers uniformly distributed over the
+ * interval [0, 2^31).
+ *
+ ****************************************************************************/
+
+long lrand48(void)
+{
+ return nrand48(g_seed48);
+}
+
+/****************************************************************************
+ * Name: erand48
+ *
+ * Description:
+ * Return nonnegative double-precision floating-point values uniformly
+ * distributed over the interval [0.0, 1.0).
+ *
+ ****************************************************************************/
+
+# ifdef CONFIG_HAVE_DOUBLE
+double erand48(FAR unsigned short int s[3])
+{
+ union
+ {
+ uint64_t u;
+ double f;
+ } x;
+
+ x.u = 0x3ff0000000000000ull | rand48_step(s, g_seed48 + 3) << 4;
+ return x.f - 1.0;
+}
+
+/****************************************************************************
+ * Name: drand48
+ *
+ * Description:
+ * Return nonnegative double-precision floating-point values uniformly
+ * distributed over the interval [0.0, 1.0).
+ *
+ ****************************************************************************/
+
+double drand48(void)
+{
+ return erand48(g_seed48);
+}
+# endif
+#endif