Some minor touches.

4 files changed, 14 insertions, 18 deletions

diff --git a/README.md b/README.md
index 61c814fb..e6dc7a34 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
-STC - Standard Template library for C

-=====================================

+STC - Standard Template Containers for C99

+==========================================

 

 Introduction

 ------------

diff --git a/benchmarks/crand_benchmark.cpp b/benchmarks/crand_benchmark.cpp
index 70a3bb45..3d42c62b 100644
--- a/benchmarks/crand_benchmark.cpp
+++ b/benchmarks/crand_benchmark.cpp
@@ -84,7 +84,7 @@ using namespace std;
 

 int main(void)

 {

-  enum {N = 1000000000};

+  enum {N = 800000000};

   uint64_t* recipient = new uint64_t[N];

   static stc64_t rng;

   init_state(rng.state, 12345123);

@@ -115,7 +115,7 @@ int main(void)
     for (size_t i = 0; i < N; i++)

       recipient[i] = stc64_rand(&rng);

     end = clock();

-    cout << "stc-crand:\t"

+    cout << "stc64:\t\t"

          << (float(end - beg) / CLOCKS_PER_SEC)

          << " s: " << recipient[312] << endl;

 

@@ -160,7 +160,7 @@ int main(void)
     for (size_t i = 0; i < N; i++)

       s += stc64_rand(&rng);

     end = clock();

-    cout << "stc-crand:\t"

+    cout << "stc64:\t\t"

          << ((float) end - beg) / CLOCKS_PER_SEC

          << " s: " << s << endl;

 

diff --git a/docs/cdeq_api.md b/docs/cdeq_api.md
index 9f72406f..259d02b1 100644
--- a/docs/cdeq_api.md
+++ b/docs/cdeq_api.md
@@ -37,10 +37,6 @@ using_cdeq(str, cstr_t, cstr_del, cstr_compare_raw, const char*, cstr_to_raw, cs
 | Name                       | Purpose              |
 |:---------------------------|:---------------------|
 |  `cdeq_inits`              | Initializer constant |
-|  `cdeq_empty(vec)`         | true if vec is empty |
-|  `cdeq_size(vec)`          | return vec length    |
-|  `cdeq_capacity(vec)`      | return vec capacity  |
-
 
 ## Header file
 
diff --git a/stc/crand.h b/stc/crand.h
index d58c0681..3d010eb2 100644
--- a/stc/crand.h
+++ b/stc/crand.h
@@ -49,29 +49,28 @@ typedef struct {double lower, range;}                      stc64_uniformf_t;
 typedef struct {double mean, stddev, next; bool has_next;} stc64_normalf_t;

 

 

-/* int random number generator, range [0, 2^64). PRNG copyright Tyge Løvset, NORCE Research, 2020 */

+/* Stc64: random number generator, range [0, 2^64). PRNG copyright Tyge Løvset, NORCE Research, 2020 */

 STC_API stc64_t stc64_init(uint64_t seed);

 STC_API stc64_t stc64_with_seq(uint64_t seed, uint64_t seq);

 

 STC_INLINE uint64_t stc64_rand(stc64_t* rng) {

-    enum {LROT = 24, RSHIFT = 11, LSHIFT = 3};

     uint64_t *s = rng->state;

     const uint64_t b = s[1], result = s[0] ^ (s[2] += s[3]|1);

-    s[0] = (b + (b << LSHIFT)) ^ (b >> RSHIFT);

-    s[1] = ((b << LROT) | (b >> (64 - LROT))) + result;

+    s[0] = (b + (b << 3)) ^ (b >> 11);

+    s[1] = ((b << 24) | (b >> (64 - 24))) + result;

     return result;

 }

 

-/* double random number in range [low, high). */

+/* Float64 random number in range [low, high). */

 STC_INLINE double stc64_randf(stc64_t* rng) {

     union {uint64_t i; double f;} u = {0x3FF0000000000000ull | (stc64_rand(rng) >> 12)};

     return u.f - 1.0;

 }

 

-/* integer uniform distributed RNG, range [low, high]. */

+/* Int64 uniform distributed RNG, range [low, high]. */

 STC_API stc64_uniform_t stc64_uniform_init(int64_t low, int64_t high);

 

-/* double uniform distributed RNG, range [low, high). */

+/* Float64 uniform distributed RNG, range [low, high). */

 STC_INLINE stc64_uniformf_t stc64_uniformf_init(double low, double high) {

     stc64_uniformf_t dist = {low, high - low}; return dist;

 }

@@ -92,13 +91,14 @@ STC_INLINE double stc64_uniformf(stc64_t* rng, stc64_uniformf_t* dist) {
                           : [lhs] "0" (a), [rhs] "rm" (b))

 #endif

 

+/* Unbiased bounded uniform distribution. */

 STC_INLINE int64_t stc64_uniform(stc64_t* rng, stc64_uniform_t* d) {

     uint64_t lo, hi;

     do { cmul128(stc64_rand(rng), d->range, &lo, &hi); } while (lo < d->threshold);

     return d->lower + hi;

 }

 

-/* double normal distributed RNG. */

+/* Normal distributed RNG, Float64. */

 STC_INLINE stc64_normalf_t stc64_normalf_init(double mean, double stddev) {

     stc64_normalf_t dist = {mean, stddev, 0.0, false}; return dist;

 }

@@ -109,7 +109,7 @@ STC_API double stc64_normalf(stc64_t* rng, stc64_normalf_t* dist);
 

 /* PRNG crand: by Tyge Løvset, NORCE Research, 2020.

  * Extremely fast PRNG suited for parallel usage with Weyl-sequence parameter.

- * Faster than sfc64, wyhash64, and almost 50% faster than xoshiro256** on gcc.

+ * Faster than sfc64, wyhash64, and xoshiro256** on most platforms.

  * 256bit state, updates only 192bit per rng.

  * 2^63 unique threads with a minimum 2^64 period lengths each.

  * 2^127 minimum period length for single thread (double loop).