From 9831e26f4fbe99d464accf4bcdbab740677874ca Mon Sep 17 00:00:00 2001
From: Thor Harald Johansen <thj@thj.no>
Date: Thu, 21 May 2020 17:06:12 +0200
Subject: [PATCH] Initial commit

---
 .gitignore |   1 +
 prand.c    |  32 +++++++++++++
 rand.h     | 129 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 162 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 prand.c
 create mode 100644 rand.h

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..50d50f0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+prand
diff --git a/prand.c b/prand.c
new file mode 100644
index 0000000..625be75
--- /dev/null
+++ b/prand.c
@@ -0,0 +1,32 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#include "rand.h"
+
+#define BUF_SIZE (16 * 1024 * 1024)
+
+int main(int argc, char** argv) {
+    unsigned long long init[4]={0x12345ULL, 0x23456ULL, 0x34567ULL, 0x45678ULL}, length=4;
+    init_by_array64(init, length);
+ 
+    uint8_t* buffer = malloc(BUF_SIZE);
+    uint64_t counter = 0;
+
+    for(;;) {
+        for(uint64_t i = 0; i < BUF_SIZE; i += 8) {
+            uint64_t r = genrand64_int64();
+            *((uint64_t*) &buffer[i]) = r;
+        }
+
+        fwrite(buffer, BUF_SIZE, 1, stdout);
+        
+        counter += BUF_SIZE;
+
+        if((counter & 1073741823) == 0) {
+            fprintf(stderr, "Wrote %lld GiB\n", counter / 1073741824);
+        }
+    }
+
+    return 0;
+}
diff --git a/rand.h b/rand.h
new file mode 100644
index 0000000..71a3e7e
--- /dev/null
+++ b/rand.h
@@ -0,0 +1,129 @@
+#include <stdio.h>
+
+#define NN 312
+#define MM 156
+#define MATRIX_A 0xB5026F5AA96619E9ULL
+#define UM 0xFFFFFFFF80000000ULL /* Most significant 33 bits */
+#define LM 0x7FFFFFFFULL /* Least significant 31 bits */
+
+/* The array for the state vector */
+static unsigned long long mt[NN]; 
+/* mti==NN+1 means mt[NN] is not initialized */
+static int mti=NN+1; 
+
+/* initializes mt[NN] with a seed */
+void init_genrand64(unsigned long long seed)
+{
+    mt[0] = seed;
+    for (mti=1; mti<NN; mti++) 
+        mt[mti] =  (6364136223846793005ULL * (mt[mti-1] ^ (mt[mti-1] >> 62)) + mti);
+}
+
+/* initialize by an array with array-length */
+/* init_key is the array for initializing keys */
+/* key_length is its length */
+void init_by_array64(unsigned long long init_key[],
+		     unsigned long long key_length)
+{
+    unsigned long long i, j, k;
+    init_genrand64(19650218ULL);
+    i=1; j=0;
+    k = (NN>key_length ? NN : key_length);
+    for (; k; k--) {
+        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 62)) * 3935559000370003845ULL))
+          + init_key[j] + j; /* non linear */
+        i++; j++;
+        if (i>=NN) { mt[0] = mt[NN-1]; i=1; }
+        if (j>=key_length) j=0;
+    }
+    for (k=NN-1; k; k--) {
+        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 62)) * 2862933555777941757ULL))
+          - i; /* non linear */
+        i++;
+        if (i>=NN) { mt[0] = mt[NN-1]; i=1; }
+    }
+
+    mt[0] = 1ULL << 63; /* MSB is 1; assuring non-zero initial array */ 
+}
+
+/* generates a random number on [0, 2^64-1]-interval */
+unsigned long long genrand64_int64(void)
+{
+    int i;
+    unsigned long long x;
+    static unsigned long long mag01[2]={0ULL, MATRIX_A};
+
+    if (mti >= NN) { /* generate NN words at one time */
+
+        /* if init_genrand64() has not been called, */
+        /* a default initial seed is used     */
+        if (mti == NN+1) 
+            init_genrand64(5489ULL); 
+
+        for (i=0;i<NN-MM;i++) {
+            x = (mt[i]&UM)|(mt[i+1]&LM);
+            mt[i] = mt[i+MM] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
+        }
+        for (;i<NN-1;i++) {
+            x = (mt[i]&UM)|(mt[i+1]&LM);
+            mt[i] = mt[i+(MM-NN)] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
+        }
+        x = (mt[NN-1]&UM)|(mt[0]&LM);
+        mt[NN-1] = mt[MM-1] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
+
+        mti = 0;
+    }
+  
+    x = mt[mti++];
+
+    x ^= (x >> 29) & 0x5555555555555555ULL;
+    x ^= (x << 17) & 0x71D67FFFEDA60000ULL;
+    x ^= (x << 37) & 0xFFF7EEE000000000ULL;
+    x ^= (x >> 43);
+
+    return x;
+}
+
+/* generates a random number on [0, 2^63-1]-interval */
+long long genrand64_int63(void)
+{
+    return (long long)(genrand64_int64() >> 1);
+}
+
+/* generates a random number on [0,1]-real-interval */
+double genrand64_real1(void)
+{
+    return (genrand64_int64() >> 11) * (1.0/9007199254740991.0);
+}
+
+/* generates a random number on [0,1)-real-interval */
+double genrand64_real2(void)
+{
+    return (genrand64_int64() >> 11) * (1.0/9007199254740992.0);
+}
+
+/* generates a random number on (0,1)-real-interval */
+double genrand64_real3(void)
+{
+    return ((genrand64_int64() >> 12) + 0.5) * (1.0/4503599627370496.0);
+}
+
+/*
+int main(void)
+{
+    int i;
+    unsigned long long init[4]={0x12345ULL, 0x23456ULL, 0x34567ULL, 0x45678ULL}, length=4;
+    init_by_array64(init, length);
+    printf("1000 outputs of genrand64_int64()\n");
+    for (i=0; i<1000; i++) {
+      printf("%20llu ", genrand64_int64());
+      if (i%5==4) printf("\n");
+    }
+    printf("\n1000 outputs of genrand64_real2()\n");
+    for (i=0; i<1000; i++) {
+      printf("%10.8f ", genrand64_real2());
+      if (i%5==4) printf("\n");
+    }
+    return 0;
+}
+*/