Moved RNG out of the compiler and into a standalone library

1 files changed, 0 insertions, 274 deletions

diff --git a/src/stdlib/rng.c b/src/stdlib/rng.c
deleted file mode 100644
index ffc28084..00000000
--- a/src/stdlib/rng.c
+++ /dev/null
@@ -1,274 +0,0 @@
-// Random Number Generator (RNG) implementation based on ChaCha
-
-#include <ctype.h>
-#include <err.h>
-#include <gc.h>
-#include <gmp.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/param.h>
-
-#include "arrays.h"
-#include "datatypes.h"
-#include "rng.h"
-#include "text.h"
-#include "util.h"
-
-#include "chacha.h"
-
-struct RNGState_t {
-    chacha_ctx chacha;
-    size_t unused_bytes;
-    uint8_t random_bytes[1024];
-};
-
-#ifdef __TINYC__
-// TinyCC doesn't implement _Thread_local
-public RNG_t default_rng = (struct RNGState_t[1]){};
-#else
-public _Thread_local RNG_t default_rng = (struct RNGState_t[1]){};
-#endif
-
-PUREFUNC static Text_t RNG$as_text(const void *rng, bool colorize, const TypeInfo_t*)
-{
-    if (!rng) return Text("RNG");
-    return Text$format(colorize ? "\x1b[34;1mRNG(%p)\x1b[m" : "RNG(%p)", *(RNG_t**)rng);
-}
-
-#define KEYSZ 32
-#define IVSZ 8
-
-public void RNG$set_seed(RNG_t rng, Array_t seed)
-{
-    uint8_t seed_bytes[KEYSZ + IVSZ] = {};
-    for (int64_t i = 0; i < (int64_t)sizeof(seed_bytes); i++)
-        seed_bytes[i] = i < seed.length ? *(uint8_t*)(seed.data + i*seed.stride) : 0;
-
-    rng->unused_bytes = 0;
-    chacha_keysetup(&rng->chacha, seed_bytes, KEYSZ/8);
-    chacha_ivsetup(&rng->chacha, seed_bytes + KEYSZ);
-}
-
-public RNG_t RNG$copy(RNG_t rng)
-{
-    RNG_t copy = GC_MALLOC_ATOMIC(sizeof(struct RNGState_t));
-    *copy = *rng;
-    return copy;
-}
-
-public RNG_t RNG$new(Array_t seed)
-{
-    RNG_t rng = GC_MALLOC_ATOMIC(sizeof(struct RNGState_t));
-    RNG$set_seed(rng, seed);
-    return rng;
-}
-
-static void rekey(RNG_t rng)
-{
-    // Fill the buffer with the keystream
-    chacha_encrypt_bytes(&rng->chacha, rng->random_bytes, rng->random_bytes, sizeof(rng->random_bytes));
-    // Immediately reinitialize for backtracking resistance
-    chacha_keysetup(&rng->chacha, rng->random_bytes, KEYSZ/8);
-    chacha_ivsetup(&rng->chacha, rng->random_bytes + KEYSZ);
-#ifdef __APPLE__
-    bzero(rng->random_bytes, KEYSZ + IVSZ);
-#else
-    explicit_bzero(rng->random_bytes, KEYSZ + IVSZ);
-#endif
-    rng->unused_bytes = sizeof(rng->random_bytes) - KEYSZ - IVSZ;
-    assert(rng->unused_bytes <= sizeof(rng->random_bytes));
-}
-
-static void random_bytes(RNG_t rng, uint8_t *dest, size_t needed)
-{
-    while (needed > 0) {
-        assert(rng->unused_bytes <= sizeof(rng->random_bytes));
-        if (rng->unused_bytes == 0)
-            rekey(rng);
-
-        size_t batch_size = MIN(needed, rng->unused_bytes);
-        uint8_t *batch_src = rng->random_bytes + sizeof(rng->random_bytes) - rng->unused_bytes;
-        memcpy(dest, batch_src, batch_size);
-        memset(batch_src, 0, batch_size);
-        rng->unused_bytes -= batch_size;
-        dest += batch_size;
-        needed -= batch_size;
-        assert(rng->unused_bytes <= sizeof(rng->random_bytes));
-    }
-}
-
-public Bool_t RNG$bool(RNG_t rng, Num_t p)
-{
-    if (p == 0.5) {
-        uint8_t b;
-        random_bytes(rng, &b, sizeof(b));
-        return b & 1;
-    } else {
-        return RNG$num(rng, 0.0, 1.0) < p;
-    }
-}
-
-public Int_t RNG$int(RNG_t rng, Int_t min, Int_t max)
-{
-    if (likely(((min.small & max.small) & 1) != 0)) {
-        int32_t r = RNG$int32(rng, (int32_t)(min.small >> 2), (int32_t)(max.small >> 2));
-        return I_small(r);
-    }
-
-    int32_t cmp = Int$compare_value(min, max);
-    if (cmp > 0)
-        fail("Random minimum value (", min, ") is larger than the maximum value (", max, ")");
-    if (cmp == 0) return min;
-
-    mpz_t range_size;
-    mpz_init_set_int(range_size, max);
-    if (min.small & 1) {
-        mpz_t min_mpz;
-        mpz_init_set_si(min_mpz, min.small >> 2);
-        mpz_sub(range_size, range_size, min_mpz);
-    } else {
-        mpz_sub(range_size, range_size, *min.big);
-    }
-
-    gmp_randstate_t gmp_rng;
-    gmp_randinit_default(gmp_rng);
-    gmp_randseed_ui(gmp_rng, (unsigned long)RNG$int64(rng, INT64_MIN, INT64_MAX));
-
-    mpz_t r;
-    mpz_init(r);
-    mpz_urandomm(r, gmp_rng, range_size);
-
-    gmp_randclear(gmp_rng);
-    return Int$plus(min, Int$from_mpz(r));
-}
-
-public Int64_t RNG$int64(RNG_t rng, Int64_t min, Int64_t max)
-{
-    if (min > max) fail("Random minimum value (", min, ") is larger than the maximum value (", max, ")");
-    if (min == max) return min;
-    if (min == INT64_MIN && max == INT64_MAX) {
-        int64_t r;
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        return r;
-    }
-    uint64_t range = (uint64_t)max - (uint64_t)min + 1;
-    uint64_t min_r = -range % range;
-    uint64_t r;
-    for (;;) {
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        if (r >= min_r) break;
-    }
-    return (int64_t)((uint64_t)min + (r % range));
-}
-
-public Int32_t RNG$int32(RNG_t rng, Int32_t min, Int32_t max)
-{
-    if (min > max) fail("Random minimum value (", min, ") is larger than the maximum value (", max, ")");
-    if (min == max) return min;
-    if (min == INT32_MIN && max == INT32_MAX) {
-        int32_t r;
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        return r;
-    }
-    uint32_t range = (uint32_t)max - (uint32_t)min + 1;
-    uint32_t min_r = -range % range;
-    uint32_t r;
-    for (;;) {
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        if (r >= min_r) break;
-    }
-    return (int32_t)((uint32_t)min + (r % range));
-}
-
-public Int16_t RNG$int16(RNG_t rng, Int16_t min, Int16_t max)
-{
-    if (min > max) fail("Random minimum value (", min, ") is larger than the maximum value (", max, ")");
-    if (min == max) return min;
-    if (min == INT16_MIN && max == INT16_MAX) {
-        int16_t r;
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        return r;
-    }
-    uint16_t range = (uint16_t)max - (uint16_t)min + 1;
-    uint16_t min_r = -range % range;
-    uint16_t r;
-    for (;;) {
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        if (r >= min_r) break;
-    }
-    return (int16_t)((uint16_t)min + (r % range));
-}
-
-public Int8_t RNG$int8(RNG_t rng, Int8_t min, Int8_t max)
-{
-    if (min > max) fail("Random minimum value (", min, ") is larger than the maximum value (", max, ")");
-    if (min == max) return min;
-    if (min == INT8_MIN && max == INT8_MAX) {
-        int8_t r;
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        return r;
-    }
-    uint8_t range = (uint8_t)max - (uint8_t)min + 1;
-    uint8_t min_r = -range % range;
-    uint8_t r;
-    for (;;) {
-        random_bytes(rng, (uint8_t*)&r, sizeof(r));
-        if (r >= min_r) break;
-    }
-    return (int8_t)((uint8_t)min + (r % range));
-}
-
-public Num_t RNG$num(RNG_t rng, Num_t min, Num_t max)
-{
-    if (min > max) fail("Random minimum value (", min, ") is larger than the maximum value (", max, ")");
-    if (min == max) return min;
-
-    union {
-        Num_t num;
-        uint64_t bits;
-    } r = {.bits=0}, one = {.num=1.0};
-    random_bytes(rng, (void*)&r, sizeof(r));
-
-    // Set r.num to 1.<random-bits>
-    r.bits &= ~(0xFFFULL << 52);
-    r.bits |= (one.bits & (0xFFFULL << 52));
-
-    r.num -= 1.0;
-
-    if (min == 0.0 && max == 1.0)
-        return r.num;
-
-    return (1.0-r.num)*min + r.num*max;
-}
-
-public Num32_t RNG$num32(RNG_t rng, Num32_t min, Num32_t max)
-{
-    return (Num32_t)RNG$num(rng, (Num_t)min, (Num_t)max);
-}
-
-public Byte_t RNG$byte(RNG_t rng)
-{
-    Byte_t b;
-    random_bytes(rng, &b, sizeof(b));
-    return b;
-}
-
-public Array_t RNG$bytes(RNG_t rng, Int_t count)
-{
-    int64_t n = Int64$from_int(count, false);
-    Byte_t *r = GC_MALLOC_ATOMIC(sizeof(Byte_t[n]));
-    random_bytes(rng, r, sizeof(Byte_t[n]));
-    return (Array_t){.data=r, .length=n, .stride=1, .atomic=1};
-}
-
-public const TypeInfo_t RNG$info = {
-    .size=sizeof(void*),
-    .align=__alignof__(void*),
-    .metamethods={
-        .as_text=RNG$as_text,
-    },
-};
-
-// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0