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improve PRNG function generator macro (testing with PractRand)
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@boazsegev
boazsegev committed Feb 18, 2025
1 parent 3046701 commit dacc46a
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81 changes: 53 additions & 28 deletions fio-stl.h
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Original file line number Diff line number Diff line change
Expand Up @@ -3285,48 +3285,72 @@ Defining a Pseudo-Random Number Generator Function (deterministic / not)
* https://espadrine.github.io/blog/posts/shishua-the-fastest-prng-in-the-world.html
*/
#define FIO_DEFINE_RANDOM_FUNCTION(extern, name, reseed_log, seed_offset) \
static fio_u256 name##___state = { \
.u64 = {(FIO_U64_HASH_PRIME0 + seed_offset), \
(FIO_U64_HASH_PRIME1 + seed_offset), \
(FIO_U64_HASH_PRIME2 + seed_offset), \
(FIO_U64_HASH_PRIME3 + seed_offset)}}; \
FIO_SFUNC void name##___state_reseed(fio_u256 *state) { \
const size_t jitter_samples = 16 | (state->u8[0] & 15); \
static uint64_t name##___state[4] = {0x9c65875be1fce7b9ULL, \
0x7cc568e838f6a40dULL, \
0x4bb8d885a0fe47d5ULL, \
0x95561f0927ad7ecdULL}; \
FIO_SFUNC void name##___state_reseed(uint64_t *state) { \
const size_t jitter_samples = 8 | (state[0] & 15); \
for (size_t i = 0; i < jitter_samples; ++i) { \
struct timespec t; \
clock_gettime(CLOCK_MONOTONIC, &t); \
FIO_MATH_UXXX_SUFFLE(state[0], 32, 3, 4, 5, 6, 7, 0, 1, 2); \
uint64_t clk[2]; \
clk[0] = (uint64_t)((t.tv_sec << 30) + (int64_t)t.tv_nsec); \
clk[0] = fio_math_mulc64(clk[0], FIO_U64_HASH_PRIME0, clk + 1); \
state->u64[0] += clk[0]; \
state->u64[1] += clk[1]; \
state->u64[2] += clk[0]; \
state->u64[3] += clk[1]; \
clk[1] += FIO_U64_HASH_PRIME0; \
clk[0] += fio_lrot64(clk[0], 27); \
clk[0] += fio_lrot64(clk[0], 49); \
clk[1] += fio_lrot64(clk[1], 27); \
clk[1] += fio_lrot64(clk[1], 49); \
state[0] += clk[0]; \
state[1] += clk[1]; \
state[2] += clk[0]; \
state[3] += clk[1]; \
} \
} \
/** Returns a 128 bit pseudo-random number. */ \
FIO_IFUNC fio_u128 name##128(void) { \
fio_u256 r, t; \
FIO_IFUNC fio_u128 name##___rand(void) { \
fio_u256 r; \
if (reseed_log && reseed_log < 32) { \
static size_t counter; \
if (!((counter++) & ((1ULL << reseed_log) - 1))) \
name##___state_reseed(&name##___state); \
name##___state_reseed(name##___state); \
} \
t = name##___state; \
r.u64[0] = fio_math_mulc64(t.u64[0], FIO_U64_HASH_PRIME0, r.u64 + 1); \
r.u64[2] = fio_math_mulc64(t.u64[2], FIO_U64_HASH_PRIME1, r.u64 + 3); \
/* rotate 256 bit state by 96 bits and add */ \
FIO_MATH_UXXX_SUFFLE(t, 32, 3, 4, 5, 6, 7, 0, 1, 2); \
FIO_MATH_UXXX_OP(r, r, t, 32, +); \
name##___state = r; \
r.u64[0] ^= r.u64[2]; \
r.u64[1] ^= r.u64[3]; \
uint64_t s1[4]; \
{ /* load state to registers and roll, mul, add */ \
const uint64_t s0[] = {name##___state[0], \
name##___state[1], \
name##___state[2], \
name##___state[3]}; \
const uint64_t mulp[] = {0x37701261ED6C16C7ULL, \
0x764DBBB75F3B3E0DULL, \
~(0x37701261ED6C16C7ULL), \
~(0x764DBBB75F3B3E0DULL)}; \
const uint64_t addc[] = {FIO_U64_HASH_PRIME0, \
FIO_U64_HASH_PRIME1, \
FIO_U64_HASH_PRIME2, \
FIO_U64_HASH_PRIME3}; \
for (size_t i = 0; i < 4; ++i) { \
s1[i] = fio_lrot64(s0[i], 33); \
s1[i] += addc[i]; \
s1[i] *= mulp[i]; \
s1[i] += s0[i]; \
} \
} \
for (size_t i = 0; i < 4; ++i) /* store to memory */ \
name##___state[i] = s1[i]; \
{ \
const uint8_t rotc[] = {31, 29, 27, 30}; \
for (size_t i = 0; i < 4; ++i) \
r.u64[i] = fio_lrot64(s1[i], rotc[i]); \
} \
r.u64[0] += r.u64[2]; \
r.u64[1] += r.u64[3]; \
return r.u128[0]; \
} \
/** Returns a 64 bit pseudo-random number. */ \
extern uint64_t name##64(void) { \
fio_u128 r = name##128(); \
fio_u128 r = name##___rand(); \
return r.u64[0]; \
} \
/** Fills the `dest` buffer with pseudo-random noise. */ \
Expand All @@ -3335,12 +3359,12 @@ Defining a Pseudo-Random Number Generator Function (deterministic / not)
return; \
uint8_t *d = (uint8_t *)dest; \
for (unsigned i = 15; i < len; i += 16) { \
fio_u128 r = name##128(); \
fio_u128 r = name##___rand(); \
fio_memcpy16(d, r.u8); \
d += 16; \
} \
if (len & 15) { \
fio_u128 r = name##128(); \
fio_u128 r = name##___rand(); \
fio_memcpy15x(d, r.u8, len); \
} \
}
Expand Down Expand Up @@ -7536,10 +7560,11 @@ SFUNC uint64_t fio_rand64(void) {
/* re-seed state every 4095 requests / 2^12-1 attempts */
fio_rand_reseed();
}
/* load to registers */
const uint64_t s0[] = {fio___rand_state[0],
fio___rand_state[1],
fio___rand_state[2],
fio___rand_state[3]}; /* load to registers */
fio___rand_state[3]};
uint64_t s1[4] = {0};
{
const uint64_t mulp[] = {0x37701261ED6C16C7ULL,
Expand Down
78 changes: 51 additions & 27 deletions fio-stl/000 core.h
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Original file line number Diff line number Diff line change
Expand Up @@ -3248,48 +3248,72 @@ Defining a Pseudo-Random Number Generator Function (deterministic / not)
* https://espadrine.github.io/blog/posts/shishua-the-fastest-prng-in-the-world.html
*/
#define FIO_DEFINE_RANDOM_FUNCTION(extern, name, reseed_log, seed_offset) \
static fio_u256 name##___state = { \
.u64 = {(FIO_U64_HASH_PRIME0 + seed_offset), \
(FIO_U64_HASH_PRIME1 + seed_offset), \
(FIO_U64_HASH_PRIME2 + seed_offset), \
(FIO_U64_HASH_PRIME3 + seed_offset)}}; \
FIO_SFUNC void name##___state_reseed(fio_u256 *state) { \
const size_t jitter_samples = 16 | (state->u8[0] & 15); \
static uint64_t name##___state[4] = {0x9c65875be1fce7b9ULL, \
0x7cc568e838f6a40dULL, \
0x4bb8d885a0fe47d5ULL, \
0x95561f0927ad7ecdULL}; \
FIO_SFUNC void name##___state_reseed(uint64_t *state) { \
const size_t jitter_samples = 8 | (state[0] & 15); \
for (size_t i = 0; i < jitter_samples; ++i) { \
struct timespec t; \
clock_gettime(CLOCK_MONOTONIC, &t); \
FIO_MATH_UXXX_SUFFLE(state[0], 32, 3, 4, 5, 6, 7, 0, 1, 2); \
uint64_t clk[2]; \
clk[0] = (uint64_t)((t.tv_sec << 30) + (int64_t)t.tv_nsec); \
clk[0] = fio_math_mulc64(clk[0], FIO_U64_HASH_PRIME0, clk + 1); \
state->u64[0] += clk[0]; \
state->u64[1] += clk[1]; \
state->u64[2] += clk[0]; \
state->u64[3] += clk[1]; \
clk[1] += FIO_U64_HASH_PRIME0; \
clk[0] += fio_lrot64(clk[0], 27); \
clk[0] += fio_lrot64(clk[0], 49); \
clk[1] += fio_lrot64(clk[1], 27); \
clk[1] += fio_lrot64(clk[1], 49); \
state[0] += clk[0]; \
state[1] += clk[1]; \
state[2] += clk[0]; \
state[3] += clk[1]; \
} \
} \
/** Returns a 128 bit pseudo-random number. */ \
FIO_IFUNC fio_u128 name##128(void) { \
fio_u256 r, t; \
FIO_IFUNC fio_u128 name##___rand(void) { \
fio_u256 r; \
if (reseed_log && reseed_log < 32) { \
static size_t counter; \
if (!((counter++) & ((1ULL << reseed_log) - 1))) \
name##___state_reseed(&name##___state); \
name##___state_reseed(name##___state); \
} \
t = name##___state; \
r.u64[0] = fio_math_mulc64(t.u64[0], FIO_U64_HASH_PRIME0, r.u64 + 1); \
r.u64[2] = fio_math_mulc64(t.u64[2], FIO_U64_HASH_PRIME1, r.u64 + 3); \
/* rotate 256 bit state by 96 bits and add */ \
FIO_MATH_UXXX_SUFFLE(t, 32, 3, 4, 5, 6, 7, 0, 1, 2); \
FIO_MATH_UXXX_OP(r, r, t, 32, +); \
name##___state = r; \
r.u64[0] ^= r.u64[2]; \
r.u64[1] ^= r.u64[3]; \
uint64_t s1[4]; \
{ /* load state to registers and roll, mul, add */ \
const uint64_t s0[] = {name##___state[0], \
name##___state[1], \
name##___state[2], \
name##___state[3]}; \
const uint64_t mulp[] = {0x37701261ED6C16C7ULL, \
0x764DBBB75F3B3E0DULL, \
~(0x37701261ED6C16C7ULL), \
~(0x764DBBB75F3B3E0DULL)}; \
const uint64_t addc[] = {FIO_U64_HASH_PRIME0, \
FIO_U64_HASH_PRIME1, \
FIO_U64_HASH_PRIME2, \
FIO_U64_HASH_PRIME3}; \
for (size_t i = 0; i < 4; ++i) { \
s1[i] = fio_lrot64(s0[i], 33); \
s1[i] += addc[i]; \
s1[i] *= mulp[i]; \
s1[i] += s0[i]; \
} \
} \
for (size_t i = 0; i < 4; ++i) /* store to memory */ \
name##___state[i] = s1[i]; \
{ \
const uint8_t rotc[] = {31, 29, 27, 30}; \
for (size_t i = 0; i < 4; ++i) \
r.u64[i] = fio_lrot64(s1[i], rotc[i]); \
} \
r.u64[0] += r.u64[2]; \
r.u64[1] += r.u64[3]; \
return r.u128[0]; \
} \
/** Returns a 64 bit pseudo-random number. */ \
extern uint64_t name##64(void) { \
fio_u128 r = name##128(); \
fio_u128 r = name##___rand(); \
return r.u64[0]; \
} \
/** Fills the `dest` buffer with pseudo-random noise. */ \
Expand All @@ -3298,12 +3322,12 @@ Defining a Pseudo-Random Number Generator Function (deterministic / not)
return; \
uint8_t *d = (uint8_t *)dest; \
for (unsigned i = 15; i < len; i += 16) { \
fio_u128 r = name##128(); \
fio_u128 r = name##___rand(); \
fio_memcpy16(d, r.u8); \
d += 16; \
} \
if (len & 15) { \
fio_u128 r = name##128(); \
fio_u128 r = name##___rand(); \
fio_memcpy15x(d, r.u8, len); \
} \
}
Expand Down
3 changes: 2 additions & 1 deletion fio-stl/002 random.h
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Original file line number Diff line number Diff line change
Expand Up @@ -330,10 +330,11 @@ SFUNC uint64_t fio_rand64(void) {
/* re-seed state every 4095 requests / 2^12-1 attempts */
fio_rand_reseed();
}
/* load to registers */
const uint64_t s0[] = {fio___rand_state[0],
fio___rand_state[1],
fio___rand_state[2],
fio___rand_state[3]}; /* load to registers */
fio___rand_state[3]};
uint64_t s1[4] = {0};
{
const uint64_t mulp[] = {0x37701261ED6C16C7ULL,
Expand Down
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