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| author | Janne Blomqvist <jb@gcc.gnu.org> | 2019-08-13 11:24:43 +0300 |
|---|---|---|
| committer | Janne Blomqvist <jb@gcc.gnu.org> | 2019-08-13 11:24:43 +0300 |
| commit | 0e99e0933984e0c30fda1d089bfbd6857fc9273f (patch) | |
| tree | 3f4221e36f548096ee6f0e64dab1b2660ceda1c6 /gcc/fortran/check.c | |
| parent | 519acab098317f6eab49b612e49d8fcc6562da8f (diff) | |
| download | gcc-0e99e0933984e0c30fda1d089bfbd6857fc9273f.zip gcc-0e99e0933984e0c30fda1d089bfbd6857fc9273f.tar.gz gcc-0e99e0933984e0c30fda1d089bfbd6857fc9273f.tar.bz2 | |
PR fortran/91414: Improved PRNG
Update the PRNG from xorshift1024* to xoshiro256** by the same
author. For details see
http://prng.di.unimi.it/
and the paper at
https://arxiv.org/abs/1805.01407
Also the seeding is slightly improved, by reading only 8 bytes from
the operating system and using the simple splitmix64 PRNG to fill in
the rest of the PRNG state (as recommended by the xoshiro author),
instead of reading the entire state from the OS.
Regtested on x86_64-pc-linux-gnu, Ok for trunk?
gcc/fortran/ChangeLog:
2019-08-13 Janne Blomqvist <jb@gcc.gnu.org>
PR fortran/91414
* check.c (gfc_check_random_seed): Reduce seed_size.
* intrinsic.texi (RANDOM_NUMBER): Update to match new PRNG.
gcc/testsuite/ChangeLog:
2019-08-13 Janne Blomqvist <jb@gcc.gnu.org>
PR fortran/91414
* gfortran.dg/random_seed_1.f90: Update to match new seed size.
libgfortran/ChangeLog:
2019-08-13 Janne Blomqvist <jb@gcc.gnu.org>
PR fortran/91414
* intrinsics/random.c (prng_state): Update state struct.
(master_state): Update to match new size.
(get_rand_state): Update to match new PRNG.
(rotl): New function.
(xorshift1024star): Replace with prng_next.
(prng_next): New function.
(jump): Update for new PRNG.
(lcg_parkmiller): Replace with splitmix64.
(splitmix64): New function.
(getosrandom): Fix return value, simplify.
(init_rand_state): Use getosrandom only to get 8 bytes, splitmix64
to fill rest of state.
(random_r4): Update to new function and struct names.
(random_r8): Likewise.
(random_r10): Likewise.
(random_r16): Likewise.
(arandom_r4): Liekwise.
(arandom_r8): Likewise.
(arandom_r10): Likwewise.
(arandom_r16): Likewise.
(xor_keys): Reduce size to match new PRNG.
(random_seed_i4): Update to new function and struct names, remove
special handling of variable p used in previous PRNG.
(random_seed_i8): Likewise.
From-SVN: r274361
Diffstat (limited to 'gcc/fortran/check.c')
| -rw-r--r-- | gcc/fortran/check.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c index 370a3c8..2bd8bc3 100644 --- a/gcc/fortran/check.c +++ b/gcc/fortran/check.c @@ -6484,9 +6484,8 @@ gfc_check_random_seed (gfc_expr *size, gfc_expr *put, gfc_expr *get) mpz_t put_size, get_size; /* Keep the number of bytes in sync with master_state in - libgfortran/intrinsics/random.c. +1 due to the integer p which is - part of the state too. */ - seed_size = 128 / gfc_default_integer_kind + 1; + libgfortran/intrinsics/random.c. */ + seed_size = 32 / gfc_default_integer_kind; if (size != NULL) { |