19 static PetscErrorCode PetscRandomSeed_Random123(PetscRandom r)  in PetscRandomSeed_Random123()  argument
22   PetscRandom123     *r123 = (PetscRandom123 *)r->data;  in PetscRandomSeed_Random123()
25   ukey.v[0] = (R123_ULONG_LONG)r->seed;  in PetscRandomSeed_Random123()
31   r123->key          = threefry4x64keyinit(ukey);  in PetscRandomSeed_Random123()
32   r123->counter.v[0] = 0;  in PetscRandomSeed_Random123()
33   r123->counter.v[1] = 1;  in PetscRandomSeed_Random123()
34   r123->counter.v[2] = 2;  in PetscRandomSeed_Random123()
35   r123->counter.v[3] = 3;  in PetscRandomSeed_Random123()
36   r123->result       = threefry4x64(r123->counter, r123->key);  in PetscRandomSeed_Random123()
37   r123->count        = 0;  in PetscRandomSeed_Random123()
45   PetscInt  mod   = (r123->count++) % 4;  in PetscRandom123Step()
48   ret = r123->result.v[mod] * scale + shift;  in PetscRandom123Step()
51     r123->counter.v[0] += 4;  in PetscRandom123Step()
52     r123->counter.v[1] += 4;  in PetscRandom123Step()
53     r123->counter.v[2] += 4;  in PetscRandom123Step()
54     r123->counter.v[3] += 4;  in PetscRandom123Step()
55     r123->result = threefry4x64(r123->counter, r123->key);  in PetscRandom123Step()
61 static PetscErrorCode PetscRandomGetValue_Random123(PetscRandom r, PetscScalar *val)  in PetscRandomGetValue_Random123()  argument
63   PetscRandom123 *r123 = (PetscRandom123 *)r->data;  in PetscRandomGetValue_Random123()
72     if (r->iset) {  in PetscRandomGetValue_Random123()
73       re = re * PetscRealPart(r->width) + PetscRealPart(r->low);  in PetscRandomGetValue_Random123()
74       im = im * PetscImaginaryPart(r->width) + PetscImaginaryPart(r->low);  in PetscRandomGetValue_Random123()
81   if (r->iset) rscal = rscal * r->width + r->low;  in PetscRandomGetValue_Random123()
87 static PetscErrorCode PetscRandomGetValueReal_Random123(PetscRandom r, PetscReal *val)  in PetscRandomGetValueReal_Random123()  argument
89   PetscRandom123 *r123 = (PetscRandom123 *)r->data;  in PetscRandomGetValueReal_Random123()
94   if (r->iset) rreal = rreal * PetscRealPart(r->width) + PetscRealPart(r->low);  in PetscRandomGetValueReal_Random123()
99 static PetscErrorCode PetscRandomGetValuesReal_Random123(PetscRandom r, PetscInt n, PetscReal vals[…  in PetscRandomGetValuesReal_Random123()  argument
101   PetscRandom123 *r123 = (PetscRandom123 *)r->data;  in PetscRandomGetValuesReal_Random123()
109   peel_start = (4 - (r123->count % 4)) % 4;  in PetscRandomGetValuesReal_Random123()
111   for (PetscInt i = 0; i < peel_start; i++) PetscCall(PetscRandomGetValueReal(r, &vals[i]));  in PetscRandomGetValuesReal_Random123()
112   PetscAssert((r123->count % 4) == 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Bad modular arithmetic");  in PetscRandomGetValuesReal_Random123()
113   n -= peel_start;  in PetscRandomGetValuesReal_Random123()
116   lim = n - rem;  in PetscRandomGetValuesReal_Random123()
117   if (r->iset) {  in PetscRandomGetValuesReal_Random123()
118     scale *= PetscRealPart(r->width);  in PetscRandomGetValuesReal_Random123()
119     shift *= PetscRealPart(r->width);  in PetscRandomGetValuesReal_Random123()
120     shift += PetscRealPart(r->low);  in PetscRandomGetValuesReal_Random123()
132     r123_copy.result = threefry4x64(r123->counter, r123->key);  in PetscRandomGetValuesReal_Random123()
136   for (PetscInt i = 0; i < rem; i++) PetscCall(PetscRandomGetValueReal(r, &vals[i]));  in PetscRandomGetValuesReal_Random123()
140 static PetscErrorCode PetscRandomGetValues_Random123(PetscRandom r, PetscInt n, PetscScalar vals[])  in PetscRandomGetValues_Random123()  argument
144   for (PetscInt i = 0; i < n; i++) PetscCall(PetscRandomGetValue_Random123(r, n, &vals[i]));  in PetscRandomGetValues_Random123()
146   PetscCall(PetscRandomGetValuesReal_Random123(r, n, vals));  in PetscRandomGetValues_Random123()
151 static PetscErrorCode PetscRandomDestroy_Random123(PetscRandom r)  in PetscRandomDestroy_Random123()  argument
154   PetscCall(PetscFree(r->data));  in PetscRandomDestroy_Random123()
159   // clang-format off
166   // clang-format on
170 …PETSCRANDOM123 - access to Random123 counter based pseudorandom number generators (currently three…
173 . -random_type <rand,rand48,sprng,random123> - select the random number generator at runtim
178 …PETSc must be ./configure with the option --download-random123 to use this random number generator.
183 PETSC_EXTERN PetscErrorCode PetscRandomCreate_Random123(PetscRandom r)  in PetscRandomCreate_Random123()  argument
189   r->data   = r123;  in PetscRandomCreate_Random123()
190   r->ops[0] = PetscRandomOps_Values;  in PetscRandomCreate_Random123()
191   PetscCall(PetscObjectChangeTypeName((PetscObject)r, PETSCRANDOM123));  in PetscRandomCreate_Random123()
192   PetscCall(PetscRandomSeed(r));  in PetscRandomCreate_Random123()