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The seed passed to $random() should not change the implicit seed.

This commit is contained in:
Cary R 2013-09-23 17:42:13 -07:00
parent d564e054e5
commit 68db6c5a65
1 changed files with 7 additions and 6 deletions
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13
vpi/sys_random.c
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2000-2011 Stephen Williams (steve@icarus.com)
* Copyright (c) 2000-2013 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
@ -525,6 +525,7 @@ static PLI_INT32 sys_random_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name)
vpiHandle callh, argv, seed = 0;
s_vpi_value val;
static long i_seed = 0;
long a_seed;
/* Get the argument list and look for a seed. If it is there,
get the value and reseed the random number generator. */
@ -535,18 +536,18 @@ static PLI_INT32 sys_random_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name)
seed = vpi_scan(argv);
vpi_free_object(argv);
vpi_get_value(seed, &val);
i_seed = val.value.integer;
}
a_seed = val.value.integer;
} else a_seed = i_seed;
/* Calculate and return the result. */
val.value.integer = rtl_dist_uniform(&i_seed, INT_MIN, INT_MAX);
val.value.integer = rtl_dist_uniform(&a_seed, INT_MIN, INT_MAX);
vpi_put_value(callh, &val, 0, vpiNoDelay);
/* If it exists send the updated seed back to seed parameter. */
if (seed) {
val.value.integer = i_seed;
val.value.integer = a_seed;
vpi_put_value(seed, &val, 0, vpiNoDelay);
}
} else i_seed = a_seed;
return 0;
}