From b8946d4cb3e63b702d356cfa37b5130ffbd6972c Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Sat, 8 Jul 2000 22:41:07 +0000
Subject: [PATCH]  Add the dist_uniform function.

---
 vpi/sys_random.c | 183 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 181 insertions(+), 2 deletions(-)

diff --git a/vpi/sys_random.c b/vpi/sys_random.c
index 1889b7592..745c87450 100644
--- a/vpi/sys_random.c
+++ b/vpi/sys_random.c
@@ -17,12 +17,161 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: sys_random.c,v 1.1 2000/05/04 03:37:59 steve Exp $"
+#ident "$Id: sys_random.c,v 1.2 2000/07/08 22:41:07 steve Exp $"
 #endif
 
 # include  <vpi_user.h>
 # include  <assert.h>
 # include  <stdlib.h>
+# include  <math.h>
+# include  <limits.h>
+
+#if 0
+double uniform(long*seed, long start, long end)
+{
+      union u_s {
+	    float s;
+	    unsigned stemp;
+      } u;
+
+      double d = 0.00000011920928955078125;
+      double a, b, c;
+
+      if ((*seed) == 0)
+	    *seed = 259341593;
+
+      if (start >= end) {
+	    a = 0.0;
+	    b = 2147483647.0;
+
+      } else {
+	    a = (double) start;
+	    b = (double) end;
+      }
+
+      *seed = 69069 * (*seed) + 1;
+      u.stemp = *seed;
+
+      u.stemp = (u.stemp >> 9) | 0x3f800000;
+
+      c = (double) u.s;
+      c = c + (c*d);
+      c = ((b - a) * (c - 1.0)) + a;
+      return c;
+}
+#endif
+
+#if 0
+static long rtl_dist_uniform(long*seed, long start, long end)
+{
+      double r;
+      long i;
+
+      if (start >= end)
+	    return start;
+
+      if (end != LONG_MAX) {
+	    end += 1;
+	    r = uniform(seed, start, end);
+	    if (r >= 0)
+		  i = (long) r;
+	    else
+		  i = (long) (r-1);
+
+	    if (i < start) i = start;
+	    if (i >= end) i = end - 1;
+
+      } else if (start != LONG_MIN) {
+	    start -= 1;
+	    r = uniform(seed, start, end);
+	    if (r >= 0)
+		  i = (long) r;
+	    else
+		  i = (long) (r-1);
+
+	    if (i <= start) i = start;
+	    if (i >  end) i = end;
+
+      } else {
+	    r = (uniform(seed, start, end) + 2147483648.0) / 4294967295.0;
+	    r = r * 4294967296.0 - 2147483648.0;
+	    if (r >= 0)
+		  i = (long) r;
+	    else
+		  i = (long) (r-1);
+      }
+
+      return i;
+}
+#else
+static long rtl_dist_uniform(long*seed, long start, long end)
+{
+      if (start >= end)
+	    return start;
+
+      if ((start > LONG_MIN) || (end < LONG_MAX)) {
+	    long range = end - start;
+	    return start + random()%range;
+      } else {
+	    return random();
+      }
+}
+#endif
+
+
+static int sys_dist_uniform_calltf(char*name)
+{
+      s_vpi_value val;
+      vpiHandle call_handle;
+      vpiHandle argv;
+      vpiHandle seed = 0, start, end;
+
+      long i_seed, i_start, i_end;
+
+      call_handle = vpi_handle(vpiSysTfCall, 0);
+      assert(call_handle);
+
+      argv = vpi_iterate(vpiArgument, call_handle);
+      if (argv == 0) {
+	    vpi_printf("ERROR: %s requires parameters "
+		       "(seed, start, end)\n", name);
+	    return 0;
+      }
+
+      seed = vpi_scan(argv);
+      assert(seed);
+      start = vpi_scan(argv);
+      assert(start);
+      end = vpi_scan(argv);
+      assert(end);
+
+      vpi_free_object(argv);
+
+      val.format = vpiIntVal;
+      vpi_get_value(seed, &val);
+      i_seed = val.value.integer;
+
+      vpi_get_value(start, &val);
+      i_start = val.value.integer;
+
+      vpi_get_value(end, &val);
+      i_end = val.value.integer;
+
+      val.format = vpiIntVal;
+      val.value.integer = rtl_dist_uniform(&i_seed, i_start, i_end);
+      vpi_put_value(call_handle, &val, 0, vpiNoDelay);
+
+      val.format = vpiIntVal;
+      val.value.integer = i_seed;
+      vpi_put_value(seed, &val, 0, vpiNoDelay);
+
+      return 0;
+}
+
+static int sys_dist_uniform_sizetf(char*x)
+{
+      return 32;
+}
 
 /*
  * Implement the $random system function. For now, ignore any
@@ -30,17 +179,36 @@
  */
 static int sys_random_calltf(char*name)
 {
+      static long i_seed = 0;
       s_vpi_value val;
       vpiHandle call_handle;
+      vpiHandle argv;
+      vpiHandle seed = 0;
 
       call_handle = vpi_handle(vpiSysTfCall, 0);
       assert(call_handle);
 
+      argv = vpi_iterate(vpiArgument, call_handle);
+      if (argv) {
+	    seed = vpi_scan(argv);
+	    vpi_free_object(argv);
+
+	    val.format = vpiIntVal;
+	    vpi_get_value(seed, &val);
+	    i_seed = val.value.integer;
+      }
+
       val.format = vpiIntVal;
-      val.value.integer = random();
+      val.value.integer = rtl_dist_uniform(&i_seed, LONG_MIN, LONG_MAX);
 
       vpi_put_value(call_handle, &val, 0, vpiNoDelay);
 
+      if (seed) {
+	    val.format = vpiIntVal;
+	    val.value.integer = i_seed;
+	    vpi_put_value(seed, &val, 0, vpiNoDelay);
+      }
+
       return 0;
 }
 
@@ -60,10 +228,21 @@ void sys_random_register()
       tf_data.sizetf = sys_random_sizetf;
       tf_data.user_data = "$random";
       vpi_register_systf(&tf_data);
+
+      tf_data.type   = vpiSysFunc;
+      tf_data.tfname = "$dist_uniform";
+      tf_data.calltf = sys_dist_uniform_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf = sys_dist_uniform_sizetf;
+      tf_data.user_data = "$dist_uniform";
+      vpi_register_systf(&tf_data);
 }
 
 /*
  * $Log: sys_random.c,v $
+ * Revision 1.2  2000/07/08 22:41:07  steve
+ *  Add the dist_uniform function.
+ *
  * Revision 1.1  2000/05/04 03:37:59  steve
  *  Add infrastructure for system functions, move
  *  $time to that structure and add $random.