primeiter: New functions for iterating over small primes.

[u/mdw/catacomb] / genwheel.c

diff --git a/genwheel.c b/genwheel.c
new file mode 100644 (file)
index 0000000..94d0572
--- /dev/null
+++ b/genwheel.c
@@ -0,0 +1,194 @@
+/* -*-c-*-
+ *
+ * Generate a prime-iteration wheel
+ *
+ * (c) 2007 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <mLib/darray.h>
+#include <mLib/dstr.h>
+#include <mLib/mdwopt.h>
+#include <mLib/quis.h>
+#include <mLib/report.h>
+
+/*----- Data structures ---------------------------------------------------*/
+
+DA_DECL(uintv, unsigned int);
+
+/*----- Main code ---------------------------------------------------------*/
+
+static unsigned long gcd(unsigned long a, unsigned long b)
+{
+  int t;
+  if (!a) return (b);
+  while (b) { t = a%b; a = b; b = t; }
+  return (a);
+}
+
+int main(int argc, char *argv[])
+{
+  int np = 5;
+  const char *type = "unsigned char";
+  const char *source = "wheel.c";
+  const char *header = "wheel.h";
+  const char *name = "wheel";
+  const char *sym = 0;
+  unsigned long i, n;
+  unsigned long mod;
+  int o;
+  uintv v = DA_INIT;
+
+  ego(argv[0]);
+  for (;;) {
+    o = getopt(argc, argv, "n:c:h:s:t:i:");
+    if (o < 0)
+      break;
+    switch (o) {
+      case 'n':
+       np = atoi(optarg);
+       break;
+      case 's':
+       sym = optarg;
+       break;
+      case 'c':
+       source = optarg;
+       break;
+      case 'h':
+       header = optarg;
+       break;
+      case 't':
+       type = optarg;
+       break;
+      case 'i':
+       name = optarg;
+       break;
+      default:
+       pquis(stderr, "Usage: $ [-n nprimes] [-s source] [-h header]\n");
+       exit(EXIT_FAILURE);
+    }
+  }
+
+  for (mod = 1, i = 2, n = 0;
+       n < np;
+       i++) {
+    if (gcd(i, mod) == 1) {
+      mod *= i;
+      n++;
+    }
+  }
+
+  n = 1;
+  for (i = 2; i < mod; i++) {
+    if (gcd(mod, i) == 1) {
+      DA_PUSH(&v, i - n);
+      n = i;
+    }
+  }
+  DA_PUSH(&v, mod + 1 - n);
+
+  {
+    FILE *fp = fopen(header, "w");
+    dstr d = DSTR_INIT;
+    const char *q;
+    if (!fp)
+      die(EXIT_FAILURE, "couldn't write `%s': %s", header, strerror(errno));
+    if (!sym) {
+      for (q = header; *q; q++) {
+       int ch = (unsigned char)*q;
+       if (isalnum(ch))
+         ch = toupper(ch);
+       else
+         ch = '_';
+       DPUTC(&d, ch);
+      }
+      DPUTZ(&d);
+      sym = d.buf;
+    }
+    fprintf(fp, "\
+/* -*-c-*-\n\
+ *\n\
+ * Wheel for small prime iteration [generated]\n\
+ */\n\
+\n\
+#ifndef %s\n\
+#define %s\n\
+\n\
+#define WHEELN %luu\n\
+#define WHEELMOD %luu\n\
+\n\
+extern const %s %s[];\n\
+\n\
+#endif\n\
+",
+           sym, sym,
+           (unsigned long)DA_LEN(&v),
+           mod,
+           type, name);
+    dstr_destroy(&d);
+    if (fclose(fp) == EOF) {
+      remove(header);
+      die(EXIT_FAILURE, "error writing `%s': %s", header, strerror(errno));
+    }
+  }
+
+  {
+    FILE *fp = fopen(source, "w");
+    int i;
+    if (!fp)
+      die(EXIT_FAILURE, "couldn't write `%s': %s", source, strerror(errno));
+    fprintf(fp, "\
+/* -*-c-*-\n\
+ *\n\
+ * Wheel for small prime iteration [generated]\n\
+ */\n\
+\n\
+#include \"%s\"\n\
+\n\
+const %s %s[] = {",
+           header, type, name);
+    for (i = 0; i < DA_LEN(&v); i++) {
+      if (i % 8 == 0)
+       fputs("\n  ", fp);
+      fprintf(fp, "%5u, ", DA(&v)[i]);
+    }
+    fputs("\n\
+};\n\
+", fp);
+    if (fclose(fp) == EOF) {
+      remove(source);
+      die(EXIT_FAILURE, "error writing `%s': %s", source, strerror(errno));
+    }
+  }
+
+  return (0);
+}
+
+/*----- That's all, folks -------------------------------------------------*/