First glimmerings of binary polynomial arithmetic.

[u/mdw/catacomb] / gfx-sqr-mktab.c

diff --git a/gfx-sqr-mktab.c b/gfx-sqr-mktab.c
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+/* -*-c-*-
+ *
+ * $Id: gfx-sqr-mktab.c,v 1.1 2000/10/08 15:49:37 mdw Exp $
+ *
+ * Build table for squaring of binary polynomials
+ *
+ * (c) 2000 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.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: gfx-sqr-mktab.c,v $
+ * Revision 1.1  2000/10/08 15:49:37  mdw
+ * First glimmerings of binary polynomial arithmetic.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <mLib/bits.h>
+
+/*----- Main code ---------------------------------------------------------*/
+
+static void mktab(uint16 *t)
+{
+  unsigned i, j, x;
+
+  for (i = 0; i < 256; i++) {
+    x = 0;
+    for (j = 0; j < 8; j++) {
+      if (i & (1 << j))
+       x |= 1 << (2 * j);
+    }
+    t[i] = x;
+  }
+}
+
+int main(void)
+{
+  uint16 t[256];
+  unsigned i;
+
+  mktab(t);
+fputs("\
+/* -*-c-*-\n\
+ *\n\
+ * Bit spacing table for binary polynomial squaring\n\
+ */\n\
+\n\
+#ifndef GFX_SQR_TAB_H\n\
+#define GFX_SQR_TAB_H\n\
+\n\
+#define GFX_SQRTAB {                                                   \\\n\
+  ", stdout);
+
+  for (i = 0; i < 256; i++) {
+    printf("0x%04x", t[i]);
+    if (i == 255)
+      puts("   \\\n}\n");
+    else if (i % 8 == 7)
+      fputs(", \\\n  ", stdout);
+    else
+      fputs(", ", stdout);
+  }
+
+  fputs("#endif\n", stdout);
+
+  if (fclose(stdout)) {
+    fprintf(stderr, "error writing data\n");
+    exit(EXIT_FAILURE);
+  }
+
+  return (0);
+}
+
+/*----- That's all, folks -------------------------------------------------*/