Reorganisation of the source tree

[ghc-hetmet.git] / rts / gmp / mpn / generic / set_str.c

diff --git a/rts/gmp/mpn/generic/set_str.c b/rts/gmp/mpn/generic/set_str.c
new file mode 100644 (file)
index 0000000..e6ccc92
--- /dev/null
+++ b/rts/gmp/mpn/generic/set_str.c
@@ -0,0 +1,159 @@
+/* mpn_set_str (mp_ptr res_ptr, const char *str, size_t str_len, int base)
+   -- Convert a STR_LEN long base BASE byte string pointed to by STR to a
+   limb vector pointed to by RES_PTR.  Return the number of limbs in
+   RES_PTR.
+
+Copyright (C) 1991, 1992, 1993, 1994, 1996, 2000 Free Software Foundation,
+Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MP Library 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+mp_size_t
+#if __STDC__
+mpn_set_str (mp_ptr xp, const unsigned char *str, size_t str_len, int base)
+#else
+mpn_set_str (xp, str, str_len, base)
+     mp_ptr xp;
+     const unsigned char *str;
+     size_t str_len;
+     int base;
+#endif
+{
+  mp_size_t size;
+  mp_limb_t big_base;
+  int indigits_per_limb;
+  mp_limb_t res_digit;
+
+  big_base = __mp_bases[base].big_base;
+  indigits_per_limb = __mp_bases[base].chars_per_limb;
+
+/*   size = str_len / indigits_per_limb + 1;  */
+
+  size = 0;
+
+  if ((base & (base - 1)) == 0)
+    {
+      /* The base is a power of 2.  Read the input string from
+        least to most significant character/digit.  */
+
+      const unsigned char *s;
+      int next_bitpos;
+      int bits_per_indigit = big_base;
+
+      res_digit = 0;
+      next_bitpos = 0;
+
+      for (s = str + str_len - 1; s >= str; s--)
+       {
+         int inp_digit = *s;
+
+         res_digit |= (mp_limb_t) inp_digit << next_bitpos;
+         next_bitpos += bits_per_indigit;
+         if (next_bitpos >= BITS_PER_MP_LIMB)
+           {
+             xp[size++] = res_digit;
+             next_bitpos -= BITS_PER_MP_LIMB;
+             res_digit = inp_digit >> (bits_per_indigit - next_bitpos);
+           }
+       }
+
+      if (res_digit != 0)
+       xp[size++] = res_digit;
+    }
+  else
+    {
+      /* General case.  The base is not a power of 2.  */
+
+      size_t i;
+      int j;
+      mp_limb_t cy_limb;
+
+      for (i = indigits_per_limb; i < str_len; i += indigits_per_limb)
+       {
+         res_digit = *str++;
+         if (base == 10)
+           { /* This is a common case.
+                Help the compiler to avoid multiplication.  */
+             for (j = 1; j < indigits_per_limb; j++)
+               res_digit = res_digit * 10 + *str++;
+           }
+         else
+           {
+             for (j = 1; j < indigits_per_limb; j++)
+               res_digit = res_digit * base + *str++;
+           }
+
+         if (size == 0)
+           {
+             if (res_digit != 0)
+               {
+                 xp[0] = res_digit;
+                 size = 1;
+               }
+           }
+         else
+           {
+             cy_limb = mpn_mul_1 (xp, xp, size, big_base);
+             cy_limb += mpn_add_1 (xp, xp, size, res_digit);
+             if (cy_limb != 0)
+               xp[size++] = cy_limb;
+           }
+       }
+
+      big_base = base;
+      res_digit = *str++;
+      if (base == 10)
+       { /* This is a common case.
+            Help the compiler to avoid multiplication.  */
+         for (j = 1; j < str_len - (i - indigits_per_limb); j++)
+           {
+             res_digit = res_digit * 10 + *str++;
+             big_base *= 10;
+           }
+       }
+      else
+       {
+         for (j = 1; j < str_len - (i - indigits_per_limb); j++)
+           {
+             res_digit = res_digit * base + *str++;
+             big_base *= base;
+           }
+       }
+
+      if (size == 0)
+       {
+         if (res_digit != 0)
+           {
+             xp[0] = res_digit;
+             size = 1;
+           }
+       }
+      else
+       {
+         cy_limb = mpn_mul_1 (xp, xp, size, big_base);
+         cy_limb += mpn_add_1 (xp, xp, size, res_digit);
+         if (cy_limb != 0)
+           xp[size++] = cy_limb;
+       }
+    }
+
+  return size;
+}