Faster radix conversion

demo/test.c

@@ -1151,13 +1151,19 @@ static int test_mp_montgomery_reduce(void)
 
 }
 
+#include <time.h>
 static int test_mp_read_radix(void)
 {
    char buf[4096];
-   size_t written;
+   size_t written, maxlen;
+   int bignum, i;
 
-   mp_int a;
-   DOR(mp_init_multi(&a, NULL));
+   char *buffer, *bcpy, *startb;
+
+   clock_t start, stop, t_slow, t_fast;
+
+   mp_int a, b;
+   DOR(mp_init_multi(&a, &b, NULL));
 
    DO(mp_read_radix(&a, "123456", 10));
 
@@ -1183,6 +1189,84 @@ static int test_mp_read_radix(void)
    DO(mp_to_radix(&a, buf, sizeof(buf), &written, 10));
    printf("\r '0' a == %s, length = %zu", buf, written);
 
+   /* Test the fast method with a slightly larger number */
+
+   /* Needs to be big enough to make a sufficiently large timing difference */
+   bignum = 30000;
+   buffer = (char *)malloc((size_t)(bignum + 2));
+   if (buffer == NULL) {
+      goto LBL_ERR;
+   }
+   DO(mp_rand(&a, bignum / MP_DIGIT_BIT));
+   fprintf(stderr,"\nNumber of limbs in &b = %d, bit_count of &b = %d\n", bignum / MP_DIGIT_BIT, mp_count_bits(&a));
+   start = clock();
+   for (i = 2; i < 65; i++) {
+      /* printf("FAST radix = %d\n",i); */
+      DO(mp_to_radix(&a, buffer, (size_t)(bignum + 1), &written, i));
+      mp_zero(&b);
+      DO(mp_read_radix(&b, buffer, i));
+      EXPECT(mp_cmp(&a, &b) == MP_EQ);
+   }
+   stop = clock();
+   t_fast = stop - start;
+
+   printf("Same number, slow radix conversions\n");
+   start = clock();
+   for (i = 2; i < 65; i++) {
+      /* printf("SLOW radix = %d\n",i); */
+      maxlen = (size_t)(bignum + 1);
+      bcpy = buffer;
+      /* s_mp_slower_to_radix is very rudimentary as a stand-alone */
+      startb = bcpy;
+      DO(s_mp_slower_to_radix(&a, &bcpy, &maxlen, &written, i, false));
+      bcpy = startb;
+      mp_zero(&b);
+      DO(s_mp_slower_read_radix(&b, bcpy, 0, strlen(bcpy), i));
+      EXPECT(mp_cmp(&a, &b) == MP_EQ);
+   }
+   stop = clock();
+   t_slow = stop - start;
+
+   /* It is "long int" in GLibC but can be bigger and/or even a floating point elsewhere */
+   fprintf(stderr,"SLOW: %.10f, FAST: %.10f\n", (double)t_slow/(double)CLOCKS_PER_SEC,
+           (double)t_fast/(double)CLOCKS_PER_SEC);
+
+   /* Check if the branching works. */
+   if (MP_HAS(S_MP_FASTER_READ_RADIX) && MP_HAS(S_MP_FASTER_TO_RADIX)) {
+      if (t_fast > t_slow) {
+         fprintf(stderr, "Timing suspicious in test_mp_read_radix. No fast multiplication? Cut-off too low?\n");
+         DO(mp_fwrite(&a, 16, stderr));
+         goto LBL_ERR;
+      }
+   }
+
+   free(buffer);
+
+#if ((MP_DIGIT_BIT <= 16) && (defined MP_CHECK_RADIX_OVF))
+   /* Check a number of size (MP_MAX_DIGIT_COUNT * MP_DIGIT_BIT - 1) at fixed radix "10". */
+   /* Will not work if test is run on platforms with larger int's because
+         #define MP_MAX_DIGIT_COUNT ((INT_MAX - 2) / MP_DIGIT_BIT)
+      So we have to replace the value for INT_MAX with 2^15 - 1 = 32767 to test 16-bit int's. Not
+      very elegant but it works.
+   */
+   bignum = ((32767 - 2) / MP_DIGIT_BIT);
+   bignum = ((bignum - 1) * MP_DIGIT_BIT) + (MP_DIGIT_BIT - 1);
+   /* Manual computation because the automatic methods might not have been included in the build */
+   buffer = (char *)malloc(((bignum + 2)/1000) * 333);
+   if (buffer == NULL) {
+      goto LBL_ERR;
+   }
+   DO(mp_2expt(&a, bignum));
+   DO(mp_decr(&a));
+   printf("Number of limbs in &b = %d, bit_count of &b = %d\n", bignum / MP_DIGIT_BIT, mp_count_bits(&a));
+   DO(mp_to_radix(&a, buffer, ((bignum + 2)/1000) * 333, &written, 10));
+   DO(mp_read_radix(&b, buffer, 10));
+   EXPECT(mp_cmp(&a, &b) == MP_EQ);
+   free(buffer);
+#endif
+
+
+
    while (0) {
       char *s = fgets(buf, sizeof(buf), stdin);
       if (s != buf) break;
@@ -1192,10 +1276,10 @@ static int test_mp_read_radix(void)
       printf("%s, %lu\n", buf, (unsigned long)a.dp[0] & 3uL);
    }
 
-   mp_clear(&a);
+   mp_clear_multi(&a, &b, NULL);
    return EXIT_SUCCESS;
 LBL_ERR:
-   mp_clear(&a);
+   mp_clear_multi(&a, &b, NULL);
    return EXIT_FAILURE;
 }
 
@@ -2479,7 +2563,7 @@ static int unit_tests(int argc, char **argv)
       T1(mp_prime_next_prime, MP_PRIME_NEXT_PRIME),
       T1(mp_prime_rand, MP_PRIME_RAND),
       T1(mp_rand, MP_RAND),
-      T1(mp_read_radix, MP_READ_RADIX),
+      T3(mp_read_radix, ONLY_PUBLIC_API, MP_READ_RADIX, MP_TO_RADIX),
       T1(mp_read_write_ubin, MP_TO_UBIN),
       T1(mp_read_write_sbin, MP_TO_SBIN),
       T1(mp_reduce_2k, MP_REDUCE_2K),

libtommath_VS2008.vcproj

@@ -832,6 +832,18 @@
 			RelativePath="s_mp_exptmod_fast.c"
 			>
 		</File>
+		<File
+			RelativePath="s_mp_faster_read_radix.c"
+			>
+		</File>
+		<File
+			RelativePath="s_mp_faster_to_radix.c"
+			>
+		</File>
+		<File
+			RelativePath="s_mp_floor_ilog2.c"
+			>
+		</File>
 		<File
 			RelativePath="s_mp_fp_log.c"
 			>
@@ -908,6 +920,14 @@
 			RelativePath="s_mp_rand_platform.c"
 			>
 		</File>
+		<File
+			RelativePath="s_mp_slower_read_radix.c"
+			>
+		</File>
+		<File
+			RelativePath="s_mp_slower_to_radix.c"
+			>
+		</File>
 		<File
 			RelativePath="s_mp_sqr.c"
 			>

makefile

@@ -44,12 +44,13 @@ mp_reduce_setup.o mp_root_n.o mp_rshd.o mp_sbin_size.o mp_set.o mp_set_double.o
 mp_set_l.o mp_set_u32.o mp_set_u64.o mp_set_ul.o mp_shrink.o mp_signed_rsh.o mp_sqrmod.o mp_sqrt.o \
 mp_sqrtmod_prime.o mp_sub.o mp_sub_d.o mp_submod.o mp_to_radix.o mp_to_sbin.o mp_to_ubin.o mp_ubin_size.o \
 mp_unpack.o mp_xor.o mp_zero.o s_mp_add.o s_mp_copy_digs.o s_mp_div_3.o s_mp_div_recursive.o \
-s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_fp_log.o s_mp_fp_log_d.o \
-s_mp_get_bit.o s_mp_invmod.o s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o \
-s_mp_mul_balance.o s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o \
-s_mp_mul_toom.o s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o \
-s_mp_radix_size_overestimate.o s_mp_rand_platform.o s_mp_sqr.o s_mp_sqr_comba.o s_mp_sqr_karatsuba.o \
-s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
+s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_faster_read_radix.o \
+s_mp_faster_to_radix.o s_mp_floor_ilog2.o s_mp_fp_log.o s_mp_fp_log_d.o s_mp_get_bit.o s_mp_invmod.o \
+s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o s_mp_mul_balance.o \
+s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o s_mp_mul_toom.o \
+s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o s_mp_radix_size_overestimate.o \
+s_mp_rand_platform.o s_mp_slower_read_radix.o s_mp_slower_to_radix.o s_mp_sqr.o s_mp_sqr_comba.o \
+s_mp_sqr_karatsuba.o s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
 
 #END_INS
 

makefile.mingw

@@ -46,12 +46,13 @@ mp_reduce_setup.o mp_root_n.o mp_rshd.o mp_sbin_size.o mp_set.o mp_set_double.o
 mp_set_l.o mp_set_u32.o mp_set_u64.o mp_set_ul.o mp_shrink.o mp_signed_rsh.o mp_sqrmod.o mp_sqrt.o \
 mp_sqrtmod_prime.o mp_sub.o mp_sub_d.o mp_submod.o mp_to_radix.o mp_to_sbin.o mp_to_ubin.o mp_ubin_size.o \
 mp_unpack.o mp_xor.o mp_zero.o s_mp_add.o s_mp_copy_digs.o s_mp_div_3.o s_mp_div_recursive.o \
-s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_fp_log.o s_mp_fp_log_d.o \
-s_mp_get_bit.o s_mp_invmod.o s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o \
-s_mp_mul_balance.o s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o \
-s_mp_mul_toom.o s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o \
-s_mp_radix_size_overestimate.o s_mp_rand_platform.o s_mp_sqr.o s_mp_sqr_comba.o s_mp_sqr_karatsuba.o \
-s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
+s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_faster_read_radix.o \
+s_mp_faster_to_radix.o s_mp_floor_ilog2.o s_mp_fp_log.o s_mp_fp_log_d.o s_mp_get_bit.o s_mp_invmod.o \
+s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o s_mp_mul_balance.o \
+s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o s_mp_mul_toom.o \
+s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o s_mp_radix_size_overestimate.o \
+s_mp_rand_platform.o s_mp_slower_read_radix.o s_mp_slower_to_radix.o s_mp_sqr.o s_mp_sqr_comba.o \
+s_mp_sqr_karatsuba.o s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
 
 HEADERS_PUB=tommath.h
 HEADERS=tommath_private.h tommath_class.h tommath_superclass.h tommath_cutoffs.h $(HEADERS_PUB)

makefile.msvc

@@ -42,12 +42,13 @@ mp_reduce_setup.obj mp_root_n.obj mp_rshd.obj mp_sbin_size.obj mp_set.obj mp_set
 mp_set_l.obj mp_set_u32.obj mp_set_u64.obj mp_set_ul.obj mp_shrink.obj mp_signed_rsh.obj mp_sqrmod.obj mp_sqrt.obj \
 mp_sqrtmod_prime.obj mp_sub.obj mp_sub_d.obj mp_submod.obj mp_to_radix.obj mp_to_sbin.obj mp_to_ubin.obj mp_ubin_size.obj \
 mp_unpack.obj mp_xor.obj mp_zero.obj s_mp_add.obj s_mp_copy_digs.obj s_mp_div_3.obj s_mp_div_recursive.obj \
-s_mp_div_school.obj s_mp_div_small.obj s_mp_exptmod.obj s_mp_exptmod_fast.obj s_mp_fp_log.obj s_mp_fp_log_d.obj \
-s_mp_get_bit.obj s_mp_invmod.obj s_mp_invmod_odd.obj s_mp_log_2expt.obj s_mp_montgomery_reduce_comba.obj s_mp_mul.obj \
-s_mp_mul_balance.obj s_mp_mul_comba.obj s_mp_mul_high.obj s_mp_mul_high_comba.obj s_mp_mul_karatsuba.obj \
-s_mp_mul_toom.obj s_mp_prime_is_divisible.obj s_mp_prime_tab.obj s_mp_radix_map.obj \
-s_mp_radix_size_overestimate.obj s_mp_rand_platform.obj s_mp_sqr.obj s_mp_sqr_comba.obj s_mp_sqr_karatsuba.obj \
-s_mp_sqr_toom.obj s_mp_sub.obj s_mp_zero_buf.obj s_mp_zero_digs.obj
+s_mp_div_school.obj s_mp_div_small.obj s_mp_exptmod.obj s_mp_exptmod_fast.obj s_mp_faster_read_radix.obj \
+s_mp_faster_to_radix.obj s_mp_floor_ilog2.obj s_mp_fp_log.obj s_mp_fp_log_d.obj s_mp_get_bit.obj s_mp_invmod.obj \
+s_mp_invmod_odd.obj s_mp_log_2expt.obj s_mp_montgomery_reduce_comba.obj s_mp_mul.obj s_mp_mul_balance.obj \
+s_mp_mul_comba.obj s_mp_mul_high.obj s_mp_mul_high_comba.obj s_mp_mul_karatsuba.obj s_mp_mul_toom.obj \
+s_mp_prime_is_divisible.obj s_mp_prime_tab.obj s_mp_radix_map.obj s_mp_radix_size_overestimate.obj \
+s_mp_rand_platform.obj s_mp_slower_read_radix.obj s_mp_slower_to_radix.obj s_mp_sqr.obj s_mp_sqr_comba.obj \
+s_mp_sqr_karatsuba.obj s_mp_sqr_toom.obj s_mp_sub.obj s_mp_zero_buf.obj s_mp_zero_digs.obj
 
 HEADERS_PUB=tommath.h
 HEADERS=tommath_private.h tommath_class.h tommath_superclass.h tommath_cutoffs.h $(HEADERS_PUB)

makefile.shared

@@ -41,12 +41,13 @@ mp_reduce_setup.o mp_root_n.o mp_rshd.o mp_sbin_size.o mp_set.o mp_set_double.o
 mp_set_l.o mp_set_u32.o mp_set_u64.o mp_set_ul.o mp_shrink.o mp_signed_rsh.o mp_sqrmod.o mp_sqrt.o \
 mp_sqrtmod_prime.o mp_sub.o mp_sub_d.o mp_submod.o mp_to_radix.o mp_to_sbin.o mp_to_ubin.o mp_ubin_size.o \
 mp_unpack.o mp_xor.o mp_zero.o s_mp_add.o s_mp_copy_digs.o s_mp_div_3.o s_mp_div_recursive.o \
-s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_fp_log.o s_mp_fp_log_d.o \
-s_mp_get_bit.o s_mp_invmod.o s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o \
-s_mp_mul_balance.o s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o \
-s_mp_mul_toom.o s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o \
-s_mp_radix_size_overestimate.o s_mp_rand_platform.o s_mp_sqr.o s_mp_sqr_comba.o s_mp_sqr_karatsuba.o \
-s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
+s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_faster_read_radix.o \
+s_mp_faster_to_radix.o s_mp_floor_ilog2.o s_mp_fp_log.o s_mp_fp_log_d.o s_mp_get_bit.o s_mp_invmod.o \
+s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o s_mp_mul_balance.o \
+s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o s_mp_mul_toom.o \
+s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o s_mp_radix_size_overestimate.o \
+s_mp_rand_platform.o s_mp_slower_read_radix.o s_mp_slower_to_radix.o s_mp_sqr.o s_mp_sqr_comba.o \
+s_mp_sqr_karatsuba.o s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
 
 #END_INS
 

makefile.unix

@@ -47,12 +47,13 @@ mp_reduce_setup.o mp_root_n.o mp_rshd.o mp_sbin_size.o mp_set.o mp_set_double.o
 mp_set_l.o mp_set_u32.o mp_set_u64.o mp_set_ul.o mp_shrink.o mp_signed_rsh.o mp_sqrmod.o mp_sqrt.o \
 mp_sqrtmod_prime.o mp_sub.o mp_sub_d.o mp_submod.o mp_to_radix.o mp_to_sbin.o mp_to_ubin.o mp_ubin_size.o \
 mp_unpack.o mp_xor.o mp_zero.o s_mp_add.o s_mp_copy_digs.o s_mp_div_3.o s_mp_div_recursive.o \
-s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_fp_log.o s_mp_fp_log_d.o \
-s_mp_get_bit.o s_mp_invmod.o s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o \
-s_mp_mul_balance.o s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o \
-s_mp_mul_toom.o s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o \
-s_mp_radix_size_overestimate.o s_mp_rand_platform.o s_mp_sqr.o s_mp_sqr_comba.o s_mp_sqr_karatsuba.o \
-s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
+s_mp_div_school.o s_mp_div_small.o s_mp_exptmod.o s_mp_exptmod_fast.o s_mp_faster_read_radix.o \
+s_mp_faster_to_radix.o s_mp_floor_ilog2.o s_mp_fp_log.o s_mp_fp_log_d.o s_mp_get_bit.o s_mp_invmod.o \
+s_mp_invmod_odd.o s_mp_log_2expt.o s_mp_montgomery_reduce_comba.o s_mp_mul.o s_mp_mul_balance.o \
+s_mp_mul_comba.o s_mp_mul_high.o s_mp_mul_high_comba.o s_mp_mul_karatsuba.o s_mp_mul_toom.o \
+s_mp_prime_is_divisible.o s_mp_prime_tab.o s_mp_radix_map.o s_mp_radix_size_overestimate.o \
+s_mp_rand_platform.o s_mp_slower_read_radix.o s_mp_slower_to_radix.o s_mp_sqr.o s_mp_sqr_comba.o \
+s_mp_sqr_karatsuba.o s_mp_sqr_toom.o s_mp_sub.o s_mp_zero_buf.o s_mp_zero_digs.o
 
 
 HEADERS_PUB=tommath.h

mp_prime_is_prime.c

@@ -3,16 +3,6 @@
 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
 /* SPDX-License-Identifier: Unlicense */
 
-/* portable integer log of two with small footprint */
-static unsigned int s_floor_ilog2(int value)
-{
-   unsigned int r = 0;
-   while ((value >>= 1) != 0) {
-      r++;
-   }
-   return r;
-}
-
 mp_err mp_prime_is_prime(const mp_int *a, int t, bool *result)
 {
    mp_int  b;
@@ -186,7 +176,7 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, bool *result)
        * Hence the ugly type-fiddling in the following code.
        */
       size_a = mp_count_bits(a);
-      mask = (1u << s_floor_ilog2(size_a)) - 1u;
+      mask = (1u << s_mp_floor_ilog2((unsigned int)size_a)) - 1u;
       /*
          Assuming the General Rieman hypothesis (never thought to write that in a
          comment) the upper bound can be lowered to  2*(log a)^2.

mp_read_radix.c

@@ -3,11 +3,30 @@
 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
 /* SPDX-License-Identifier: Unlicense */
 
+#ifdef MP_USE_MEMOPS
+#  include <string.h>
+
+#  define MP_STRLEN(s) strlen(s)
+#else
+static size_t s_mp_strlen(const char *s)
+{
+   const char *p;
+   p = s;
+   while (*p != '\0') {
+      p++;
+   }
+   return (size_t)(p - s);
+}
+#  define MP_STRLEN(s) s_mp_strlen(s)
+#endif
+
 /* read a string [ASCII] in a given radix */
 mp_err mp_read_radix(mp_int *a, const char *str, int radix)
 {
+
    mp_err   err;
    mp_sign  sign = MP_ZPOS;
+   size_t slen;
 
    /* make sure the radix is ok */
    if ((radix < 2) || (radix > 64)) {
@@ -22,48 +41,24 @@ mp_err mp_read_radix(mp_int *a, const char *str, int radix)
       sign = MP_NEG;
    }
 
-   /* set the integer to the default of zero */
-   mp_zero(a);
+   slen = MP_STRLEN(str);
 
-   /* process each digit of the string */
-   while (*str != '\0') {
-      /* if the radix <= 36 the conversion is case insensitive
-       * this allows numbers like 1AB and 1ab to represent the same  value
-       * [e.g. in hex]
-       */
-      uint8_t y;
-      char ch = (radix <= 36) ? (char)MP_TOUPPER((int)*str) : *str;
-      unsigned pos = (unsigned)(ch - '+');
-      if (MP_RADIX_MAP_REVERSE_SIZE <= pos) {
-         break;
-      }
-      y = s_mp_radix_map_reverse[pos];
+   mp_zero(a);
 
-      /* if the char was found in the map
-       * and is less than the given radix add it
-       * to the number, otherwise exit the loop.
-       */
-      if (y >= radix) {
-         break;
-      }
-      if ((err = mp_mul_d(a, (mp_digit)radix, a)) != MP_OKAY) {
-         return err;
-      }
-      if ((err = mp_add_d(a, y, a)) != MP_OKAY) {
-         return err;
-      }
-      ++str;
-   }
-
-   /* if an illegal character was found, fail. */
-   if ((*str != '\0') && (*str != '\r') && (*str != '\n')) {
-      return MP_VAL;
+   /* Try faster version first */
+   if (MP_HAS(S_MP_FASTER_READ_RADIX)) {
+      if ((err = s_mp_faster_read_radix(a, str, 0, slen, radix)) != MP_OKAY)                             goto LTM_ERR;
+   } else if (MP_HAS(S_MP_SLOWER_READ_RADIX)) {
+      if ((err = s_mp_slower_read_radix(a, str, 0, slen, radix)) != MP_OKAY)                             goto LTM_ERR;
    }
 
    /* set the sign only if a != 0 */
    if (!mp_iszero(a)) {
       a->sign = sign;
    }
-   return MP_OKAY;
+
+LTM_ERR:
+   return err;
 }
+
 #endif