* arith.c (highest_significant_bit): New static function.

(comp_clamp): Bugfix: avoid shifting left into sign bit. Function
renamed to comp_trunc.
(logtrunc, ash): New functions.

* eval.c (eval_init): Registered logtrunc and ash intrinsics.

* lib.h (logtrunc, ash): Declared.

* mpi-patches/add-bitops (s_highest_bit_mp): Forward declaration for
added.
(mp_clamp_comp): Bugfix in handling remainder bits. Function
renamed to mp_trunc_comp.
(mp_trunc, mp_shift): New functions.

1 files changed, 110 insertions, 7 deletions

diff --git a/mpi-patches/add-bitops b/mpi-patches/add-bitops
index 7e8dc696..7eae01cb 100644
--- a/mpi-patches/add-bitops
+++ b/mpi-patches/add-bitops
@@ -1,7 +1,7 @@
 Index: mpi-1.8.6/mpi.c
 ===================================================================
 --- mpi-1.8.6.orig/mpi.c	2012-09-16 10:50:08.270639006 -0700
-+++ mpi-1.8.6/mpi.c	2012-09-16 23:09:57.601600506 -0700
++++ mpi-1.8.6/mpi.c	2012-09-17 07:33:38.563334756 -0700
 @@ -16,6 +16,9 @@
  #include <ctype.h>
  #include <math.h>
@@ -12,7 +12,15 @@ Index: mpi-1.8.6/mpi.c
  typedef unsigned char mem_t;
  extern mem_t *chk_malloc(size_t size);
  extern mem_t *chk_calloc(size_t n, size_t size);
-@@ -2330,6 +2333,321 @@
+@@ -159,6 +162,7 @@
+ mp_err   s_mp_grow(mp_int *mp, mp_size min);   /* increase allocated size */
+ mp_err   s_mp_pad(mp_int *mp, mp_size min);    /* left pad with zeroes    */
+ 
++static int s_highest_bit(mp_digit n);
+ int      s_highest_bit_mp(mp_int *a);
+ mp_err   s_mp_set_bit(mp_int *a, int bit);
+ 
+@@ -2330,6 +2334,414 @@
  
  /* }}} */
  
@@ -287,7 +295,7 @@ Index: mpi-1.8.6/mpi.c
 +  return MP_OKAY;
 +}
 +
-+mp_err mp_clamp_comp(mp_int *a, mp_int *b, mp_digit bits)
++mp_err mp_trunc_comp(mp_int *a, mp_int *b, mp_digit bits)
 +{
 +  mp_err res;
 +  mp_size ix, dig = bits / DIGIT_BIT, rembits = bits % DIGIT_BIT;
@@ -319,7 +327,51 @@ Index: mpi-1.8.6/mpi.c
 +
 +  if (rembits) {
 +    mp_digit mask = (MP_DIGIT_MAX >> (DIGIT_BIT - rembits));
-+    pb[ix] = (pa[ix] & mask) ^ mask;
++    pb[ix] = (((ix < adig) ? pa[ix] : padding) & mask) ^ mask;
++  }
++
++  USED(b) = dig + extra;
++
++  if (ISNEG(a))
++    mp_clear(&tmp);
++
++  s_mp_clamp(b);
++  return MP_OKAY;
++}
++
++mp_err mp_trunc(mp_int *a, mp_int *b, mp_digit bits)
++{
++  mp_err res;
++  mp_size ix, dig = bits / DIGIT_BIT, rembits = bits % DIGIT_BIT;
++  mp_size adig = USED(a);
++  mp_digit padding = ISNEG(a) ? MP_DIGIT_MAX : 0;
++  int extra = (rembits != 0);
++  mp_digit *pa, *pb;
++  mp_int tmp;
++
++  ARGCHK(a != NULL && b != NULL, MP_BADARG);
++
++  if (a != b)
++    res = mp_init_size(b, dig + extra);
++  else
++    res = s_mp_pad(b, dig + extra);
++
++  if (res != MP_OKAY)
++    return res;
++
++  if (ISNEG(a)) {
++    mp_init_size(&tmp, dig + extra);
++    if ((res = mp_2comp(a, &tmp, dig + extra)) != MP_OKAY)
++	return res;
++    a = &tmp;
++  }
++
++  for (pa = DIGITS(a), pb = DIGITS(b), ix = 0; ix < dig; ix++)
++    pb[ix] = (ix < adig) ? pa[ix] : padding;
++
++  if (rembits) {
++    mp_digit mask = (MP_DIGIT_MAX >> (DIGIT_BIT - rembits));
++    pb[ix] = ((ix < adig) ? pa[ix] : padding) & mask;
 +  }
 +
 +  USED(b) = dig + extra;
@@ -331,13 +383,62 @@ Index: mpi-1.8.6/mpi.c
 +  return MP_OKAY;
 +}
 +
++mp_err mp_shift(mp_int *a, mp_int *b, int bits)
++{
++  mp_int tmp;
++  mp_err res;
++  int a_neg = ISNEG(a);
++
++  if (bits == 0)
++    return mp_copy(a, b);
++
++  if (a_neg) {
++    mp_size ua = USED(a);
++    mp_init_size(&tmp, ua);
++    if ((res = mp_2comp(a, &tmp, ua)) != MP_OKAY)
++	return res;
++    SIGN(&tmp) = MP_ZPOS;
++    a = &tmp;
++  }
++
++  if (bits > 0)
++    res = mp_mul_2d(a, bits, b);
++  else
++    res = mp_div_2d(a, -bits, b, NULL);
++
++  if (res != MP_OKAY)
++    return res;
++
++  if (a_neg) {
++    int hb, msd;
++    mp_digit *db;
++
++    mp_clear(&tmp);
++
++    msd = USED(b)-1;
++    db = DIGITS(b);
++    hb = s_highest_bit(db[msd]);
++
++    if (hb < DIGIT_BIT)
++	db[msd] |= MP_DIGIT_MAX << hb;
++
++    if ((res = mp_2comp(b, b, USED(b))) != MP_OKAY)
++	return res;
++
++    SIGN(b) = MP_NEG;
++    s_mp_clamp(b);
++  }
++
++  return MP_OKAY;
++}
++
  mp_err mp_to_double(mp_int *mp, double *d)
  {
    int ix;
 Index: mpi-1.8.6/mpi.h
 ===================================================================
 --- mpi-1.8.6.orig/mpi.h	2012-09-16 10:50:08.046513006 -0700
-+++ mpi-1.8.6/mpi.h	2012-09-16 21:45:17.713770006 -0700
++++ mpi-1.8.6/mpi.h	2012-09-17 07:32:54.738697256 -0700
 @@ -54,6 +54,7 @@
  
  /* Macros for accessing the mp_int internals           */
@@ -346,7 +447,7 @@ Index: mpi-1.8.6/mpi.h
  #define  USED(MP)     ((MP)->used)
  #define  ALLOC(MP)    ((MP)->alloc)
  #define  DIGITS(MP)   ((MP)->dp)
-@@ -187,6 +188,15 @@
+@@ -187,6 +188,17 @@
  #endif /* end MP_NUMTH */
  
  /*------------------------------------------------------------------------*/
@@ -356,7 +457,9 @@ Index: mpi-1.8.6/mpi.h
 +mp_err mp_or(mp_int *a, mp_int *b, mp_int *c);
 +mp_err mp_xor(mp_int *a, mp_int *b, mp_int *c);
 +mp_err mp_comp(mp_int *a, mp_int *b);
-+mp_err mp_clamp_comp(mp_int *a, mp_int *b, mp_digit bits);
++mp_err mp_trunc_comp(mp_int *a, mp_int *b, mp_digit bits);
++mp_err mp_trunc(mp_int *a, mp_int *b, mp_digit bits);
++mp_err mp_shift(mp_int *a, mp_int *b, int bits); /* + left, - right */
 +
 +/*------------------------------------------------------------------------*/
  /* Conversions                                                            */