Add set operations for bool-vector.

http://lists.gnu.org/archive/html/emacs-devel/2013-09/msg00404.html

* data.c (Qbool_vector_p): New symbol.
(bool_vector_spare_mask,popcount_size_t_generic)
(popcount_size_t_msc,popcount_size_t_gcc)
(popcount_size_t)
(bool_vector_binop_driver)
(count_trailing_zero_bits,size_t_to_host_endian)
(Fbool_vector_exclusive_or)
(Fbool_vector_union)
(Fbool_vector_intersection,Fbool_vector_set_difference)
(Fbool_vector_subsetp,Fbool_vector_not)
(Fbool_vector_count_matches)
(Fbool_vector_count_matches_at): New functions.
(syms_of_data): Intern new symbol, functions.
* alloc.c (bool_vector_payload_bytes): New function.
(Fmake_bool_vector): Instead of calling Fmake_vector,
which performs redundant initialization and argument checking,
just call allocate_vector ourselves.  Make sure we clear any
terminating padding to zero.
(vector_nbytes,sweep_vectors): Use bool_vector_payload_bytes
instead of open-coding the size calculation.
(vroundup_ct): New macro.
(vroundup): Assume argument >= 0; invoke vroundup_ct.
* casetab.c (shuffle,set_identity): Change lint_assume to assume.
* composite.c (composition_gstring_put_cache): Change
lint_assume to assume.
* conf_post.h (assume): New macro.
(lint_assume): Remove.
* dispnew.c (update_frame_1): Change lint_assume to assume.
* ftfont.c (ftfont_shape_by_flt): Change lint_assume
to assume.
* image.c (gif_load): Change lint_assume to assume.
* lisp.h (eassert_and_assume): New macro.
(Qbool_vector_p): Declare.
(CHECK_BOOL_VECTOR,ROUNDUP,BITS_PER_SIZE_T): New macros.
(swap16,swap32,swap64): New inline functions.
* macfont.c (macfont_shape): Change lint_assume to assume.
* ralloc.c: Rename ROUNDUP to PAGE_ROUNDUP throughout.
* xsettings.c (parse_settings): Use new swap16 and
swap32 from lisp.h instead of file-specific macros.

1 files changed, 462 insertions, 0 deletions

diff --git a/src/data.c b/src/data.c
index 51b0266eca1..5a05e0652ad 100644
--- a/src/data.c
+++ b/src/data.c
@@ -54,6 +54,7 @@ Lisp_Object Qintegerp, Qwholenump, Qsymbolp, Qlistp, Qconsp;
 static Lisp_Object Qnatnump;
 Lisp_Object Qstringp, Qarrayp, Qsequencep, Qbufferp;
 Lisp_Object Qchar_or_string_p, Qmarkerp, Qinteger_or_marker_p, Qvectorp;
+Lisp_Object Qbool_vector_p;
 Lisp_Object Qbuffer_or_string_p;
 static Lisp_Object Qkeywordp, Qboundp;
 Lisp_Object Qfboundp;
@@ -2956,6 +2957,457 @@ lowercase l) for small endian machines.  */)
   return make_number (order);
 }
 
+/* Because we round up the bool vector allocate size to word_size
+   units, we can safely read past the "end" of the vector in the
+   operations below.  These extra bits are always zero.  Also, we
+   always allocate bool vectors with at least one size_t of storage so
+   that we don't have to special-case empty bit vectors.  */
+
+static inline
+size_t
+bool_vector_spare_mask (ptrdiff_t nr_bits)
+{
+  eassert_and_assume (nr_bits > 0);
+  return (((size_t) 1) << (nr_bits % BITS_PER_SIZE_T)) - 1;
+}
+
+#if __MSC_VER >= 1500 && (defined _M_IX86 || defined _M_X64)
+# define USE_MSC_POPCOUNT
+#elif __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+# define USE_GCC_POPCOUNT
+#else
+# define NEED_GENERIC_POPCOUNT
+#endif
+
+#ifdef USE_MSC_POPCOUNT
+#define NEED_GENERIC_POPCOUNT
+#endif
+
+#ifdef NEED_GENERIC_POPCOUNT
+static inline
+unsigned int
+popcount_size_t_generic (size_t val)
+{
+    unsigned short j;
+    unsigned int count = 0;
+
+    for (j = 0; j < BITS_PER_SIZE_T; ++j)
+      count += !!((((size_t) 1) << j) & val);
+
+    return count;
+}
+#endif
+
+#ifdef USE_MSC_POPCOUNT
+static inline
+unsigned int
+popcount_size_t_msc (size_t val)
+{
+  unsigned int count;
+
+#pragma intrinsic __cpuid
+  /* While gcc falls back to its own generic code if the machine on
+     which it's running doesn't support popcount, we need to perform the
+     detection and fallback ourselves when compiling with Microsoft's
+     compiler.  */
+
+    static enum {
+      popcount_unknown_support,
+      popcount_use_generic,
+      popcount_use_intrinsic
+    } popcount_state;
+
+    if (popcount_state == popcount_unknown_support)
+      {
+        int cpu_info[4];
+        __cpuid (cpu_info, 1);
+        if (cpu_info[2] & (1<<23)) /* See MSDN.  */
+          popcount_state = popcount_use_intrinsic;
+        else
+          popcount_state = popcount_use_generic;
+      }
+
+    if (popcount_state == popcount_use_intrinsic)
+      {
+# if BITS_PER_SIZE_T == 64
+#  pragma intrinsic __popcnt64
+      count = __popcnt64 (val);
+# else
+#  pragma intrinsic __popcnt
+    count = __popcnt (val);
+# endif
+      }
+    else
+      count = popcount_size_t_generic (val);
+
+    return count;
+}
+#endif /* USE_MSC_POPCOUNT */
+
+#ifdef USE_GCC_POPCOUNT
+static inline
+unsigned int
+popcount_size_t_gcc (size_t val)
+{
+# if BITS_PER_SIZE_T == 64
+  return __builtin_popcountll (val);
+# else
+  return __builtin_popcount (val);
+# endif
+}
+#endif /* USE_GCC_POPCOUNT */
+
+static inline
+unsigned int
+popcount_size_t(size_t val)
+{
+#if defined USE_MSC_POPCOUNT
+  return popcount_size_t_msc (val);
+#elif defined USE_GCC_POPCOUNT
+  return popcount_size_t_gcc (val);
+#else
+  return popcount_size_t_generic (val);
+  #endif
+}
+
+enum bool_vector_op { bool_vector_exclusive_or,
+                      bool_vector_union,
+                      bool_vector_intersection,
+                      bool_vector_set_difference,
+                      bool_vector_subsetp };
+
+static inline
+Lisp_Object
+bool_vector_binop_driver (Lisp_Object op1,
+                          Lisp_Object op2,
+                          Lisp_Object dest,
+                          enum bool_vector_op op)
+{
+  EMACS_INT nr_bits;
+  size_t *adata, *bdata, *cdata;
+  ptrdiff_t i;
+  size_t changed = 0;
+  size_t mword;
+  ptrdiff_t nr_words;
+
+  CHECK_BOOL_VECTOR (op1);
+  CHECK_BOOL_VECTOR (op2);
+
+  nr_bits = min (XBOOL_VECTOR (op1)->size,
+                 XBOOL_VECTOR (op2)->size);
+
+  if (NILP (dest))
+    {
+      dest = Fmake_bool_vector (make_number (nr_bits), Qnil);
+      changed = 1;
+    }
+  else
+    {
+      CHECK_BOOL_VECTOR (dest);
+      nr_bits = min (nr_bits, XBOOL_VECTOR (dest)->size);
+    }
+
+  eassert_and_assume (nr_bits >= 0);
+  nr_words = ROUNDUP(nr_bits, BITS_PER_SIZE_T) / BITS_PER_SIZE_T;
+  
+  adata = (size_t*) XBOOL_VECTOR (dest)->data;
+  bdata = (size_t*) XBOOL_VECTOR (op1)->data;
+  cdata = (size_t*) XBOOL_VECTOR (op2)->data;
+  i = 0;
+  do
+    {
+      if (op == bool_vector_exclusive_or)
+        mword = bdata[i] ^ cdata[i];
+      else if (op == bool_vector_union || op == bool_vector_subsetp)
+        mword = bdata[i] | cdata[i];
+      else if (op == bool_vector_intersection)
+        mword = bdata[i] & cdata[i];
+      else if (op == bool_vector_set_difference)
+        mword = bdata[i] &~ cdata[i];
+      else
+        abort ();
+
+      changed |= adata[i] ^ mword;
+
+      if (op != bool_vector_subsetp)
+        adata[i] = mword;
+
+      i += 1;
+    }
+  while (i < nr_words);
+  return changed ? dest : Qnil;
+}
+
+/* Compute the number of trailing zero bits in val.  If val is zero,
+   return the number of bits in val.  */
+static inline
+unsigned int
+count_trailing_zero_bits (size_t val)
+{
+  if (val == 0)
+    return CHAR_BIT * sizeof (val);
+
+#if defined USE_GCC_POPCOUNT && BITS_PER_SIZE_T == 64
+  return __builtin_ctzll (val);
+#elif defined USE_GCC_POPCOUNT && BITS_PER_SIZE_T == 32
+  return __builtin_ctz (val);
+#elif __MSC_VER && BITS_PER_SIZE_T == 64
+# pragma intrinsic _BitScanForward64
+  {
+    /* No support test needed: support since 386.  */
+    unsigned long result;
+    _BitScanForward64 (&result, val);
+    return (unsigned int) result;
+  }
+#elif __MSC_VER && BITS_PER_SIZE_T == 32
+# pragma intrinsic _BitScanForward
+  {
+    /* No support test needed: support since 386.  */
+    unsigned long result;
+    _BitScanForward (&result, val);
+    return (unsigned int) result;
+  }
+#else
+  {
+    unsigned int count;
+    count = 0;
+    for(val = ~val; val & 1; val >>= 1)
+      ++count;
+
+    return count;
+  }
+#endif
+}
+
+static inline
+size_t
+size_t_to_host_endian (size_t val)
+{
+#ifdef WORDS_BIGENDIAN
+# if BITS_PER_SIZE_T == 64
+  return swap64 (val);
+# else
+  return swap32 (val);
+# endif
+#else
+  return val;
+#endif
+}
+
+DEFUN ("bool-vector-exclusive-or", Fbool_vector_exclusive_or,
+       Sbool_vector_exclusive_or, 2, 3, 0,
+       doc: /* Compute C = A ^ B, bitwise exclusive or.
+A, B, and C must be bool vectors.  If C is nil, allocate a new bool
+vector in which to store the result.  Return the destination vector if
+it changed or nil otherwise.  */
+       )
+  (Lisp_Object a, Lisp_Object b, Lisp_Object c)
+{
+  return bool_vector_binop_driver (a, b, c, bool_vector_exclusive_or);
+}
+
+DEFUN ("bool-vector-union", Fbool_vector_union,
+       Sbool_vector_union, 2, 3, 0,
+       doc: /* Compute C = A | B, bitwise or.
+A, B, and C must be bool vectors.  If C is nil, allocate a new bool
+vector in which to store the result.  Return the destination vector if
+it changed or nil otherwise.  */)
+  (Lisp_Object a, Lisp_Object b, Lisp_Object c)
+{
+  return bool_vector_binop_driver (a, b, c, bool_vector_union);
+}
+
+DEFUN ("bool-vector-intersection", Fbool_vector_intersection,
+       Sbool_vector_intersection, 2, 3, 0,
+       doc: /* Compute C = A & B, bitwise and.
+A, B, and C must be bool vectors.  If C is nil, allocate a new bool
+vector in which to store the result.  Return the destination vector if
+it changed or nil otherwise.  */)
+  (Lisp_Object a, Lisp_Object b, Lisp_Object c)
+{
+  return bool_vector_binop_driver (a, b, c, bool_vector_intersection);
+}
+
+DEFUN ("bool-vector-set-difference", Fbool_vector_set_difference,
+       Sbool_vector_set_difference, 2, 3, 0,
+       doc: /* Compute C = A &~ B, set difference.
+A, B, and C must be bool vectors.  If C is nil, allocate a new bool
+vector in which to store the result.  Return the destination vector if
+it changed or nil otherwise.  */)
+  (Lisp_Object a, Lisp_Object b, Lisp_Object c)
+{
+  return bool_vector_binop_driver (a, b, c, bool_vector_set_difference);
+}
+
+DEFUN ("bool-vector-subsetp", Fbool_vector_subsetp,
+       Sbool_vector_subsetp, 2, 2, 0,
+       doc: )
+  (Lisp_Object a, Lisp_Object b)
+{
+  /* Like bool_vector_union, but doesn't modify b.  */
+  return bool_vector_binop_driver (b, a, b, bool_vector_subsetp);
+}
+
+DEFUN ("bool-vector-not", Fbool_vector_not,
+       Sbool_vector_not, 1, 2, 0,
+       doc: /* Compute B = ~A.
+B must be a bool vector.  A must be a bool vector or nil.
+If A is nil, allocate a new bool vector in which to store the result.
+Return the destination vector.  */)
+  (Lisp_Object a, Lisp_Object b)
+{
+  EMACS_INT nr_bits;
+  size_t *bdata, *adata;
+  ptrdiff_t i;
+  size_t mword;
+
+  CHECK_BOOL_VECTOR (a);
+  nr_bits = XBOOL_VECTOR (a)->size;
+
+  if (NILP (b))
+    b = Fmake_bool_vector (make_number (nr_bits), Qnil);
+  else
+    {
+      CHECK_BOOL_VECTOR (b);
+      nr_bits = min (nr_bits, XBOOL_VECTOR (b)->size);
+    }
+
+  bdata = (size_t*) XBOOL_VECTOR (b)->data;
+  adata = (size_t*) XBOOL_VECTOR (a)->data;
+  i = 0;
+
+  eassert_and_assume (nr_bits >= 0);
+
+  while (i < nr_bits / BITS_PER_SIZE_T)
+    {
+      bdata[i] = ~adata[i];
+      i += 1;
+    }
+
+  if (nr_bits % BITS_PER_SIZE_T)
+    {
+      mword = size_t_to_host_endian (adata[i]);
+      mword = ~mword;
+      mword &= bool_vector_spare_mask (nr_bits);
+      bdata[i] = size_t_to_host_endian (mword);
+    }
+
+  return b;
+}
+
+DEFUN ("bool-vector-count-matches", Fbool_vector_count_matches,
+       Sbool_vector_count_matches, 2, 2, 0,
+       doc: /* Count how many elements in A equal B.
+A must be a bool vector. B is a generalized bool.  */)
+  (Lisp_Object a, Lisp_Object b)
+{
+  ptrdiff_t count;
+  EMACS_INT nr_bits;
+  size_t *adata;
+  size_t match;
+  ptrdiff_t i;
+
+  CHECK_BOOL_VECTOR (a);
+
+  nr_bits = XBOOL_VECTOR (a)->size;
+  count = 0;
+  match = NILP (b) ? (size_t) -1 : 0;
+  adata = (size_t*) XBOOL_VECTOR (a)->data;
+
+  eassert_and_assume (nr_bits >= 0);
+
+  for(i = 0; i < nr_bits / BITS_PER_SIZE_T; ++i)
+    count += popcount_size_t (adata[i] ^ match);
+
+  /* Mask out trailing parts of final mword.  */
+  if (nr_bits % BITS_PER_SIZE_T)
+    {
+      size_t mword = adata[i] ^ match;
+      mword = size_t_to_host_endian (mword);
+      count += popcount_size_t (mword & bool_vector_spare_mask (nr_bits));
+    }
+
+  return make_number (count);
+}
+
+DEFUN ("bool-vector-count-matches-at",
+       Fbool_vector_count_matches_at,
+       Sbool_vector_count_matches_at, 3, 3, 0,
+       doc: /* Count how many consecutive elements in A equal B at i.
+A must be a bool vector.  B is a generalized boolean.  i is an
+index into the vector.*/)
+  (Lisp_Object a, Lisp_Object b, Lisp_Object i)
+{
+  ptrdiff_t count;
+  EMACS_INT nr_bits;
+  ptrdiff_t offset;
+  size_t *adata;
+  size_t twiddle;
+  size_t mword; /* Machine word.  */
+  ptrdiff_t pos;
+  ptrdiff_t nr_words;
+
+  CHECK_BOOL_VECTOR (a);
+  CHECK_NATNUM (i);
+
+  nr_bits = XBOOL_VECTOR (a)->size;
+  if (XFASTINT (i) > nr_bits) /* Allow one past the end for convenience */
+    args_out_of_range (a, i);
+
+  adata = (size_t*) XBOOL_VECTOR (a)->data;
+
+  assume (nr_bits >= 0);
+  nr_words = ROUNDUP (nr_bits, BITS_PER_SIZE_T) / BITS_PER_SIZE_T;
+  
+  pos = XFASTINT (i) / BITS_PER_SIZE_T;
+  offset = XFASTINT (i) % BITS_PER_SIZE_T;
+  count = 0;
+
+  /* By XORing with twiddle, we transform the problem of "count
+     consecutive equal values" into "count the zero bits".  The latter
+     operation usually has hardware support.  */
+  twiddle = NILP (b) ? 0 : (size_t) -1;
+
+  /* Scan the remainder of the mword at the current offset.  */
+  if (pos < nr_words && offset != 0)
+    {
+      mword = size_t_to_host_endian (adata[pos]);
+      mword ^= twiddle;
+      mword >>= offset;
+      count = count_trailing_zero_bits (mword);
+      count = min (count, BITS_PER_SIZE_T - offset);
+      pos += 1;
+      if (count + offset < BITS_PER_SIZE_T)
+        return make_number (count);
+    }
+
+  /* Scan whole words until we either reach the end of the vector or
+     find an mword that doesn't completely match.  twiddle is
+     endian-independent.  */
+  while (pos < nr_words && adata[pos] == twiddle)
+    {
+      count += BITS_PER_SIZE_T;
+      ++pos;
+    }
+
+  if (pos < nr_words)
+    {
+      /* If we stopped because of a mismatch, see how many bits match
+         in the current mword.  */
+      mword = size_t_to_host_endian (adata[pos]);
+      mword ^= twiddle;
+      count += count_trailing_zero_bits (mword);
+    }
+  else if (nr_bits % BITS_PER_SIZE_T != 0)
+    {
+      /* If we hit the end, we might have overshot our count.  Reduce
+         the total by the number of spare bits at the end of the
+         vector.  */
+      count -= BITS_PER_SIZE_T - nr_bits % BITS_PER_SIZE_T;
+    }
+
+  return make_number (count);
+}
 
 
 void
@@ -3005,6 +3457,7 @@ syms_of_data (void)
   DEFSYM (Qsequencep, "sequencep");
   DEFSYM (Qbufferp, "bufferp");
   DEFSYM (Qvectorp, "vectorp");
+  DEFSYM (Qbool_vector_p, "bool-vector-p");
   DEFSYM (Qchar_or_string_p, "char-or-string-p");
   DEFSYM (Qmarkerp, "markerp");
   DEFSYM (Qbuffer_or_string_p, "buffer-or-string-p");
@@ -3222,6 +3675,15 @@ syms_of_data (void)
   defsubr (&Ssubr_arity);
   defsubr (&Ssubr_name);
 
+  defsubr (&Sbool_vector_exclusive_or);
+  defsubr (&Sbool_vector_union);
+  defsubr (&Sbool_vector_intersection);
+  defsubr (&Sbool_vector_set_difference);
+  defsubr (&Sbool_vector_not);
+  defsubr (&Sbool_vector_subsetp);
+  defsubr (&Sbool_vector_count_matches);
+  defsubr (&Sbool_vector_count_matches_at);
+
   set_symbol_function (Qwholenump, XSYMBOL (Qnatnump)->function);
 
   DEFVAR_LISP ("most-positive-fixnum", Vmost_positive_fixnum,