X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2FScalar-Vec-Util.git;a=blobdiff_plain;f=bitvect.h;h=207279f39afcf375074af5010042e37506be8f75;hp=b50c1a10407323cd5de02b6cfadeb9f5578045f7;hb=HEAD;hpb=228ef041cab8b2a0394a45029887c7eda2cc70ef

diff --git a/bitvect.h b/bitvect.h
index b50c1a1..207279f 100644
--- a/bitvect.h
+++ b/bitvect.h
@@ -5,17 +5,17 @@
 
 /* ... Generic macros ...................................................... */
 
-#define INLINE_DECLARE(P) STATIC P
+#define INLINE_DECLARE(P) static P
 #define INLINE_DEFINE
 
 #ifndef BV_UNIT
 # define BV_UNIT unsigned char
 #endif
 
-#define BV_SIZE(I) ((((I) % CHAR_BIT) != 0) + ((I) / CHAR_BIT))
-
 #define BITS(T) (CHAR_BIT * sizeof(T))
 
+#define BV_SIZE(I) (((((I) % BITS(BV_UNIT)) != 0) + ((I) / BITS(BV_UNIT))) * sizeof(BV_UNIT))
+
 /* 0 <= I <  CHAR_BIT * sizeof(T) */
 #define BV_MASK_LOWER(T, I)  (~((~((T) 0)) << (I)))
 /* 0 <  I <= CHAR_BIT * sizeof(T) */
@@ -332,6 +332,48 @@ INLINE_DECLARE(void bv_move(void *bv_, size_t ts, size_t fs, size_t l))
 #endif /* INLINE_DEFINE */
 #undef T
 
+/* ... Test if zero ........................................................ */
+
+#define T BV_UNIT
+INLINE_DECLARE(int bv_zero(const void *bv_, size_t s, size_t l))
+#ifdef INLINE_DEFINE
+{
+ size_t o;
+ T mask;
+ const T *bv = (const T *) bv_, *end;
+
+ bv += s / BITS(T);
+ o   = s % BITS(T);
+
+ mask = BV_MASK_HIGHER(T, BITS(T) - o);
+ if (o + l <= BITS(T)) {
+  if (o + l < BITS(T))
+   mask &= BV_MASK_LOWER(T, o + l);
+  if (*bv & mask)
+   return 0;
+ } else {
+  if (*bv & mask)
+   return 0;
+  ++bv;
+  l  -= (BITS(T) - o);
+  end = bv + l / BITS(T);
+  for (; bv < end; ++bv) {
+   if (*bv)
+    return 0;
+  }
+  o = l % BITS(T);
+  if (o) {
+   mask = BV_MASK_LOWER(T, o);
+   if (*bv & mask)
+    return 0;
+  }
+ }
+
+ return 1;
+}
+#endif /* INLINE_DEFINE */
+#undef T
+
 /* ... Compare ............................................................. */
 
 #define BV_EQ(T, B1, B2) \