1 files changed, 25 insertions, 0 deletions
diff --git a/Carpet/CarpetReduce/src/bits.h b/Carpet/CarpetReduce/src/bits.h
new file mode 100644
index 000000000..65bd450da
--- /dev/null
+++ b/Carpet/CarpetReduce/src/bits.h
@@ -0,0 +1,25 @@
+#ifndef BITS_H
+#define BITS_H
+
+/* a mask with exactly bit n set */
+#define BMSK(n)   (1U << (n))
+
+/* whether bit n in value v is set */
+#define BGET(v,n) (!!((v) & BMSK(n)))
+
+/* set, clear, or invert bit n in value v */
+#define BSET(v,n) ((v) |  BMSK(n))
+#define BCLR(v,n) ((v) & ~BMSK(n))
+#define BINV(v,n) ((v) ^  BMSK(n))
+
+/* set bit n in value v to b */
+#define BCPY(v,b,n) ((b) ? BSET(v,n) : BCLR(v,n))
+
+/* count the number of set bits */
+#define BCNT(x) (((BX_(x)+(BX_(x)>>4)) & 0x0F0F0F0F) % 0xFF)
+#define BX_(x)  ((x)                                            \
+                 - (((x)>>1)&0x77777777)                        \
+                 - (((x)>>2)&0x33333333)                        \
+                 - (((x)>>3)&0x11111111))
+
+#endif  /* #ifndef BITS_H */