64-bit bitwise manipulation functions, by Gautam Tirumala.

lib/libc/other/u64util.c

@@ -0,0 +1,76 @@
+/* Few u64 utils implemented in C
+ * Author: Gautam BT
+ */
+#include <minix/u64.h>
+
+u64_t rrotate64(u64_t x, unsigned short b)
+{
+	u64_t r, t;
+
+	b %= 64;
+
+	if(b == 32) {
+		r.lo = x.hi;
+		r.hi = x.lo;
+		return r;
+	}else if(b < 32) {
+		r.lo = (x.lo >> b) | (x.hi << (32 - b));		
+		r.hi = (x.hi >> b) | (x.lo << (32 - b));		
+		return r;
+	}else {
+		/* Rotate by 32 bits first then rotate by remaining */
+		t.lo = x.hi;
+		t.hi = x.lo;
+		b = b - 32;
+		r.lo = (t.lo >> b) | (t.hi << (32 - b));		
+		r.hi = (t.hi >> b) | (t.lo << (32 - b));		
+		return r;
+	}
+}
+
+u64_t rshift64(u64_t x, unsigned short b)
+{
+	u64_t r;
+
+	if(b >= 64)
+		return make64(0,0);
+
+	if(b >= 32) {
+		r.hi = 0;
+		r.lo = x.hi >> (b - 32);
+	}else {
+		r.lo = (x.lo >> b) | (x.hi << (32 - b));		
+		r.hi = (x.hi >> b);		
+	}
+	return r;
+}
+
+u64_t xor64(u64_t a, u64_t b)
+{
+	u64_t r;
+	r.hi = a.hi ^ b.hi;
+	r.lo = a.lo ^ b.lo;
+
+	return r;
+}
+
+u64_t and64(u64_t a, u64_t b)
+{
+	u64_t r;
+	r.hi = a.hi & b.hi;
+	r.lo = a.lo & b.lo;
+
+	return r;
+}
+
+u64_t not64(u64_t a)
+{
+	u64_t r;
+
+	r.hi = ~a.hi;
+	r.lo = ~a.lo;
+
+	return r;
+}
+
+