libfrog: move 64-bit division wrappers to libfrog

[thirdparty/xfsprogs-dev.git] / libfrog / div64.h

diff --git a/libfrog/div64.h b/libfrog/div64.h
new file mode 100644 (file)
index 0000000..673b01c
--- /dev/null
+++ b/libfrog/div64.h
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#ifndef LIBFROG_DIV64_H_
+#define LIBFROG_DIV64_H_
+
+static inline int __do_div(unsigned long long *n, unsigned base)
+{
+       int __res;
+       __res = (int)(((unsigned long) *n) % (unsigned) base);
+       *n = ((unsigned long) *n) / (unsigned) base;
+       return __res;
+}
+
+#define do_div(n,base) (__do_div((unsigned long long *)&(n), (base)))
+#define do_mod(a, b)           ((a) % (b))
+#define rol32(x,y)             (((x) << (y)) | ((x) >> (32 - (y))))
+
+/**
+ * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 32bit divisor
+ * @remainder: pointer to unsigned 32bit remainder
+ *
+ * Return: sets ``*remainder``, then returns dividend / divisor
+ *
+ * This is commonly provided by 32bit archs to provide an optimized 64bit
+ * divide.
+ */
+static inline uint64_t
+div_u64_rem(uint64_t dividend, uint32_t divisor, uint32_t *remainder)
+{
+       *remainder = dividend % divisor;
+       return dividend / divisor;
+}
+
+/**
+ * div_u64 - unsigned 64bit divide with 32bit divisor
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 32bit divisor
+ *
+ * This is the most common 64bit divide and should be used if possible,
+ * as many 32bit archs can optimize this variant better than a full 64bit
+ * divide.
+ */
+static inline uint64_t div_u64(uint64_t dividend, uint32_t divisor)
+{
+       uint32_t remainder;
+       return div_u64_rem(dividend, divisor, &remainder);
+}
+
+/**
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 64bit divisor
+ * @remainder: pointer to unsigned 64bit remainder
+ *
+ * Return: sets ``*remainder``, then returns dividend / divisor
+ */
+static inline uint64_t
+div64_u64_rem(uint64_t dividend, uint64_t divisor, uint64_t *remainder)
+{
+       *remainder = dividend % divisor;
+       return dividend / divisor;
+}
+
+static inline uint64_t rounddown_64(uint64_t x, uint32_t y)
+{
+       do_div(x, y);
+       return x * y;
+}
+
+static inline bool isaligned_64(uint64_t x, uint32_t y)
+{
+       return do_div(x, y) == 0;
+}
+
+static inline uint64_t
+roundup_64(uint64_t x, uint32_t y)
+{
+       x += y - 1;
+       do_div(x, y);
+       return x * y;
+}
+
+static inline uint64_t
+howmany_64(uint64_t x, uint32_t y)
+{
+       x += y - 1;
+       do_div(x, y);
+       return x;
+}
+
+#endif /* LIBFROG_DIV64_H_ */