xref: /openbmc/linux/arch/mips/include/asm/div64.h (revision 25ab14cb)
1 /*
2  * Copyright (C) 2000, 2004, 2021  Maciej W. Rozycki
3  * Copyright (C) 2003, 07 Ralf Baechle (ralf@linux-mips.org)
4  *
5  * This file is subject to the terms and conditions of the GNU General Public
6  * License.  See the file "COPYING" in the main directory of this archive
7  * for more details.
8  */
9 #ifndef __ASM_DIV64_H
10 #define __ASM_DIV64_H
11 
12 #include <asm/bitsperlong.h>
13 
14 #if BITS_PER_LONG == 32
15 
16 /*
17  * No traps on overflows for any of these...
18  */
19 
20 #define do_div64_32(res, high, low, base) ({				\
21 	unsigned long __cf, __tmp, __tmp2, __i;				\
22 	unsigned long __quot32, __mod32;				\
23 									\
24 	__asm__(							\
25 	"	.set	push					\n"	\
26 	"	.set	noat					\n"	\
27 	"	.set	noreorder				\n"	\
28 	"	move	%2, $0					\n"	\
29 	"	move	%3, $0					\n"	\
30 	"	b	1f					\n"	\
31 	"	 li	%4, 0x21				\n"	\
32 	"0:							\n"	\
33 	"	sll	$1, %0, 0x1				\n"	\
34 	"	srl	%3, %0, 0x1f				\n"	\
35 	"	or	%0, $1, %5				\n"	\
36 	"	sll	%1, %1, 0x1				\n"	\
37 	"	sll	%2, %2, 0x1				\n"	\
38 	"1:							\n"	\
39 	"	bnez	%3, 2f					\n"	\
40 	"	 sltu	%5, %0, %z6				\n"	\
41 	"	bnez	%5, 3f					\n"	\
42 	"2:							\n"	\
43 	"	 addiu	%4, %4, -1				\n"	\
44 	"	subu	%0, %0, %z6				\n"	\
45 	"	addiu	%2, %2, 1				\n"	\
46 	"3:							\n"	\
47 	"	bnez	%4, 0b					\n"	\
48 	"	 srl	%5, %1, 0x1f				\n"	\
49 	"	.set	pop"						\
50 	: "=&r" (__mod32), "=&r" (__tmp),				\
51 	  "=&r" (__quot32), "=&r" (__cf),				\
52 	  "=&r" (__i), "=&r" (__tmp2)					\
53 	: "Jr" (base), "0" (high), "1" (low));				\
54 									\
55 	(res) = __quot32;						\
56 	__mod32;							\
57 })
58 
59 #define __div64_32(n, base) ({						\
60 	unsigned long __upper, __low, __high, __radix;			\
61 	unsigned long long __quot;					\
62 	unsigned long long __div;					\
63 	unsigned long __mod;						\
64 									\
65 	__div = (*n);							\
66 	__radix = (base);						\
67 									\
68 	__high = __div >> 32;						\
69 	__low = __div;							\
70 									\
71 	if (__high < __radix) {						\
72 		__upper = __high;					\
73 		__high = 0;						\
74 	} else {							\
75 		__upper = __high % __radix;				\
76 		__high /= __radix;					\
77 	}								\
78 									\
79 	__mod = do_div64_32(__low, __upper, __low, __radix);		\
80 									\
81 	__quot = __high;						\
82 	__quot = __quot << 32 | __low;					\
83 	(*n) = __quot;							\
84 	__mod;								\
85 })
86 
87 #endif /* BITS_PER_LONG == 32 */
88 
89 #include <asm-generic/div64.h>
90 
91 #endif /* __ASM_DIV64_H */
92