6f6d6a1a6a
Rename div64_64 to div64_u64 to make it consistent with the other divide functions, so it clearly includes the type of the divide. Move its definition to math64.h as currently no architecture overrides the generic implementation. They can still override it of course, but the duplicated declarations are avoided. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: Avi Kivity <avi@qumranet.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
79 lines
1.7 KiB
C
79 lines
1.7 KiB
C
#ifndef _ASM_X86_DIV64_H
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#define _ASM_X86_DIV64_H
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#ifdef CONFIG_X86_32
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#include <linux/types.h>
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/*
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* do_div() is NOT a C function. It wants to return
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* two values (the quotient and the remainder), but
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* since that doesn't work very well in C, what it
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* does is:
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*
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* - modifies the 64-bit dividend _in_place_
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* - returns the 32-bit remainder
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*
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* This ends up being the most efficient "calling
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* convention" on x86.
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*/
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#define do_div(n, base) \
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({ \
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unsigned long __upper, __low, __high, __mod, __base; \
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__base = (base); \
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asm("":"=a" (__low), "=d" (__high) : "A" (n)); \
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__upper = __high; \
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if (__high) { \
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__upper = __high % (__base); \
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__high = __high / (__base); \
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} \
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asm("divl %2":"=a" (__low), "=d" (__mod) \
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: "rm" (__base), "0" (__low), "1" (__upper)); \
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asm("":"=A" (n) : "a" (__low), "d" (__high)); \
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__mod; \
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})
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/*
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* (long)X = ((long long)divs) / (long)div
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* (long)rem = ((long long)divs) % (long)div
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*
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* Warning, this will do an exception if X overflows.
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*/
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#define div_long_long_rem(a, b, c) div_ll_X_l_rem(a, b, c)
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static inline long div_ll_X_l_rem(long long divs, long div, long *rem)
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{
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long dum2;
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asm("divl %2":"=a"(dum2), "=d"(*rem)
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: "rm"(div), "A"(divs));
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return dum2;
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}
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static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
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{
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union {
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u64 v64;
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u32 v32[2];
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} d = { dividend };
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u32 upper;
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upper = d.v32[1];
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d.v32[1] = 0;
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if (upper >= divisor) {
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d.v32[1] = upper / divisor;
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upper %= divisor;
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}
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asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
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"rm" (divisor), "0" (d.v32[0]), "1" (upper));
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return d.v64;
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}
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#define div_u64_rem div_u64_rem
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#else
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# include <asm-generic/div64.h>
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#endif /* CONFIG_X86_32 */
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#endif /* _ASM_X86_DIV64_H */
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