219 lines
7.2 KiB
C
219 lines
7.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*---------------------------------------------------------------------------+
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| fpu_emu.h |
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| Copyright (C) 1992,1993,1994,1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
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| Australia. E-mail billm@suburbia.net |
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+---------------------------------------------------------------------------*/
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#ifndef _FPU_EMU_H_
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#define _FPU_EMU_H_
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/*
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* Define PECULIAR_486 to get a closer approximation to 80486 behaviour,
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* rather than behaviour which appears to be cleaner.
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* This is a matter of opinion: for all I know, the 80486 may simply
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* be complying with the IEEE spec. Maybe one day I'll get to see the
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* spec...
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*/
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#define PECULIAR_486
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#ifdef __ASSEMBLY__
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#include "fpu_asm.h"
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#define Const(x) $##x
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#else
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#define Const(x) x
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#endif
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#define EXP_BIAS Const(0)
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#define EXP_OVER Const(0x4000) /* smallest invalid large exponent */
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#define EXP_UNDER Const(-0x3fff) /* largest invalid small exponent */
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#define EXP_WAY_UNDER Const(-0x6000) /* Below the smallest denormal, but
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still a 16 bit nr. */
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#define EXP_Infinity EXP_OVER
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#define EXP_NaN EXP_OVER
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#define EXTENDED_Ebias Const(0x3fff)
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#define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */
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#define SIGN_POS Const(0)
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#define SIGN_NEG Const(0x80)
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#define SIGN_Positive Const(0)
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#define SIGN_Negative Const(0x8000)
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/* Keep the order TAG_Valid, TAG_Zero, TW_Denormal */
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/* The following fold to 2 (Special) in the Tag Word */
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#define TW_Denormal Const(4) /* De-normal */
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#define TW_Infinity Const(5) /* + or - infinity */
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#define TW_NaN Const(6) /* Not a Number */
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#define TW_Unsupported Const(7) /* Not supported by an 80486 */
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#define TAG_Valid Const(0) /* valid */
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#define TAG_Zero Const(1) /* zero */
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#define TAG_Special Const(2) /* De-normal, + or - infinity,
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or Not a Number */
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#define TAG_Empty Const(3) /* empty */
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#define TAG_Error Const(0x80) /* probably need to abort */
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#define LOADED_DATA Const(10101) /* Special st() number to identify
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loaded data (not on stack). */
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/* A few flags (must be >= 0x10). */
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#define REV 0x10
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#define DEST_RM 0x20
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#define LOADED 0x40
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#define FPU_Exception Const(0x80000000) /* Added to tag returns. */
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#ifndef __ASSEMBLY__
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#include "fpu_system.h"
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#include <uapi/asm/sigcontext.h> /* for struct _fpstate */
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#include <asm/math_emu.h>
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#include <linux/linkage.h>
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/*
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#define RE_ENTRANT_CHECKING
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*/
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#ifdef RE_ENTRANT_CHECKING
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extern u_char emulating;
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# define RE_ENTRANT_CHECK_OFF emulating = 0
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# define RE_ENTRANT_CHECK_ON emulating = 1
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#else
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# define RE_ENTRANT_CHECK_OFF
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# define RE_ENTRANT_CHECK_ON
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#endif /* RE_ENTRANT_CHECKING */
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#define FWAIT_OPCODE 0x9b
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#define OP_SIZE_PREFIX 0x66
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#define ADDR_SIZE_PREFIX 0x67
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#define PREFIX_CS 0x2e
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#define PREFIX_DS 0x3e
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#define PREFIX_ES 0x26
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#define PREFIX_SS 0x36
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#define PREFIX_FS 0x64
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#define PREFIX_GS 0x65
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#define PREFIX_REPE 0xf3
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#define PREFIX_REPNE 0xf2
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#define PREFIX_LOCK 0xf0
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#define PREFIX_CS_ 1
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#define PREFIX_DS_ 2
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#define PREFIX_ES_ 3
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#define PREFIX_FS_ 4
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#define PREFIX_GS_ 5
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#define PREFIX_SS_ 6
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#define PREFIX_DEFAULT 7
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struct address {
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unsigned int offset;
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unsigned int selector:16;
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unsigned int opcode:11;
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unsigned int empty:5;
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};
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struct fpu__reg {
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unsigned sigl;
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unsigned sigh;
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short exp;
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};
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typedef void (*FUNC) (void);
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typedef struct fpu__reg FPU_REG;
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typedef void (*FUNC_ST0) (FPU_REG *st0_ptr, u_char st0_tag);
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typedef struct {
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u_char address_size, operand_size, segment;
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} overrides;
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/* This structure is 32 bits: */
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typedef struct {
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overrides override;
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u_char default_mode;
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} fpu_addr_modes;
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/* PROTECTED has a restricted meaning in the emulator; it is used
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to signal that the emulator needs to do special things to ensure
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that protection is respected in a segmented model. */
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#define PROTECTED 4
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#define SIXTEEN 1 /* We rely upon this being 1 (true) */
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#define VM86 SIXTEEN
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#define PM16 (SIXTEEN | PROTECTED)
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#define SEG32 PROTECTED
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extern u_char const data_sizes_16[32];
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#define register_base ((u_char *) registers )
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#define fpu_register(x) ( * ((FPU_REG *)( register_base + 10 * (x & 7) )) )
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#define st(x) ( * ((FPU_REG *)( register_base + 10 * ((top+x) & 7) )) )
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#define STACK_OVERFLOW (FPU_stackoverflow(&st_new_ptr))
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#define NOT_EMPTY(i) (!FPU_empty_i(i))
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#define NOT_EMPTY_ST0 (st0_tag ^ TAG_Empty)
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#define poppop() { FPU_pop(); FPU_pop(); }
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/* push() does not affect the tags */
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#define push() { top--; }
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#define signbyte(a) (((u_char *)(a))[9])
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#define getsign(a) (signbyte(a) & 0x80)
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#define setsign(a,b) { if ((b) != 0) signbyte(a) |= 0x80; else signbyte(a) &= 0x7f; }
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#define copysign(a,b) { if (getsign(a)) signbyte(b) |= 0x80; \
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else signbyte(b) &= 0x7f; }
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#define changesign(a) { signbyte(a) ^= 0x80; }
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#define setpositive(a) { signbyte(a) &= 0x7f; }
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#define setnegative(a) { signbyte(a) |= 0x80; }
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#define signpositive(a) ( (signbyte(a) & 0x80) == 0 )
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#define signnegative(a) (signbyte(a) & 0x80)
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static inline void reg_copy(FPU_REG const *x, FPU_REG *y)
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{
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*(short *)&(y->exp) = *(const short *)&(x->exp);
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*(long long *)&(y->sigl) = *(const long long *)&(x->sigl);
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}
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#define exponent(x) (((*(short *)&((x)->exp)) & 0x7fff) - EXTENDED_Ebias)
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#define setexponentpos(x,y) { (*(short *)&((x)->exp)) = \
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((y) + EXTENDED_Ebias) & 0x7fff; }
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#define exponent16(x) (*(short *)&((x)->exp))
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#define setexponent16(x,y) { (*(short *)&((x)->exp)) = (u16)(y); }
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#define addexponent(x,y) { (*(short *)&((x)->exp)) += (y); }
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#define stdexp(x) { (*(short *)&((x)->exp)) += EXTENDED_Ebias; }
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#define isdenormal(ptr) (exponent(ptr) == EXP_BIAS+EXP_UNDER)
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#define significand(x) ( ((unsigned long long *)&((x)->sigl))[0] )
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/*----- Prototypes for functions written in assembler -----*/
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/* extern void reg_move(FPU_REG *a, FPU_REG *b); */
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asmlinkage int FPU_normalize(FPU_REG *x);
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asmlinkage int FPU_normalize_nuo(FPU_REG *x);
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asmlinkage int FPU_u_sub(FPU_REG const *arg1, FPU_REG const *arg2,
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FPU_REG * answ, unsigned int control_w, u_char sign,
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int expa, int expb);
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asmlinkage int FPU_u_mul(FPU_REG const *arg1, FPU_REG const *arg2,
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FPU_REG * answ, unsigned int control_w, u_char sign,
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int expon);
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asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2,
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FPU_REG * answ, unsigned int control_w, u_char sign);
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asmlinkage int FPU_u_add(FPU_REG const *arg1, FPU_REG const *arg2,
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FPU_REG * answ, unsigned int control_w, u_char sign,
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int expa, int expb);
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asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2,
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unsigned int control_w, u_char sign);
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asmlinkage unsigned FPU_shrx(void *l, unsigned x);
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asmlinkage unsigned FPU_shrxs(void *v, unsigned x);
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asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y);
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asmlinkage int FPU_round(FPU_REG *arg, unsigned int extent, int dummy,
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unsigned int control_w, u_char sign);
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#ifndef MAKING_PROTO
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#include "fpu_proto.h"
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#endif
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#endif /* __ASSEMBLY__ */
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#endif /* _FPU_EMU_H_ */
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