fpu.h revision 4fd606d1f5abe38e1f42c38de1d2e895166bd0f4
/* $NetBSD: fpu.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $ */
#ifndef _AMD64_FPU_H_
#define _AMD64_FPU_H_
/*
* NetBSD/amd64 only uses the extended save/restore format used
* by fxsave/fsrestore, to always deal with the SSE registers,
* which are part of the ABI to pass floating point values.
* Must be stored in memory on a 16-byte boundary.
*/
struct fxsave64 {
u_int16_t fx_fcw;
u_int16_t fx_fsw;
u_int8_t fx_ftw;
u_int8_t fx_unused1;
u_int16_t fx_fop;
u_int64_t fx_rip;
u_int64_t fx_rdp;
u_int32_t fx_mxcsr;
u_int32_t fx_mxcsr_mask;
u_int64_t fx_st[8][2]; /* 8 normal FP regs */
u_int64_t fx_xmm[16][2]; /* 16 SSE2 registers */
u_int8_t fx_unused3[96];
} __attribute__((packed));
struct savefpu {
struct fxsave64 fp_fxsave; /* see above */
u_int16_t fp_ex_sw; /* saved status from last exception */
u_int16_t fp_ex_tw; /* saved tag from last exception */
};
#ifdef _KERNEL
/*
* This one only used for backward compat coredumping.
*/
struct oldfsave {
u_int16_t fs_control;
u_int16_t fs_unused0;
u_int16_t fs_status;
u_int16_t fs_unused1;
u_int16_t fs_tag;
u_int16_t fs_unused2;
u_int32_t fs_ipoff;
u_int16_t fs_ipsel;
u_int16_t fs_op;
u_int32_t fs_opoff;
u_int16_t fs_opsel;
} __attribute__ ((packed));
#endif
/*
* The i387 defaults to Intel extended precision mode and round to nearest,
* with all exceptions masked.
*/
#define __INITIAL_NPXCW__ 0x037f
#define __INITIAL_MXCSR__ 0x1f80
#define __INITIAL_MXCSR_MASK__ 0xffbf
/* NetBSD uses IEEE double precision. */
#define __NetBSD_NPXCW__ 0x127f
/* Linux just uses the default control word. */
#define __Linux_NPXCW__ 0x037f
/*
* The standard control word from finit is 0x37F, giving:
* round to nearest
* 64-bit precision
* all exceptions masked.
*
* Now we want:
* affine mode (if we decide to support 287's)
* round to nearest
* 53-bit precision
* all exceptions masked.
*
* 64-bit precision often gives bad results with high level languages
* because it makes the results of calculations depend on whether
* intermediate values are stored in memory or in FPU registers.
*/
#ifdef _KERNEL
/*
* XXX
*/
struct trapframe;
struct cpu_info;
void fpuinit(struct cpu_info *);
void fpudrop(void);
void fpusave(struct lwp *);
void fpudiscard(struct lwp *);
void fputrap(struct trapframe *);
void fpusave_lwp(struct lwp *, int);
void fpusave_cpu(struct cpu_info *, int);
#endif
#endif /* _AMD64_FPU_H_ */