/* $NetBSD: fpu.h,v 1.5 2008/04/16 21:51:03 cegger 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 { uint16_t fx_fcw; uint16_t fx_fsw; uint8_t fx_ftw; uint8_t fx_unused1; uint16_t fx_fop; uint64_t fx_rip; uint64_t fx_rdp; uint32_t fx_mxcsr; uint32_t fx_mxcsr_mask; uint64_t fx_st[8][2]; /* 8 normal FP regs */ uint64_t fx_xmm[16][2]; /* 16 SSE2 registers */ uint8_t fx_unused3[96]; } __packed; struct savefpu { struct fxsave64 fp_fxsave; /* see above */ uint16_t fp_ex_sw; /* saved status from last exception */ uint16_t fp_ex_tw; /* saved tag from last exception */ } __aligned(16); #ifdef _KERNEL /* * This one only used for backward compat coredumping. */ struct oldfsave { uint16_t fs_control; uint16_t fs_unused0; uint16_t fs_status; uint16_t fs_unused1; uint16_t fs_tag; uint16_t fs_unused2; uint32_t fs_ipoff; uint16_t fs_ipsel; uint16_t fs_op; uint32_t fs_opoff; uint16_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 *, bool); void fpusave_cpu(bool); #endif #endif /* _AMD64_FPU_H_ */