fpu.h revision 230269
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)npx.h 5.3 (Berkeley) 1/18/91 33 * $FreeBSD: head/sys/amd64/include/fpu.h 230269 2012-01-17 16:53:41Z kib $ 34 */ 35 36/* 37 * Floating Point Data Structures and Constants 38 * W. Jolitz 1/90 39 */ 40 41#ifndef _MACHINE_FPU_H_ 42#define _MACHINE_FPU_H_ 43 44/* Contents of each x87 floating point accumulator */ 45struct fpacc87 { 46 uint8_t fp_bytes[10]; 47}; 48 49/* Contents of each SSE extended accumulator */ 50struct xmmacc { 51 uint8_t xmm_bytes[16]; 52}; 53 54/* Contents of the upper 16 bytes of each AVX extended accumulator */ 55struct ymmacc { 56 uint8_t ymm_bytes[16]; 57}; 58 59struct envxmm { 60 uint16_t en_cw; /* control word (16bits) */ 61 uint16_t en_sw; /* status word (16bits) */ 62 uint8_t en_tw; /* tag word (8bits) */ 63 uint8_t en_zero; 64 uint16_t en_opcode; /* opcode last executed (11 bits ) */ 65 uint64_t en_rip; /* floating point instruction pointer */ 66 uint64_t en_rdp; /* floating operand pointer */ 67 uint32_t en_mxcsr; /* SSE sontorol/status register */ 68 uint32_t en_mxcsr_mask; /* valid bits in mxcsr */ 69}; 70 71struct savefpu { 72 struct envxmm sv_env; 73 struct { 74 struct fpacc87 fp_acc; 75 uint8_t fp_pad[6]; /* padding */ 76 } sv_fp[8]; 77 struct xmmacc sv_xmm[16]; 78 uint8_t sv_pad[96]; 79} __aligned(16); 80 81#ifdef _KERNEL 82struct fpu_kern_ctx { 83 struct savefpu hwstate; 84 struct savefpu *prev; 85 uint32_t flags; 86}; 87#define FPU_KERN_CTX_FPUINITDONE 0x01 88 89#define PCB_USER_FPU(pcb) (((pcb)->pcb_flags & PCB_KERNFPU) == 0) 90#endif 91 92/* 93 * The hardware default control word for i387's and later coprocessors is 94 * 0x37F, giving: 95 * 96 * round to nearest 97 * 64-bit precision 98 * all exceptions masked. 99 * 100 * FreeBSD/i386 uses 53 bit precision for things like fadd/fsub/fsqrt etc 101 * because of the difference between memory and fpu register stack arguments. 102 * If its using an intermediate fpu register, it has 80/64 bits to work 103 * with. If it uses memory, it has 64/53 bits to work with. However, 104 * gcc is aware of this and goes to a fair bit of trouble to make the 105 * best use of it. 106 * 107 * This is mostly academic for AMD64, because the ABI prefers the use 108 * SSE2 based math. For FreeBSD/amd64, we go with the default settings. 109 */ 110#define __INITIAL_FPUCW__ 0x037F 111#define __INITIAL_FPUCW_I386__ 0x127F 112#define __INITIAL_MXCSR__ 0x1F80 113#define __INITIAL_MXCSR_MASK__ 0xFFBF 114 115#ifdef _KERNEL 116void fpudna(void); 117void fpudrop(void); 118void fpuexit(struct thread *td); 119int fpuformat(void); 120int fpugetregs(struct thread *td); 121void fpuinit(void); 122void fpusetregs(struct thread *td, struct savefpu *addr); 123int fputrap(void); 124void fpuuserinited(struct thread *td); 125int fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx, 126 u_int flags); 127int fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx); 128int fpu_kern_thread(u_int flags); 129int is_fpu_kern_thread(u_int flags); 130 131/* 132 * Flags for fpu_kern_enter() and fpu_kern_thread(). 133 */ 134#define FPU_KERN_NORMAL 0x0000 135 136#endif 137 138#endif /* !_MACHINE_FPU_H_ */ 139