5b9f8ddbbd
AMD64, gcc (and the ABI) expects the x87 unit to be running in 80/64 mode (not 64/53) so that it can use it for 'long double' operations. It takes the expected precision differences into account when generating code.
115 lines
4.0 KiB
C
115 lines
4.0 KiB
C
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)npx.h 5.3 (Berkeley) 1/18/91
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* $FreeBSD$
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*/
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/*
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* 287/387 NPX Coprocessor Data Structures and Constants
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* W. Jolitz 1/90
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*/
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#ifndef _MACHINE_NPX_H_
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#define _MACHINE_NPX_H_
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/* Contents of each x87 floating point accumulator */
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struct fpacc87 {
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u_char fp_bytes[10];
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};
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/* Contents of each SSE extended accumulator */
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struct xmmacc {
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u_char xmm_bytes[16];
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};
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struct envxmm {
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u_int16_t en_cw; /* control word (16bits) */
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u_int16_t en_sw; /* status word (16bits) */
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u_int8_t en_tw; /* tag word (8bits) */
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u_int8_t en_zero;
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u_int16_t en_opcode; /* opcode last executed (11 bits ) */
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u_int64_t en_rip; /* floating point instruction pointer */
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u_int64_t en_rdp; /* floating operand pointer */
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u_int32_t en_mxcsr; /* SSE sontorol/status register */
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u_int32_t en_mxcsr_mask; /* valid bits in mxcsr */
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};
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struct savefpu {
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struct envxmm sv_env;
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struct {
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struct fpacc87 fp_acc;
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u_char fp_pad[6]; /* padding */
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} sv_fp[8];
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struct xmmacc sv_xmm[16];
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u_char sv_pad[96];
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} __aligned(16);
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/*
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* The hardware default control word for i387's and later coprocessors is
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* 0x37F, giving:
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*
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* round to nearest
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* 64-bit precision
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* all exceptions masked.
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*
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* FreeBSD/i386 uses 53 bit precision for things like fadd/fsub/fsqrt etc
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* because of the difference between memory and fpu register stack arguments.
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* If its using an intermediate fpu register, it has 80/64 bits to work
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* with. If it uses memory, it has 64/53 bits to work with. However,
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* gcc is aware of this and goes to a fair bit of trouble to make the
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* best use of it.
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*
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* This is mostly academic for AMD64, because the ABI prefers the use
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* SSE2 based math. For FreeBSD/amd64, we go with the default settings.
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*/
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#define __INITIAL_NPXCW__ 0x037F
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#define __INITIAL_MXCSR__ 0x1F80
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#define __INITIAL_MXCSR_MASK__ 0xFFBF
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#ifdef _KERNEL
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int npxdna(void);
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void npxdrop(void);
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void npxexit(struct thread *td);
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int npxformat(void);
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int npxgetregs(struct thread *td, struct savefpu *addr);
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void npxinit(u_short control);
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void npxsave(struct savefpu *addr);
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void npxsetregs(struct thread *td, struct savefpu *addr);
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int npxtrap(void);
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#endif
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#endif /* !_MACHINE_NPX_H_ */
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