fpopcode.h

linux 内核源代码

/*
    NetWinder Floating Point Emulator
    (c) Rebel.COM, 1998,1999
    (c) Philip Blundell, 2001

    Direct questions, comments to Scott Bambrough <[e-mail]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#ifndef __FPOPCODE_H__
#define __FPOPCODE_H__


/*
ARM Floating Point Instruction Classes
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 
|c o n d|1 1 0 P|U|u|W|L|   Rn  |v|  Fd |0|0|0|1|  o f f s e t  | CPDT
|c o n d|1 1 0 P|U|w|W|L|   Rn  |x|  Fd |0|0|1|0|  o f f s e t  | CPDT (copro 2)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 
|c o n d|1 1 1 0|a|b|c|d|e|  Fn |j|  Fd |0|0|0|1|f|g|h|0|i|  Fm | CPDO
|c o n d|1 1 1 0|a|b|c|L|e|  Fn |   Rd  |0|0|0|1|f|g|h|1|i|  Fm | CPRT
|c o n d|1 1 1 0|a|b|c|1|e|  Fn |1|1|1|1|0|0|0|1|f|g|h|1|i|  Fm | comparisons
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 

CPDT		data transfer instructions
		LDF, STF, LFM (copro 2), SFM (copro 2)
		
CPDO		dyadic arithmetic instructions
		ADF, MUF, SUF, RSF, DVF, RDF,
		POW, RPW, RMF, FML, FDV, FRD, POL

CPDO		monadic arithmetic instructions
		MVF, MNF, ABS, RND, SQT, LOG, LGN, EXP,
		SIN, COS, TAN, ASN, ACS, ATN, URD, NRM
		
CPRT		joint arithmetic/data transfer instructions
		FIX (arithmetic followed by load/store)
		FLT (load/store followed by arithmetic)
		CMF, CNF CMFE, CNFE (comparisons)
		WFS, RFS (write/read floating point status register)
		WFC, RFC (write/read floating point control register)

cond		condition codes
P		pre/post index bit: 0 = postindex, 1 = preindex
U		up/down bit: 0 = stack grows down, 1 = stack grows up
W		write back bit: 1 = update base register (Rn)
L		load/store bit: 0 = store, 1 = load
Rn		base register
Rd		destination/source register		
Fd		floating point destination register
Fn		floating point source register
Fm		floating point source register or floating point constant

uv		transfer length (TABLE 1)
wx		register count (TABLE 2)
abcd		arithmetic opcode (TABLES 3 & 4)
ef		destination size (rounding precision) (TABLE 5)
gh		rounding mode (TABLE 6)
j		dyadic/monadic bit: 0 = dyadic, 1 = monadic
i 		constant bit: 1 = constant (TABLE 6)
*/

/*
TABLE 1
+-------------------------+---+---+---------+---------+
|  Precision              | u | v | FPSR.EP | length  |
+-------------------------+---+---+---------+---------+
| Single                  | 0 | 0 |    x    | 1 words |
| Double                  | 1 | 1 |    x    | 2 words |
| Extended                | 1 | 1 |    x    | 3 words |
| Packed decimal          | 1 | 1 |    0    | 3 words |
| Expanded packed decimal | 1 | 1 |    1    | 4 words |
+-------------------------+---+---+---------+---------+
Note: x = don't care
*/

/*
TABLE 2
+---+---+---------------------------------+
| w | x | Number of registers to transfer |
+---+---+---------------------------------+
| 0 | 1 |  1                              |
| 1 | 0 |  2                              |
| 1 | 1 |  3                              |
| 0 | 0 |  4                              |
+---+---+---------------------------------+
*/

/*
TABLE 3: Dyadic Floating Point Opcodes
+---+---+---+---+----------+-----------------------+-----------------------+
| a | b | c | d | Mnemonic | Description           | Operation             |
+---+---+---+---+----------+-----------------------+-----------------------+
| 0 | 0 | 0 | 0 | ADF      | Add                   | Fd := Fn + Fm         |
| 0 | 0 | 0 | 1 | MUF      | Multiply              | Fd := Fn * Fm         |
| 0 | 0 | 1 | 0 | SUF      | Subtract              | Fd := Fn - Fm         |
| 0 | 0 | 1 | 1 | RSF      | Reverse subtract      | Fd := Fm - Fn         |
| 0 | 1 | 0 | 0 | DVF      | Divide                | Fd := Fn / Fm         |
| 0 | 1 | 0 | 1 | RDF      | Reverse divide        | Fd := Fm / Fn         |
| 0 | 1 | 1 | 0 | POW      | Power                 | Fd := Fn ^ Fm         |
| 0 | 1 | 1 | 1 | RPW      | Reverse power         | Fd := Fm ^ Fn         |
| 1 | 0 | 0 | 0 | RMF      | Remainder             | Fd := IEEE rem(Fn/Fm) |
| 1 | 0 | 0 | 1 | FML      | Fast Multiply         | Fd := Fn * Fm         |
| 1 | 0 | 1 | 0 | FDV      | Fast Divide           | Fd := Fn / Fm         |
| 1 | 0 | 1 | 1 | FRD      | Fast reverse divide   | Fd := Fm / Fn         |
| 1 | 1 | 0 | 0 | POL      | Polar angle (ArcTan2) | Fd := arctan2(Fn,Fm)  |
| 1 | 1 | 0 | 1 |          | undefined instruction | trap                  |
| 1 | 1 | 1 | 0 |          | undefined instruction | trap                  |
| 1 | 1 | 1 | 1 |          | undefined instruction | trap                  |
+---+---+---+---+----------+-----------------------+-----------------------+
Note: POW, RPW, POL are deprecated, and are available for backwards
      compatibility only.
*/

/*
TABLE 4: Monadic Floating Point Opcodes
+---+---+---+---+----------+-----------------------+-----------------------+
| a | b | c | d | Mnemonic | Description           | Operation             |
+---+---+---+---+----------+-----------------------+-----------------------+
| 0 | 0 | 0 | 0 | MVF      | Move                  | Fd := Fm              |
| 0 | 0 | 0 | 1 | MNF      | Move negated          | Fd := - Fm            |
| 0 | 0 | 1 | 0 | ABS      | Absolute value        | Fd := abs(Fm)         |
| 0 | 0 | 1 | 1 | RND      | Round to integer      | Fd := int(Fm)         |
| 0 | 1 | 0 | 0 | SQT      | Square root           | Fd := sqrt(Fm)        |
| 0 | 1 | 0 | 1 | LOG      | Log base 10           | Fd := log10(Fm)       |
| 0 | 1 | 1 | 0 | LGN      | Log base e            | Fd := ln(Fm)          |
| 0 | 1 | 1 | 1 | EXP      | Exponent              | Fd := e ^ Fm          |
| 1 | 0 | 0 | 0 | SIN      | Sine                  | Fd := sin(Fm)         |
| 1 | 0 | 0 | 1 | COS      | Cosine                | Fd := cos(Fm)         |
| 1 | 0 | 1 | 0 | TAN      | Tangent               | Fd := tan(Fm)         |
| 1 | 0 | 1 | 1 | ASN      | Arc Sine              | Fd := arcsin(Fm)      |
| 1 | 1 | 0 | 0 | ACS      | Arc Cosine            | Fd := arccos(Fm)      |
| 1 | 1 | 0 | 1 | ATN      | Arc Tangent           | Fd := arctan(Fm)      |
| 1 | 1 | 1 | 0 | URD      | Unnormalized round    | Fd := int(Fm)         |
| 1 | 1 | 1 | 1 | NRM      | Normalize             | Fd := norm(Fm)        |
+---+---+---+---+----------+-----------------------+-----------------------+
Note: LOG, LGN, EXP, SIN, COS, TAN, ASN, ACS, ATN are deprecated, and are
      available for backwards compatibility only.
*/

/*
TABLE 5
+-------------------------+---+---+
|  Rounding Precision     | e | f |
+-------------------------+---+---+
| IEEE Single precision   | 0 | 0 |
| IEEE Double precision   | 0 | 1 |
| IEEE Extended precision | 1 | 0 |
| undefined (trap)        | 1 | 1 |
+-------------------------+---+---+
*/

/*
TABLE 5
+---------------------------------+---+---+
|  Rounding Mode                  | g | h |
+---------------------------------+---+---+
| Round to nearest (default)      | 0 | 0 |
| Round toward plus infinity      | 0 | 1 |
| Round toward negative infinity  | 1 | 0 |
| Round toward zero               | 1 | 1 |
+---------------------------------+---+---+
*/

/*
===
=== Definitions for load and store instructions
===
*/

/* bit masks */
#define BIT_PREINDEX	0x01000000
#define BIT_UP		0x00800000
#define BIT_WRITE_BACK	0x00200000
#define BIT_LOAD	0x00100000

/* masks for load/store */
#define MASK_CPDT		0x0c000000	/* data processing opcode */
#define MASK_OFFSET		0x000000ff
#define MASK_TRANSFER_LENGTH	0x00408000
#define MASK_REGISTER_COUNT	MASK_TRANSFER_LENGTH
#define MASK_COPROCESSOR	0x00000f00

/* Tests for transfer length */
#define TRANSFER_SINGLE		0x00000000
#define TRANSFER_DOUBLE		0x00008000
#define TRANSFER_EXTENDED	0x00400000
#define TRANSFER_PACKED		MASK_TRANSFER_LENGTH

/* Get the coprocessor number from the opcode. */
#define getCoprocessorNumber(opcode)	((opcode & MASK_COPROCESSOR) >> 8)

/* Get the offset from the opcode. */
#define getOffset(opcode)		(opcode & MASK_OFFSET)

/* Tests for specific data transfer load/store opcodes. */
#define TEST_OPCODE(opcode,mask)	(((opcode) & (mask)) == (mask))

#define LOAD_OP(opcode)   TEST_OPCODE((opcode),MASK_CPDT | BIT_LOAD)
#define STORE_OP(opcode)  ((opcode & (MASK_CPDT | BIT_LOAD)) == MASK_CPDT)

#define LDF_OP(opcode)	(LOAD_OP(opcode) && (getCoprocessorNumber(opcode) == 1))
#define LFM_OP(opcode)	(LOAD_OP(opcode) && (getCoprocessorNumber(opcode) == 2))
#define STF_OP(opcode)	(STORE_OP(opcode) && (getCoprocessorNumber(opcode) == 1))
#define SFM_OP(opcode)	(STORE_OP(opcode) && (getCoprocessorNumber(opcode) == 2))

#define PREINDEXED(opcode)		((opcode & BIT_PREINDEX) != 0)
#define POSTINDEXED(opcode)		((opcode & BIT_PREINDEX) == 0)
#define BIT_UP_SET(opcode)		((opcode & BIT_UP) != 0)
#define BIT_UP_CLEAR(opcode)		((opcode & BIT_DOWN) == 0)
#define WRITE_BACK(opcode)		((opcode & BIT_WRITE_BACK) != 0)
#define LOAD(opcode)			((opcode & BIT_LOAD) != 0)
#define STORE(opcode)			((opcode & BIT_LOAD) == 0)

/*
===
=== Definitions for arithmetic instructions
===
*/
/* bit masks */
#define BIT_MONADIC	0x00008000
#define BIT_CONSTANT	0x00000008

#define CONSTANT_FM(opcode)		((opcode & BIT_CONSTANT) != 0)
#define MONADIC_INSTRUCTION(opcode)	((opcode & BIT_MONADIC) != 0)

/* instruction identification masks */
#define MASK_CPDO		0x0e000000	/* arithmetic opcode */
#define MASK_ARITHMETIC_OPCODE	0x00f08000
#define MASK_DESTINATION_SIZE	0x00080080