f148af2593
Patch from Richard Purdie NWFPE used global variables which meant it wasn't safe for use with preemptive kernels. This patch removes them and communicates the information between functions in a preempt safe manner. Generation of some exceptions was broken and this has also been corrected. Tests with glibc's maths test suite show no change in the results before/after this patch. Signed-off-by: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
136 lines
3.3 KiB
C
136 lines
3.3 KiB
C
/*
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NetWinder Floating Point Emulator
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(c) Rebel.COM, 1998,1999
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(c) Philip Blundell, 2001
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Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include "fpa11.h"
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#include "fpopcode.h"
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#include "fpmodule.h"
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#include "fpmodule.inl"
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#include <linux/config.h>
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#include <linux/compiler.h>
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#include <linux/string.h>
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#include <asm/system.h>
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/* forward declarations */
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unsigned int EmulateCPDO(const unsigned int);
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unsigned int EmulateCPDT(const unsigned int);
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unsigned int EmulateCPRT(const unsigned int);
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/* Reset the FPA11 chip. Called to initialize and reset the emulator. */
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static void resetFPA11(void)
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{
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int i;
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FPA11 *fpa11 = GET_FPA11();
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/* initialize the register type array */
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for (i = 0; i <= 7; i++) {
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fpa11->fType[i] = typeNone;
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}
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/* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
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fpa11->fpsr = FP_EMULATOR | BIT_AC;
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}
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int8 SetRoundingMode(const unsigned int opcode)
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{
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switch (opcode & MASK_ROUNDING_MODE) {
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default:
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case ROUND_TO_NEAREST:
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return float_round_nearest_even;
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case ROUND_TO_PLUS_INFINITY:
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return float_round_up;
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case ROUND_TO_MINUS_INFINITY:
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return float_round_down;
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case ROUND_TO_ZERO:
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return float_round_to_zero;
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}
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}
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int8 SetRoundingPrecision(const unsigned int opcode)
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{
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#ifdef CONFIG_FPE_NWFPE_XP
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switch (opcode & MASK_ROUNDING_PRECISION) {
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case ROUND_SINGLE:
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return 32;
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case ROUND_DOUBLE:
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return 64;
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case ROUND_EXTENDED:
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return 80;
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default:
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return 80;
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}
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#endif
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return 80;
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}
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void nwfpe_init_fpa(union fp_state *fp)
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{
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FPA11 *fpa11 = (FPA11 *)fp;
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#ifdef NWFPE_DEBUG
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printk("NWFPE: setting up state.\n");
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#endif
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memset(fpa11, 0, sizeof(FPA11));
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resetFPA11();
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fpa11->initflag = 1;
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}
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/* Emulate the instruction in the opcode. */
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unsigned int EmulateAll(unsigned int opcode)
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{
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unsigned int code;
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#ifdef NWFPE_DEBUG
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printk("NWFPE: emulating opcode %08x\n", opcode);
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#endif
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code = opcode & 0x00000f00;
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if (code == 0x00000100 || code == 0x00000200) {
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/* For coprocessor 1 or 2 (FPA11) */
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code = opcode & 0x0e000000;
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if (code == 0x0e000000) {
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if (opcode & 0x00000010) {
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/* Emulate conversion opcodes. */
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/* Emulate register transfer opcodes. */
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/* Emulate comparison opcodes. */
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return EmulateCPRT(opcode);
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} else {
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/* Emulate monadic arithmetic opcodes. */
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/* Emulate dyadic arithmetic opcodes. */
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return EmulateCPDO(opcode);
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}
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} else if (code == 0x0c000000) {
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/* Emulate load/store opcodes. */
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/* Emulate load/store multiple opcodes. */
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return EmulateCPDT(opcode);
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}
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}
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/* Invalid instruction detected. Return FALSE. */
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return 0;
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}
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