// SPDX-License-Identifier: GPL-2.0-or-later
/*
    NetWinder Floating Point Emulator
    (c) Rebel.COM, 1998,1999
    (c) Philip Blundell, 2001

    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>

*/

#include "fpa11.h"
#include "fpopcode.h"

#include "fpmodule.h"
#include "fpmodule.inl"

#include <linux/compiler.h>
#include <linux/string.h>

/* Reset the FPA11 chip.  Called to initialize and reset the emulator. */
static void resetFPA11(void)
{
        int i;
        FPA11 *fpa11 = GET_FPA11();

        /* initialize the register type array */
        for (i = 0; i <= 7; i++) {
                fpa11->fType[i] = typeNone;
        }

        /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
        fpa11->fpsr = FP_EMULATOR | BIT_AC;
}

int8 SetRoundingMode(const unsigned int opcode)
{
        switch (opcode & MASK_ROUNDING_MODE) {
        default:
        case ROUND_TO_NEAREST:
                return float_round_nearest_even;

        case ROUND_TO_PLUS_INFINITY:
                return float_round_up;

        case ROUND_TO_MINUS_INFINITY:
                return float_round_down;

        case ROUND_TO_ZERO:
                return float_round_to_zero;
        }
}

int8 SetRoundingPrecision(const unsigned int opcode)
{
#ifdef CONFIG_FPE_NWFPE_XP
        switch (opcode & MASK_ROUNDING_PRECISION) {
        case ROUND_SINGLE:
                return 32;

        case ROUND_DOUBLE:
                return 64;

        case ROUND_EXTENDED:
                return 80;

        default:
                return 80;
        }
#endif
        return 80;
}

void nwfpe_init_fpa(union fp_state *fp)
{
        FPA11 *fpa11 = (FPA11 *)fp;
#ifdef NWFPE_DEBUG
        printk("NWFPE: setting up state.\n");
#endif
        memset(fpa11, 0, sizeof(FPA11));
        resetFPA11();
        fpa11->initflag = 1;
}

/* Emulate the instruction in the opcode. */
unsigned int EmulateAll(unsigned int opcode)
{
        unsigned int code;

#ifdef NWFPE_DEBUG
        printk("NWFPE: emulating opcode %08x\n", opcode);
#endif
        code = opcode & 0x00000f00;
        if (code == 0x00000100 || code == 0x00000200) {
                /* For coprocessor 1 or 2 (FPA11) */
                code = opcode & 0x0e000000;
                if (code == 0x0e000000) {
                        if (opcode & 0x00000010) {
                                /* Emulate conversion opcodes. */
                                /* Emulate register transfer opcodes. */
                                /* Emulate comparison opcodes. */
                                return EmulateCPRT(opcode);
                        } else {
                                /* Emulate monadic arithmetic opcodes. */
                                /* Emulate dyadic arithmetic opcodes. */
                                return EmulateCPDO(opcode);
                        }
                } else if (code == 0x0c000000) {
                        /* Emulate load/store opcodes. */
                        /* Emulate load/store multiple opcodes. */
                        return EmulateCPDT(opcode);
                }
        }

        /* Invalid instruction detected.  Return FALSE. */
        return 0;
}