// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * Floating-point emulation code
 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
 */
/*
 * BEGIN_DESC
 *
 *  File:
 *      @(#)    pa/fp/fpudispatch.c             $Revision: 1.1 $
 *
 *  Purpose:
 *      <<please update with a synopsis of the functionality provided by this file>>
 *
 *  External Interfaces:
 *      <<the following list was autogenerated, please review>>
 *      emfpudispatch(ir, dummy1, dummy2, fpregs)
 *      fpudispatch(ir, excp_code, holder, fpregs)
 *
 *  Internal Interfaces:
 *      <<the following list was autogenerated, please review>>
 *      static u_int decode_06(u_int, u_int *)
 *      static u_int decode_0c(u_int, u_int, u_int, u_int *)
 *      static u_int decode_0e(u_int, u_int, u_int, u_int *)
 *      static u_int decode_26(u_int, u_int *)
 *      static u_int decode_2e(u_int, u_int *)
 *      static void update_status_cbit(u_int *, u_int, u_int, u_int)
 *
 *  Theory:
 *      <<please update with a overview of the operation of this file>>
 *
 * END_DESC
*/

#define FPUDEBUG 0

#include "float.h"
#include <linux/bug.h>
#include <linux/kernel.h>
#include <asm/processor.h>
/* #include <sys/debug.h> */
/* #include <machine/sys/mdep_private.h> */

#define COPR_INST 0x30000000

/*
 * definition of extru macro.  If pos and len are constants, the compiler
 * will generate an extru instruction when optimized
 */
#define extru(r,pos,len)        (((r) >> (31-(pos))) & (( 1 << (len)) - 1))
/* definitions of bit field locations in the instruction */
#define fpmajorpos 5
#define fpr1pos 10
#define fpr2pos 15
#define fptpos  31
#define fpsubpos 18
#define fpclass1subpos 16
#define fpclasspos 22
#define fpfmtpos 20
#define fpdfpos 18
#define fpnulpos 26
/*
 * the following are the extra bits for the 0E major op
 */
#define fpxr1pos 24
#define fpxr2pos 19
#define fpxtpos 25
#define fpxpos 23
#define fp0efmtpos 20
/*
 * the following are for the multi-ops
 */
#define fprm1pos 10
#define fprm2pos 15
#define fptmpos 31
#define fprapos 25
#define fptapos 20
#define fpmultifmt 26
/*
 * the following are for the fused FP instructions
 */
     /* fprm1pos 10 */
     /* fprm2pos 15 */
#define fpraupos 18
#define fpxrm2pos 19
     /* fpfmtpos 20 */
#define fpralpos 23
#define fpxrm1pos 24
     /* fpxtpos 25 */
#define fpfusedsubop 26
     /* fptpos  31 */

/*
 * offset to constant zero in the FP emulation registers
 */
#define fpzeroreg (32*sizeof(double)/sizeof(u_int))

/*
 * extract the major opcode from the instruction
 */
#define get_major(op) extru(op,fpmajorpos,6)
/*
 * extract the two bit class field from the FP instruction. The class is at bit
 * positions 21-22
 */
#define get_class(op) extru(op,fpclasspos,2)
/*
 * extract the 3 bit subop field.  For all but class 1 instructions, it is
 * located at bit positions 16-18
 */
#define get_subop(op) extru(op,fpsubpos,3)
/*
 * extract the 2 or 3 bit subop field from class 1 instructions.  It is located
 * at bit positions 15-16 (PA1.1) or 14-16 (PA2.0)
 */
#define get_subop1_PA1_1(op) extru(op,fpclass1subpos,2) /* PA89 (1.1) fmt */
#define get_subop1_PA2_0(op) extru(op,fpclass1subpos,3) /* PA 2.0 fmt */

/* definitions of unimplemented exceptions */
#define MAJOR_0C_EXCP   0x09
#define MAJOR_0E_EXCP   0x0b
#define MAJOR_06_EXCP   0x03
#define MAJOR_26_EXCP   0x23
#define MAJOR_2E_EXCP   0x2b
#define PA83_UNIMP_EXCP 0x01

/*
 * Special Defines for TIMEX specific code
 */

#define FPU_TYPE_FLAG_POS (EM_FPU_TYPE_OFFSET>>2)
#define TIMEX_ROLEX_FPU_MASK (TIMEX_EXTEN_FLAG|ROLEX_EXTEN_FLAG)

/*
 * Static function definitions
 */
#define _PROTOTYPES
#if defined(_PROTOTYPES) || defined(_lint)
static u_int decode_0c(u_int, u_int, u_int, u_int *);
static u_int decode_0e(u_int, u_int, u_int, u_int *);
static u_int decode_06(u_int, u_int *);
static u_int decode_26(u_int, u_int *);
static u_int decode_2e(u_int, u_int *);
static void update_status_cbit(u_int *, u_int, u_int, u_int);
#else /* !_PROTOTYPES&&!_lint */
static u_int decode_0c();
static u_int decode_0e();
static u_int decode_06();
static u_int decode_26();
static u_int decode_2e();
static void update_status_cbit();
#endif /* _PROTOTYPES&&!_lint */

#define VASSERT(x)

static void parisc_linux_get_fpu_type(u_int fpregs[])
{
        /* on pa-linux the fpu type is not filled in by the
         * caller; it is constructed here  
         */ 
        if (boot_cpu_data.cpu_type == pcxs)
                fpregs[FPU_TYPE_FLAG_POS] = TIMEX_EXTEN_FLAG;
        else if (boot_cpu_data.cpu_type == pcxt ||
                 boot_cpu_data.cpu_type == pcxt_)
                fpregs[FPU_TYPE_FLAG_POS] = ROLEX_EXTEN_FLAG;
        else if (boot_cpu_data.cpu_type >= pcxu)
                fpregs[FPU_TYPE_FLAG_POS] = PA2_0_FPU_FLAG;
}

/*
 * this routine will decode the excepting floating point instruction and
 * call the appropriate emulation routine.
 * It is called by decode_fpu with the following parameters:
 * fpudispatch(current_ir, unimplemented_code, 0, &Fpu_register)
 * where current_ir is the instruction to be emulated,
 * unimplemented_code is the exception_code that the hardware generated
 * and &Fpu_register is the address of emulated FP reg 0.
 */
u_int
fpudispatch(u_int ir, u_int excp_code, u_int holder, u_int fpregs[])
{
        u_int class, subop;
        u_int fpu_type_flags;

        /* All FP emulation code assumes that ints are 4-bytes in length */
        VASSERT(sizeof(int) == 4);

        parisc_linux_get_fpu_type(fpregs);

        fpu_type_flags=fpregs[FPU_TYPE_FLAG_POS];  /* get fpu type flags */

        class = get_class(ir);
        if (class == 1) {
                if  (fpu_type_flags & PA2_0_FPU_FLAG)
                        subop = get_subop1_PA2_0(ir);
                else
                        subop = get_subop1_PA1_1(ir);
        }
        else
                subop = get_subop(ir);

        if (FPUDEBUG) printk("class %d subop %d\n", class, subop);

        switch (excp_code) {
                case MAJOR_0C_EXCP:
                case PA83_UNIMP_EXCP:
                        return(decode_0c(ir,class,subop,fpregs));
                case MAJOR_0E_EXCP:
                        return(decode_0e(ir,class,subop,fpregs));
                case MAJOR_06_EXCP:
                        return(decode_06(ir,fpregs));
                case MAJOR_26_EXCP:
                        return(decode_26(ir,fpregs));
                case MAJOR_2E_EXCP:
                        return(decode_2e(ir,fpregs));
                default:
                        /* "crashme Night Gallery painting nr 2. (asm_crash.s).
                         * This was fixed for multi-user kernels, but
                         * workstation kernels had a panic here.  This allowed
                         * any arbitrary user to panic the kernel by executing
                         * setting the FP exception registers to strange values
                         * and generating an emulation trap.  The emulation and
                         * exception code must never be able to panic the
                         * kernel.
                         */
                        return(UNIMPLEMENTEDEXCEPTION);
        }
}

/*
 * this routine is called by $emulation_trap to emulate a coprocessor
 * instruction if one doesn't exist
 */
u_int
emfpudispatch(u_int ir, u_int dummy1, u_int dummy2, u_int fpregs[])
{
        u_int class, subop, major;
        u_int fpu_type_flags;

        /* All FP emulation code assumes that ints are 4-bytes in length */
        VASSERT(sizeof(int) == 4);

        fpu_type_flags=fpregs[FPU_TYPE_FLAG_POS];  /* get fpu type flags */

        major = get_major(ir);
        class = get_class(ir);
        if (class == 1) {
                if  (fpu_type_flags & PA2_0_FPU_FLAG)
                        subop = get_subop1_PA2_0(ir);
                else
                        subop = get_subop1_PA1_1(ir);
        }
        else
                subop = get_subop(ir);
        switch (major) {
                case 0x0C:
                        return(decode_0c(ir,class,subop,fpregs));
                case 0x0E:
                        return(decode_0e(ir,class,subop,fpregs));
                case 0x06:
                        return(decode_06(ir,fpregs));
                case 0x26:
                        return(decode_26(ir,fpregs));
                case 0x2E:
                        return(decode_2e(ir,fpregs));
                default:
                        return(PA83_UNIMP_EXCP);
        }
}
        

static u_int
decode_0c(u_int ir, u_int class, u_int subop, u_int fpregs[])
{
        u_int r1,r2,t;          /* operand register offsets */ 
        u_int fmt;              /* also sf for class 1 conversions */
        u_int  df;              /* for class 1 conversions */
        u_int *status;
        u_int retval, local_status;
        u_int fpu_type_flags;

        if (ir == COPR_INST) {
                fpregs[0] = EMULATION_VERSION << 11;
                return(NOEXCEPTION);
        }
        status = &fpregs[0];    /* fp status register */
        local_status = fpregs[0]; /* and local copy */
        r1 = extru(ir,fpr1pos,5) * sizeof(double)/sizeof(u_int);
        if (r1 == 0)            /* map fr0 source to constant zero */
                r1 = fpzeroreg;
        t = extru(ir,fptpos,5) * sizeof(double)/sizeof(u_int);
        if (t == 0 && class != 2)       /* don't allow fr0 as a dest */
                return(MAJOR_0C_EXCP);
        fmt = extru(ir,fpfmtpos,2);     /* get fmt completer */

        switch (class) {
            case 0:
                switch (subop) {
                        case 0: /* COPR 0,0 emulated above*/
                        case 1:
                                return(MAJOR_0C_EXCP);
                        case 2: /* FCPY */
                                switch (fmt) {
                                    case 2: /* illegal */
                                        return(MAJOR_0C_EXCP);
                                    case 3: /* quad */
                                        t &= ~3;  /* force to even reg #s */
                                        r1 &= ~3;
                                        fpregs[t+3] = fpregs[r1+3];
                                        fpregs[t+2] = fpregs[r1+2];
                                        fallthrough;
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        fpregs[t] = fpregs[r1];
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 3: /* FABS */
                                switch (fmt) {
                                    case 2: /* illegal */
                                        return(MAJOR_0C_EXCP);
                                    case 3: /* quad */
                                        t &= ~3;  /* force to even reg #s */
                                        r1 &= ~3;
                                        fpregs[t+3] = fpregs[r1+3];
                                        fpregs[t+2] = fpregs[r1+2];
                                        fallthrough;
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        /* copy and clear sign bit */
                                        fpregs[t] = fpregs[r1] & 0x7fffffff;
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 6: /* FNEG */
                                switch (fmt) {
                                    case 2: /* illegal */
                                        return(MAJOR_0C_EXCP);
                                    case 3: /* quad */
                                        t &= ~3;  /* force to even reg #s */
                                        r1 &= ~3;
                                        fpregs[t+3] = fpregs[r1+3];
                                        fpregs[t+2] = fpregs[r1+2];
                                        fallthrough;
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        /* copy and invert sign bit */
                                        fpregs[t] = fpregs[r1] ^ 0x80000000;
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 7: /* FNEGABS */
                                switch (fmt) {
                                    case 2: /* illegal */
                                        return(MAJOR_0C_EXCP);
                                    case 3: /* quad */
                                        t &= ~3;  /* force to even reg #s */
                                        r1 &= ~3;
                                        fpregs[t+3] = fpregs[r1+3];
                                        fpregs[t+2] = fpregs[r1+2];
                                        fallthrough;
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        /* copy and set sign bit */
                                        fpregs[t] = fpregs[r1] | 0x80000000;
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 4: /* FSQRT */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fsqrt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fsqrt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2:
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 5: /* FRND */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_frnd(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_frnd(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2:
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                } /* end of switch (subop) */
                BUG();
        case 1: /* class 1 */
                df = extru(ir,fpdfpos,2); /* get dest format */
                if ((df & 2) || (fmt & 2)) {
                        /*
                         * fmt's 2 and 3 are illegal of not implemented
                         * quad conversions
                         */
                        return(MAJOR_0C_EXCP);
                }
                /*
                 * encode source and dest formats into 2 bits.
                 * high bit is source, low bit is dest.
                 * bit = 1 --> double precision
                 */
                fmt = (fmt << 1) | df;
                switch (subop) {
                        case 0: /* FCNVFF */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(MAJOR_0C_EXCP);
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvff(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvff(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 1: /* FCNVXF */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 2: /* FCNVFX */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 3: /* FCNVFXT */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 5: /* FCNVUF (PA2.0 only) */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 6: /* FCNVFU (PA2.0 only) */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 7: /* FCNVFUT (PA2.0 only) */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 4: /* undefined */
                                return(MAJOR_0C_EXCP);
                } /* end of switch subop */
                BUG();
        case 2: /* class 2 */
                fpu_type_flags=fpregs[FPU_TYPE_FLAG_POS];
                r2 = extru(ir, fpr2pos, 5) * sizeof(double)/sizeof(u_int);
                if (r2 == 0)
                        r2 = fpzeroreg;
                if  (fpu_type_flags & PA2_0_FPU_FLAG) {
                        /* FTEST if nullify bit set, otherwise FCMP */
                        if (extru(ir, fpnulpos, 1)) {  /* FTEST */
                                switch (fmt) {
                                    case 0:
                                        /*
                                         * arg0 is not used
                                         * second param is the t field used for
                                         * ftest,acc and ftest,rej
                                         * third param is the subop (y-field)
                                         */
                                        BUG();
                                        /* Unsupported
                                         * return(ftest(0L,extru(ir,fptpos,5),
                                         *       &fpregs[0],subop));
                                         */
                                    case 1:
                                    case 2:
                                    case 3:
                                        return(MAJOR_0C_EXCP);
                                }
                        } else {  /* FCMP */
                                switch (fmt) {
                                    case 0:
                                        retval = sgl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                    case 1:
                                        retval = dbl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                        }
                }  /* end of if for PA2.0 */
                else {  /* PA1.0 & PA1.1 */
                    switch (subop) {
                        case 2:
                        case 3:
                        case 4:
                        case 5:
                        case 6:
                        case 7:
                                return(MAJOR_0C_EXCP);
                        case 0: /* FCMP */
                                switch (fmt) {
                                    case 0:
                                        retval = sgl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                    case 1:
                                        retval = dbl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 1: /* FTEST */
                                switch (fmt) {
                                    case 0:
                                        /*
                                         * arg0 is not used
                                         * second param is the t field used for
                                         * ftest,acc and ftest,rej
                                         * third param is the subop (y-field)
                                         */
                                        BUG();
                                        /* unsupported
                                         * return(ftest(0L,extru(ir,fptpos,5),
                                         *     &fpregs[0],subop));
                                         */
                                    case 1:
                                    case 2:
                                    case 3:
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                    } /* end of switch subop */
                } /* end of else for PA1.0 & PA1.1 */
                BUG();
        case 3: /* class 3 */
                r2 = extru(ir,fpr2pos,5) * sizeof(double)/sizeof(u_int);
                if (r2 == 0)
                        r2 = fpzeroreg;
                switch (subop) {
                        case 5:
                        case 6:
                        case 7:
                                return(MAJOR_0C_EXCP);
                        
                        case 0: /* FADD */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fadd(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fadd(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 1: /* FSUB */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fsub(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fsub(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 2: /* FMPY */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fmpy(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fmpy(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 3: /* FDIV */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fdiv(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fdiv(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                        case 4: /* FREM */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_frem(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_frem(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 2: /* illegal */
                                    case 3: /* quad not implemented */
                                        return(MAJOR_0C_EXCP);
                                }
                                BUG();
                } /* end of class 3 switch */
        } /* end of switch(class) */

        /* If we get here, something is really wrong! */
        return(MAJOR_0C_EXCP);
}

static u_int
decode_0e(ir,class,subop,fpregs)
u_int ir,class,subop;
u_int fpregs[];
{
        u_int r1,r2,t;          /* operand register offsets */
        u_int fmt;              /* also sf for class 1 conversions */
        u_int df;               /* dest format for class 1 conversions */
        u_int *status;
        u_int retval, local_status;
        u_int fpu_type_flags;

        status = &fpregs[0];
        local_status = fpregs[0];
        r1 = ((extru(ir,fpr1pos,5)<<1)|(extru(ir,fpxr1pos,1)));
        if (r1 == 0)
                r1 = fpzeroreg;
        t = ((extru(ir,fptpos,5)<<1)|(extru(ir,fpxtpos,1)));
        if (t == 0 && class != 2)
                return(MAJOR_0E_EXCP);
        if (class < 2)          /* class 0 or 1 has 2 bit fmt */
                fmt = extru(ir,fpfmtpos,2);
        else                    /* class 2 and 3 have 1 bit fmt */
                fmt = extru(ir,fp0efmtpos,1);
        /*
         * An undefined combination, double precision accessing the
         * right half of a FPR, can get us into trouble.  
         * Let's just force proper alignment on it.
         */
        if (fmt == DBL) {
                r1 &= ~1;
                if (class != 1)
                        t &= ~1;
        }

        switch (class) {
            case 0:
                switch (subop) {
                        case 0: /* unimplemented */
                        case 1:
                                return(MAJOR_0E_EXCP);
                        case 2: /* FCPY */
                                switch (fmt) {
                                    case 2:
                                    case 3:
                                        return(MAJOR_0E_EXCP);
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        fpregs[t] = fpregs[r1];
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 3: /* FABS */
                                switch (fmt) {
                                    case 2:
                                    case 3:
                                        return(MAJOR_0E_EXCP);
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        fpregs[t] = fpregs[r1] & 0x7fffffff;
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 6: /* FNEG */
                                switch (fmt) {
                                    case 2:
                                    case 3:
                                        return(MAJOR_0E_EXCP);
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        fpregs[t] = fpregs[r1] ^ 0x80000000;
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 7: /* FNEGABS */
                                switch (fmt) {
                                    case 2:
                                    case 3:
                                        return(MAJOR_0E_EXCP);
                                    case 1: /* double */
                                        fpregs[t+1] = fpregs[r1+1];
                                        fallthrough;
                                    case 0: /* single */
                                        fpregs[t] = fpregs[r1] | 0x80000000;
                                        return(NOEXCEPTION);
                                }
                                BUG();
                        case 4: /* FSQRT */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fsqrt(&fpregs[r1],0,
                                                &fpregs[t], status));
                                    case 1:
                                        return(dbl_fsqrt(&fpregs[r1],0,
                                                &fpregs[t], status));
                                    case 2:
                                    case 3:
                                        return(MAJOR_0E_EXCP);
                                }
                                BUG();
                        case 5: /* FRMD */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_frnd(&fpregs[r1],0,
                                                &fpregs[t], status));
                                    case 1:
                                        return(dbl_frnd(&fpregs[r1],0,
                                                &fpregs[t], status));
                                    case 2:
                                    case 3:
                                        return(MAJOR_0E_EXCP);
                                }
                } /* end of switch (subop */
                BUG();
        case 1: /* class 1 */
                df = extru(ir,fpdfpos,2); /* get dest format */
                /*
                 * Fix Crashme problem (writing to 31R in double precision)
                 * here too.
                 */
                if (df == DBL) {
                        t &= ~1;
                }
                if ((df & 2) || (fmt & 2))
                        return(MAJOR_0E_EXCP);
                
                fmt = (fmt << 1) | df;
                switch (subop) {
                        case 0: /* FCNVFF */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(MAJOR_0E_EXCP);
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvff(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvff(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(MAJOR_0E_EXCP);
                                }
                                BUG();
                        case 1: /* FCNVXF */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvxf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 2: /* FCNVFX */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfx(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 3: /* FCNVFXT */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfxt(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 5: /* FCNVUF (PA2.0 only) */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvuf(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 6: /* FCNVFU (PA2.0 only) */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfu(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 7: /* FCNVFUT (PA2.0 only) */
                                switch(fmt) {
                                    case 0: /* sgl/sgl */
                                        return(sgl_to_sgl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 1: /* sgl/dbl */
                                        return(sgl_to_dbl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 2: /* dbl/sgl */
                                        return(dbl_to_sgl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                    case 3: /* dbl/dbl */
                                        return(dbl_to_dbl_fcnvfut(&fpregs[r1],0,
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 4: /* undefined */
                                return(MAJOR_0C_EXCP);
                } /* end of switch subop */
                BUG();
        case 2: /* class 2 */
                /*
                 * Be careful out there.
                 * Crashme can generate cases where FR31R is specified
                 * as the source or target of a double precision operation.
                 * Since we just pass the address of the floating-point
                 * register to the emulation routines, this can cause
                 * corruption of fpzeroreg.
                 */
                if (fmt == DBL)
                        r2 = (extru(ir,fpr2pos,5)<<1);
                else
                        r2 = ((extru(ir,fpr2pos,5)<<1)|(extru(ir,fpxr2pos,1)));
                fpu_type_flags=fpregs[FPU_TYPE_FLAG_POS];
                if (r2 == 0)
                        r2 = fpzeroreg;
                if  (fpu_type_flags & PA2_0_FPU_FLAG) {
                        /* FTEST if nullify bit set, otherwise FCMP */
                        if (extru(ir, fpnulpos, 1)) {  /* FTEST */
                                /* not legal */
                                return(MAJOR_0E_EXCP);
                        } else {  /* FCMP */
                        switch (fmt) {
                                    /*
                                     * fmt is only 1 bit long
                                     */
                                    case 0:
                                        retval = sgl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                    case 1:

                                        retval = dbl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                }
                        }
                }  /* end of if for PA2.0 */
                else {  /* PA1.0 & PA1.1 */
                    switch (subop) {
                        case 1:
                        case 2:
                        case 3:
                        case 4:
                        case 5:
                        case 6:
                        case 7:
                                return(MAJOR_0E_EXCP);
                        case 0: /* FCMP */
                                switch (fmt) {
                                    /*
                                     * fmt is only 1 bit long
                                     */
                                    case 0:
                                        retval = sgl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                    case 1:
                                        retval = dbl_fcmp(&fpregs[r1],
                                                &fpregs[r2],extru(ir,fptpos,5),
                                                &local_status);
                                        update_status_cbit(status,local_status,
                                                fpu_type_flags, subop);
                                        return(retval);
                                }
                    } /* end of switch subop */
                } /* end of else for PA1.0 & PA1.1 */
                BUG();
        case 3: /* class 3 */
                /*
                 * Be careful out there.
                 * Crashme can generate cases where FR31R is specified
                 * as the source or target of a double precision operation.
                 * Since we just pass the address of the floating-point
                 * register to the emulation routines, this can cause
                 * corruption of fpzeroreg.
                 */
                if (fmt == DBL)
                        r2 = (extru(ir,fpr2pos,5)<<1);
                else
                        r2 = ((extru(ir,fpr2pos,5)<<1)|(extru(ir,fpxr2pos,1)));
                if (r2 == 0)
                        r2 = fpzeroreg;
                switch (subop) {
                        case 5:
                        case 6:
                        case 7:
                                return(MAJOR_0E_EXCP);
                        
                        /*
                         * Note that fmt is only 1 bit for class 3 */
                        case 0: /* FADD */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fadd(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fadd(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 1: /* FSUB */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fsub(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fsub(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 2: /* FMPY or XMPYU */
                                /*
                                 * check for integer multiply (x bit set)
                                 */
                                if (extru(ir,fpxpos,1)) {
                                    /*
                                     * emulate XMPYU
                                     */
                                    switch (fmt) {
                                        case 0:
                                            /*
                                             * bad instruction if t specifies
                                             * the right half of a register
                                             */
                                            if (t & 1)
                                                return(MAJOR_0E_EXCP);
                                            BUG();
                                            /* unsupported
                                             * impyu(&fpregs[r1],&fpregs[r2],
                                                 * &fpregs[t]);
                                             */
                                            return(NOEXCEPTION);
                                        case 1:
                                                return(MAJOR_0E_EXCP);
                                    }
                                }
                                else { /* FMPY */
                                    switch (fmt) {
                                        case 0:
                                            return(sgl_fmpy(&fpregs[r1],
                                               &fpregs[r2],&fpregs[t],status));
                                        case 1:
                                            return(dbl_fmpy(&fpregs[r1],
                                               &fpregs[r2],&fpregs[t],status));
                                    }
                                }
                                BUG();
                        case 3: /* FDIV */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_fdiv(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_fdiv(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                }
                                BUG();
                        case 4: /* FREM */
                                switch (fmt) {
                                    case 0:
                                        return(sgl_frem(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                    case 1:
                                        return(dbl_frem(&fpregs[r1],&fpregs[r2],
                                                &fpregs[t],status));
                                }
                } /* end of class 3 switch */
        } /* end of switch(class) */

        /* If we get here, something is really wrong! */
        return(MAJOR_0E_EXCP);
}


/*
 * routine to decode the 06 (FMPYADD and FMPYCFXT) instruction
 */
static u_int
decode_06(ir,fpregs)
u_int ir;
u_int fpregs[];
{
        u_int rm1, rm2, tm, ra, ta; /* operands */
        u_int fmt;
        u_int error = 0;
        u_int status;
        u_int fpu_type_flags;
        union {
                double dbl;
                float flt;
                struct { u_int i1; u_int i2; } ints;
        } mtmp, atmp;


        status = fpregs[0];             /* use a local copy of status reg */
        fpu_type_flags=fpregs[FPU_TYPE_FLAG_POS];  /* get fpu type flags */
        fmt = extru(ir, fpmultifmt, 1); /* get sgl/dbl flag */
        if (fmt == 0) { /* DBL */
                rm1 = extru(ir, fprm1pos, 5) * sizeof(double)/sizeof(u_int);
                if (rm1 == 0)
                        rm1 = fpzeroreg;
                rm2 = extru(ir, fprm2pos, 5) * sizeof(double)/sizeof(u_int);
                if (rm2 == 0)
                        rm2 = fpzeroreg;
                tm = extru(ir, fptmpos, 5) * sizeof(double)/sizeof(u_int);
                if (tm == 0)
                        return(MAJOR_06_EXCP);
                ra = extru(ir, fprapos, 5) * sizeof(double)/sizeof(u_int);
                ta = extru(ir, fptapos, 5) * sizeof(double)/sizeof(u_int);
                if (ta == 0)
                        return(MAJOR_06_EXCP);

                if  (fpu_type_flags & TIMEX_ROLEX_FPU_MASK)  {

                        if (ra == 0) {
                                /* special case FMPYCFXT, see sgl case below */
                                if (dbl_fmpy(&fpregs[rm1],&fpregs[rm2],
                                        &mtmp.ints.i1,&status))
                                        error = 1;
                                if (dbl_to_sgl_fcnvfxt(&fpregs[ta],
                                        &atmp.ints.i1,&atmp.ints.i1,&status))
                                        error = 1;
                                }
                        else {

                        if (dbl_fmpy(&fpregs[rm1],&fpregs[rm2],&mtmp.ints.i1,
                                        &status))
                                error = 1;
                        if (dbl_fadd(&fpregs[ta], &fpregs[ra], &atmp.ints.i1,
                                        &status))
                                error = 1;
                                }
                        }

                else

                        {
                        if (ra == 0)
                                ra = fpzeroreg;

                        if (dbl_fmpy(&fpregs[rm1],&fpregs[rm2],&mtmp.ints.i1,
                                        &status))
                                error = 1;
                        if (dbl_fadd(&fpregs[ta], &fpregs[ra], &atmp.ints.i1,
                                        &status))
                                error = 1;

                        }

                if (error)
                        return(MAJOR_06_EXCP);
                else {
                        /* copy results */
                        fpregs[tm] = mtmp.ints.i1;
                        fpregs[tm+1] = mtmp.ints.i2;
                        fpregs[ta] = atmp.ints.i1;
                        fpregs[ta+1] = atmp.ints.i2;
                        fpregs[0] = status;
                        return(NOEXCEPTION);
                }
        }
        else { /* SGL */
                /*
                 * calculate offsets for single precision numbers
                 * See table 6-14 in PA-89 architecture for mapping
                 */
                rm1 = (extru(ir,fprm1pos,4) | 0x10 ) << 1;      /* get offset */
                rm1 |= extru(ir,fprm1pos-4,1);  /* add right word offset */

                rm2 = (extru(ir,fprm2pos,4) | 0x10 ) << 1;      /* get offset */
                rm2 |= extru(ir,fprm2pos-4,1);  /* add right word offset */

                tm = (extru(ir,fptmpos,4) | 0x10 ) << 1;        /* get offset */
                tm |= extru(ir,fptmpos-4,1);    /* add right word offset */

                ra = (extru(ir,fprapos,4) | 0x10 ) << 1;        /* get offset */
                ra |= extru(ir,fprapos-4,1);    /* add right word offset */

                ta = (extru(ir,fptapos,4) | 0x10 ) << 1;        /* get offset */
                ta |= extru(ir,fptapos-4,1);    /* add right word offset */
                
                if (ra == 0x20 &&(fpu_type_flags & TIMEX_ROLEX_FPU_MASK)) {
                        /* special case FMPYCFXT (really 0)
                          * This instruction is only present on the Timex and
                          * Rolex fpu's in so if it is the special case and
                          * one of these fpu's we run the FMPYCFXT instruction
                          */
                        if (sgl_fmpy(&fpregs[rm1],&fpregs[rm2],&mtmp.ints.i1,
                                        &status))
                                error = 1;
                        if (sgl_to_sgl_fcnvfxt(&fpregs[ta],&atmp.ints.i1,
                                &atmp.ints.i1,&status))
                                error = 1;
                }
                else {
                        if (sgl_fmpy(&fpregs[rm1],&fpregs[rm2],&mtmp.ints.i1,
                                        &status))
                                error = 1;
                        if (sgl_fadd(&fpregs[ta], &fpregs[ra], &atmp.ints.i1,
                                        &status))
                                error = 1;
                }
                if (error)
                        return(MAJOR_06_EXCP);
                else {
                        /* copy results */
                        fpregs[tm] = mtmp.ints.i1;
                        fpregs[ta] = atmp.ints.i1;
                        fpregs[0] = status;
                        return(NOEXCEPTION);
                }
        }
}

/*
 * routine to decode the 26 (FMPYSUB) instruction
 */
static u_int
decode_26(ir,fpregs)
u_int ir;
u_int fpregs[];
{
        u_int rm1, rm2, tm, ra, ta; /* operands */
        u_int fmt;
        u_int error = 0;
        u_int status;
        union {
                double dbl;
                float flt;
                struct { u_int i1; u_int i2; } ints;
        } mtmp, atmp;


        status = fpregs[0];
        fmt = extru(ir, fpmultifmt, 1); /* get sgl/dbl flag */
        if (fmt == 0) { /* DBL */
                rm1 = extru(ir, fprm1pos, 5) * sizeof(double)/sizeof(u_int);
                if (rm1 == 0)
                        rm1 = fpzeroreg;
                rm2 = extru(ir, fprm2pos, 5) * sizeof(double)/sizeof(u_int);
                if (rm2 == 0)
                        rm2 = fpzeroreg;
                tm = extru(ir, fptmpos, 5) * sizeof(double)/sizeof(u_int);
                if (tm == 0)
                        return(MAJOR_26_EXCP);
                ra = extru(ir, fprapos, 5) * sizeof(double)/sizeof(u_int);
                if (ra == 0)
                        return(MAJOR_26_EXCP);
                ta = extru(ir, fptapos, 5) * sizeof(double)/sizeof(u_int);
                if (ta == 0)
                        return(MAJOR_26_EXCP);
                
                if (dbl_fmpy(&fpregs[rm1],&fpregs[rm2],&mtmp.ints.i1,&status))
                        error = 1;
                if (dbl_fsub(&fpregs[ta], &fpregs[ra], &atmp.ints.i1,&status))
                        error = 1;
                if (error)
                        return(MAJOR_26_EXCP);
                else {
                        /* copy results */
                        fpregs[tm] = mtmp.ints.i1;
                        fpregs[tm+1] = mtmp.ints.i2;
                        fpregs[ta] = atmp.ints.i1;
                        fpregs[ta+1] = atmp.ints.i2;
                        fpregs[0] = status;
                        return(NOEXCEPTION);
                }
        }
        else { /* SGL */
                /*
                 * calculate offsets for single precision numbers
                 * See table 6-14 in PA-89 architecture for mapping
                 */
                rm1 = (extru(ir,fprm1pos,4) | 0x10 ) << 1;      /* get offset */
                rm1 |= extru(ir,fprm1pos-4,1);  /* add right word offset */

                rm2 = (extru(ir,fprm2pos,4) | 0x10 ) << 1;      /* get offset */
                rm2 |= extru(ir,fprm2pos-4,1);  /* add right word offset */

                tm = (extru(ir,fptmpos,4) | 0x10 ) << 1;        /* get offset */
                tm |= extru(ir,fptmpos-4,1);    /* add right word offset */

                ra = (extru(ir,fprapos,4) | 0x10 ) << 1;        /* get offset */
                ra |= extru(ir,fprapos-4,1);    /* add right word offset */

                ta = (extru(ir,fptapos,4) | 0x10 ) << 1;        /* get offset */
                ta |= extru(ir,fptapos-4,1);    /* add right word offset */
                
                if (sgl_fmpy(&fpregs[rm1],&fpregs[rm2],&mtmp.ints.i1,&status))
                        error = 1;
                if (sgl_fsub(&fpregs[ta], &fpregs[ra], &atmp.ints.i1,&status))
                        error = 1;
                if (error)
                        return(MAJOR_26_EXCP);
                else {
                        /* copy results */
                        fpregs[tm] = mtmp.ints.i1;
                        fpregs[ta] = atmp.ints.i1;
                        fpregs[0] = status;
                        return(NOEXCEPTION);
                }
        }

}

/*
 * routine to decode the 2E (FMPYFADD,FMPYNFADD) instructions
 */
static u_int
decode_2e(ir,fpregs)
u_int ir;
u_int fpregs[];
{
        u_int rm1, rm2, ra, t; /* operands */
        u_int fmt;

        fmt = extru(ir,fpfmtpos,1);     /* get fmt completer */
        if (fmt == DBL) { /* DBL */
                rm1 = extru(ir,fprm1pos,5) * sizeof(double)/sizeof(u_int);
                if (rm1 == 0)
                        rm1 = fpzeroreg;
                rm2 = extru(ir,fprm2pos,5) * sizeof(double)/sizeof(u_int);
                if (rm2 == 0)
                        rm2 = fpzeroreg;
                ra = ((extru(ir,fpraupos,3)<<2)|(extru(ir,fpralpos,3)>>1)) *
                     sizeof(double)/sizeof(u_int);
                if (ra == 0)
                        ra = fpzeroreg;
                t = extru(ir,fptpos,5) * sizeof(double)/sizeof(u_int);
                if (t == 0)
                        return(MAJOR_2E_EXCP);

                if (extru(ir,fpfusedsubop,1)) { /* fmpyfadd or fmpynfadd? */
                        return(dbl_fmpynfadd(&fpregs[rm1], &fpregs[rm2],
                                        &fpregs[ra], &fpregs[0], &fpregs[t]));
                } else {
                        return(dbl_fmpyfadd(&fpregs[rm1], &fpregs[rm2],
                                        &fpregs[ra], &fpregs[0], &fpregs[t]));
                }
        } /* end DBL */
        else { /* SGL */
                rm1 = (extru(ir,fprm1pos,5)<<1)|(extru(ir,fpxrm1pos,1));
                if (rm1 == 0)
                        rm1 = fpzeroreg;
                rm2 = (extru(ir,fprm2pos,5)<<1)|(extru(ir,fpxrm2pos,1));
                if (rm2 == 0)
                        rm2 = fpzeroreg;
                ra = (extru(ir,fpraupos,3)<<3)|extru(ir,fpralpos,3);
                if (ra == 0)
                        ra = fpzeroreg;
                t = ((extru(ir,fptpos,5)<<1)|(extru(ir,fpxtpos,1)));
                if (t == 0)
                        return(MAJOR_2E_EXCP);

                if (extru(ir,fpfusedsubop,1)) { /* fmpyfadd or fmpynfadd? */
                        return(sgl_fmpynfadd(&fpregs[rm1], &fpregs[rm2],
                                        &fpregs[ra], &fpregs[0], &fpregs[t]));
                } else {
                        return(sgl_fmpyfadd(&fpregs[rm1], &fpregs[rm2],
                                        &fpregs[ra], &fpregs[0], &fpregs[t]));
                }
        } /* end SGL */
}

/*
 * update_status_cbit
 *
 *      This routine returns the correct FP status register value in
 *      *status, based on the C-bit & V-bit returned by the FCMP
 *      emulation routine in new_status.  The architecture type
 *      (PA83, PA89 or PA2.0) is available in fpu_type.  The y_field
 *      and the architecture type are used to determine what flavor
 *      of FCMP is being emulated.
 */
static void
update_status_cbit(status, new_status, fpu_type, y_field)
u_int *status, new_status;
u_int fpu_type;
u_int y_field;
{
        /*
         * For PA89 FPU's which implement the Compare Queue and
         * for PA2.0 FPU's, update the Compare Queue if the y-field = 0,
         * otherwise update the specified bit in the Compare Array.
         * Note that the y-field will always be 0 for non-PA2.0 FPU's.
         */
        if ((fpu_type & TIMEX_EXTEN_FLAG) || 
            (fpu_type & ROLEX_EXTEN_FLAG) ||
            (fpu_type & PA2_0_FPU_FLAG)) {
                if (y_field == 0) {
                        *status = ((*status & 0x04000000) >> 5) | /* old Cbit */
                                  ((*status & 0x003ff000) >> 1) | /* old CQ   */
                                  (new_status & 0xffc007ff); /* all other bits*/
                } else {
                        *status = (*status & 0x04000000) |     /* old Cbit */
                                  ((new_status & 0x04000000) >> (y_field+4)) |
                                  (new_status & ~0x04000000 &  /* other bits */
                                   ~(0x04000000 >> (y_field+4)));
                }
        }
        /* if PA83, just update the C-bit */
        else {
                *status = new_status;
        }
}