redo include files for kernel reorg

[unix-history] / usr / src / sys / tahoe / math / fpe.c

/*      fpe.c   1.4     90/12/04        */

#include "../include/psl.h"
#include "../include/reg.h"
#include "../include/pte.h"
#include "../include/mtpr.h"
#include "../math/Kfp.h"

#include "sys/param.h"
#include "sys/systm.h"
#include "sys/user.h"
#include "sys/proc.h"
#include "sys/seg.h"
#include "sys/acct.h"
#include "sys/kernel.h"

/*
* Floating point emulation support.
*/
extern  float Kcvtlf(), Kaddf(), Ksubf(), Kmulf(), Kdivf();
extern  double Kcvtld(), Kaddd(), Ksubd(), Kmuld(), Kdivd();
extern  float Ksinf(), Kcosf(), Katanf(), Klogf(), Ksqrtf(), Kexpf();

#define OP(dop)         ((dop) &~ 01)   /* precision-less version of opcode */
#define isdouble(op)    ((op) & 01)     /* is opcode double or float */

struct  fpetab {
       int     fpe_op;         /* base opcode emulating */
       float   (*fpe_ffunc)(); /* float version of op */
       double  (*fpe_dfunc)(); /* double version of op */
} fpetab[] = {
       { OP(CVLD),     Kcvtlf, Kcvtld },
       { OP(ADDD),     Kaddf,  Kaddd },
       { OP(SUBD),     Ksubf,  Ksubd },
       { OP(MULD),     Kmulf,  Kmuld },
       { OP(DIVD),     Kdivf,  Kdivd },
       { SINF,         Ksinf,  0 },
       { COSF,         Kcosf,  0 },
       { ATANF,        Katanf, 0 },
       { LOGF,         Klogf,  0 },
       { SQRTF,        Ksqrtf, 0 },
       { EXPF,         Kexpf,  0 },
};
#define NFPETAB (sizeof (fpetab) / sizeof (fpetab[0]))

/*
* Emulate the FP opcode. Update psl as necessary.
* If OK, set opcode to 0, else to the FP exception #.
* Not all parameter longwords are relevant, depends on opcode.
*
* The entry mask is set by locore.s so ALL registers are saved.
* This enables FP opcodes to change user registers on return.
*/
/* WARNING!!!! THIS CODE MUST NOT PRODUCE ANY FLOATING POINT EXCEPTIONS */
/*ARGSUSED*/
fpemulate(hfsreg, acc_most, acc_least, dbl, op_most, op_least, opcode, pc, psl)
{
       int r0, r1;                     /* must reserve space */
       register int *locr0 = ((int *)&psl)-PS;
       register struct fpetab *fp;
       int hfs = 0;                    /* returned data about exceptions */
       int type;                       /* opcode type, FLOAT or DOUBLE */
       union { float ff; int fi; } f_res;
       union { double dd; int di[2]; } d_res;
       int error = 0;

#ifdef lint
       r0 = 0; r0 = r0; r1 = 0; r1 = r1;
#endif
       type = isdouble(opcode) ? DOUBLE : FLOAT;
       for (fp = fpetab; fp < &fpetab[NFPETAB]; fp++)
               if ((opcode & 0xfe) == fp->fpe_op)
                       break;
       if (type == DOUBLE) {
               if (fp->fpe_dfunc == 0)
                       fp = &fpetab[NFPETAB];
               else
                       locr0[PS] &= ~PSL_DBL;
       }
       if (fp >= &fpetab[NFPETAB]) {
               opcode = DIV0_EXC;      /* generate SIGILL - XXX */
               return (0);
       }
       switch (type) {

       case DOUBLE:
               d_res.dd = (*fp->fpe_dfunc)(acc_most, acc_least, op_most,
                   op_least, &hfs);
               if (d_res.di[0] == 0 && d_res.di[1] == 0)
                       locr0[PS] |= PSL_Z;
               if (d_res.di[0] < 0)
                       locr0[PS] |= PSL_N;
               break;

       case FLOAT:
               f_res.ff = (*fp->fpe_ffunc)(acc_most, acc_least, op_most,
                   op_least, &hfs);
               if (f_res.fi == 0)
                       locr0[PS] |= PSL_Z;
               if (f_res.fi ==  0)
                       locr0[PS] |= PSL_N;
               break;
       }
       if (hfs & HFS_OVF) {
               locr0[PS] |= PSL_V;     /* turn on overflow bit */
#ifdef notdef
               if (locr0[PS] & PSL_IV)   {  /* overflow enabled? */
#endif
                       opcode = OVF_EXC;
                       return ((hfs & HFS_DOM) ? EDOM : ERANGE);
#ifdef notdef
               }
#endif
       } else if (hfs & HFS_UNDF) {
               if (locr0[PS] &  PSL_FU) {  /* underflow enabled? */
                       opcode = UNDF_EXC;
                       return ((hfs & HFS_DOM) ? EDOM : ERANGE);
               } 
       } else if (hfs & HFS_DIVZ) {
               opcode = DIV0_EXC;
               return (0);
       } else if (hfs & HFS_DOM)
               error = EDOM;
       else if (hfs & HFS_RANGE)
               error = ERANGE;
       switch (type) {

       case DOUBLE:
               if (hfs & (HFS_OVF|HFS_UNDF)) {
                       d_res.dd = 0.0;
                       locr0[PS] |= PSL_Z;
               }
               mvtodacc(d_res.di[0], d_res.di[1], &acc_most);
               break;

       case FLOAT:
               if (hfs & (HFS_OVF|HFS_UNDF)) {
                       f_res.ff = 0.0;
                       locr0[PS] |= PSL_Z;
               }
               mvtofacc(f_res.ff, &acc_most);
               break;
       }
       opcode = 0;
       return (error);
}