sys/src/cmd/5e/vfp.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <thread.h>
   4 #include <bio.h>
   5 #include <mach.h>
   6 #include "dat.h"
   7 #include "fns.h"
   8
   9 void
  10 resetvfp(void)
  11 {
  12         int i;
  13
  14         P->FPSR = 0x00000000;
  15         for(i = 0; i < Nfpregs; i++)
  16                 P->F[i] = 0;
  17 }
  18
  19 void
  20 vfpregtransfer(u32int instr)
  21 {
  22         u32int *Rt;
  23         long double *Fn;
  24         Rt = P->R + ((instr>>12)&0xF);
  25         Fn = P->F + ((instr>>16)&0xF);
  26
  27         switch((instr>>20)&0xF){
  28         case 0:
  29                 *((int*)Fn) = *Rt; break;
  30         case 1:
  31                 *Rt = *((int*)Fn); break;
  32         case 14:
  33                 P->FPSR = *Rt; break;
  34         case 15:
  35                 if(Rt == (P->R + 15))
  36                         P->CPSR = P->FPSR;
  37                 else
  38                         *Rt = P->FPSR;
  39                 break;
  40         default:
  41                 sysfatal("unimplemented VFP instruction %8ux @ %8ux", instr, P->R[15] - 4);
  42         }
  43 }
  44
  45 void
  46 vfprmtransfer(u32int instr)
  47 {
  48         int n, d, off, sz;
  49         void* ea;
  50         Segment *seg;
  51
  52         n = (instr>>16) & 0xF;
  53         d = (instr>>12) & 0xF;
  54         off = (instr & 0xFF) << 2;
  55         sz = instr & (1<<8);
  56         if((instr & (1<<23)) == 0)
  57                 off = -off;
  58         ea = vaddr(P->R[n] + off, 8, &seg);
  59
  60         switch((instr>>20)&0x3){
  61         case 0:
  62                 if(sz)
  63                         *(double*)ea = P->F[d];
  64                 else
  65                         *(float*)ea = P->F[d];
  66                 break;
  67         case 1:
  68                 if(sz)
  69                         P->F[d] = *(double*)ea;
  70                 else
  71                         P->F[d] = *(float*)ea;
  72                 break;
  73         default:
  74                 sysfatal("unimplemented VFP instruction %8ux @ %8ux", instr, P->R[15] - 4);
  75         }
  76         segunlock(seg);
  77 }
  78
  79 void
  80 vfparithop(int opc, u32int instr)
  81 {
  82         int o;
  83         long double *Fd, *Fn, *Fm;
  84         Fd = P->F + ((instr>>12)&0xF);
  85         Fn = P->F + ((instr>>16)&0xF);
  86         Fm = P->F + (instr&0xF);
  87         o = ((opc&0x3)<<1) | (opc&0x8) | ((instr>>6)&0x1);
  88
  89         switch(o){
  90         case 4:
  91                 *Fd = *Fn * *Fm; break;
  92         case 6:
  93                 *Fd = *Fn + *Fm; break;
  94         case 7:
  95                 *Fd = *Fn - *Fm; break;
  96         case 8:
  97                 *Fd = *Fn / *Fm; break;
  98         default:
  99                 sysfatal("unimplemented VFP instruction %8ux @ %8ux", instr, P->R[15] - 4);
 100         }
 101 }
 102
 103 void
 104 vfpotherop(u32int instr)
 105 {
 106         int o2, o3;
 107         long double *Fd, *Fm, F0;
 108         Fd = P->F + ((instr>>12)&0xF);
 109         Fm = P->F + (instr&0xF);
 110         F0 = 0.0;
 111         o2 = (instr>>16) & 0xF;
 112         o3 = (instr>>6) & 0x3;
 113
 114         if((o3&1) == 0)
 115                 sysfatal("unimplemented VFP instruction %8ux @ %8ux", instr, P->R[15] - 4);
 116         switch(o2){
 117         case 0x5:
 118                 Fm = &F0;
 119         case 0x4:
 120                 if(*Fd < *Fm)
 121                         P->FPSR = (P->FPSR & ~FLAGS) | flN;
 122                 else if(*Fd >= *Fm) {
 123                         P->FPSR = (P->FPSR & ~FLAGS) | flC;
 124                         if(*Fd == *Fm)
 125                                 P->FPSR |= flZ;
 126                 } else
 127                         P->FPSR = (P->FPSR & ~FLAGS) | flV | flC;
 128                 break;
 129         case 0x8:
 130                 *Fd = *((int*)Fm); break;
 131         case 0xD:
 132                 *((int*)Fd) = (int)*Fm; break;
 133         default:
 134                 switch((o2<<1)|(o3>>1)){
 135                 case 0:
 136                 case 15:
 137                         *Fd = *Fm; break;
 138                 case 1:
 139                         *Fd = fabs(*Fm); break;
 140                 case 2:
 141                         *Fd = -*Fm; break;
 142                 case 3:
 143                         *Fd = sqrt(*Fm); break;
 144                 default:
 145                         sysfatal("unimplemented VFP instruction %8ux @ %8ux", instr, P->R[15] - 4);
 146                 }
 147         }
 148 }
 149
 150 void
 151 vfpoperation(u32int instr)
 152 {
 153         int o1;
 154         o1 = (instr>>20) & 0xF;
 155         if(o1 == 0xB)
 156                 vfpotherop(instr);
 157         else
 158                 vfparithop(o1, instr);
 159 }
 160