2.11BSD#431 - /usr/ingres/source/equel/runtime/IIconvert.c

   1: # include   "../../symbol.h"
   2: 
   3: /*
   4: **
   5: **	IIconvert -- Equel run-tme routine to convert
   6: **		numeric values of one type and length, to a
   7: **		(not necessarily) different type and length.
   8: **
   9: **		The source numeric can be i1, i2, i4, f4, or f8.
  10: **
  11: **		The source number will be converted to the
  12: **		type and length specified in the destination.
  13: **		It also must be one of i1, i2, i4, f4, or f8.
  14: **
  15: **		IIconvert returns 0 if no overflow occured,
  16: **		otherwise it returns -1
  17: **
  18: */
  19: 
  20: 
  21: IIconvert(inp, outp, sf, slen, df, dlen)
  22: char        *inp;       /* input area */
  23: char        *outp;      /* output area */
  24: int     sf;     /* format of the source number */
  25: int     slen;       /* length of the source number */
  26: int     df;     /* format of the dest */
  27: int     dlen;       /* length of the dest */
  28: {
  29:     char        number[8];  /* dummy buffer */
  30:     register char   *num;
  31:     register int    sl;     /* refers to length
  32: 					 * of "number"
  33: 					 */
  34:     register int    dl;
  35: 
  36: #	define    i1deref(x)  (*((char *)(x)))
  37: #	define    i2deref(x)  (*((int *)(x)))
  38: #	define    i4deref(x)  (*((long *)(x)))
  39: #	define    f4deref(x)  (*((float *)(x)))
  40: #	define    f8deref(x)  (*((double *)(x)))
  41: 
  42:     dl = dlen;
  43:     sl = slen;
  44:     num = number;
  45:     IIbmove(inp, num,  sl); /* copy number into buffer */
  46: 
  47:     if (sf != df)
  48:     {
  49:         /* if the source and destination formats are
  50: 		 * different then the source must be converted
  51: 		 * to i4 if the dest is int, otherwise to f8
  52: 		 */
  53: 
  54:         if (df == FLOAT)    /* {sf == INT} INT->f8 */
  55:         {
  56:             switch (sl)
  57:             {
  58: 
  59:               case 1:
  60:                 f8deref(num) = i1deref(num);    /* i1 to f8 */
  61:                 break;
  62: 
  63:               case 2:
  64:                 f8deref(num) = i2deref(num);    /* i2 to f8 */
  65:                 break;
  66: 
  67:               case 4:
  68:                 f8deref(num) = i4deref(num);    /* i4 to f8 */
  69:             }
  70:             sl = 8;         /* df == INT && sf == FLOAT
  71: 						 * && sl == 8
  72: 						 */
  73:         }
  74:         else
  75:         {
  76:             /* {df == INT && sf == FLOAT} FLOAT->i4 */
  77: 
  78:             /* check if float >  2**31 */
  79:             if (sl == 8)
  80:                 f4deref(num) = f8deref(num);    /* f8 to f4 */
  81: 
  82:             if (f4deref(num) > 2147483647.0 || f4deref(num) < -2147483648.0)
  83:                 return (-1);
  84:             i4deref(num) = f4deref(num);
  85:             sl = 4;
  86:         }
  87:     }
  88: 
  89:     /* number is now the same type as destination */
  90:     /* convert lengths to match */
  91: 
  92:     if (sl != dl)
  93:     {
  94:         /* lengths don't match. convert. */
  95:         if (df == FLOAT)
  96:         {
  97:             if (dl == 8)
  98:                 f8deref(num) = f4deref(num);    /* f4 to f8 */
  99:             else
 100:                 f4deref(num) = f8deref(num);    /* f8 to f4 with rounding */
 101:         }
 102:         else
 103:         {
 104:             switch (dl)
 105:             {
 106: 
 107:               case 1:
 108:                 if (sl == 2)        /* i2 to i1 */
 109:                 {
 110:                     if (i2deref(num) > 127 || i2deref(num) < -128)
 111:                         return (-1);
 112:                     i1deref(num) = i2deref(num);
 113:                 }
 114:                 else            /* i4 to i1 */
 115:                 {
 116:                     if (i4deref(num) > 127 || i4deref(num) < -128)
 117:                         return (-1);
 118:                     i1deref(num) = i4deref(num);
 119:                 }
 120:                 break;
 121: 
 122:               case 2:
 123:                 if (sl == 1)        /* i1 to i2 */
 124:                 {
 125:                     i2deref(num) = i1deref(num);
 126:                 }
 127:                 else            /* i4 to i2 */
 128:                 {
 129:                     if (i4deref(num) > 32767 || i4deref(num) < -32768)
 130:                         return (-1);
 131:                     i2deref(num) = i4deref(num);
 132:                 }
 133:                 break;
 134: 
 135:               case 4:
 136:                 if (sl == 1)        /* i1 to i4 */
 137:                     i4deref(num) = i1deref(num);
 138:                 else            /* i2 to i4 */
 139:                     i4deref(num) = i2deref(num);
 140:             }
 141:         }
 142:     }
 143: 
 144:     /* conversion is complete
 145: 	 * copy the result into outp
 146: 	 */
 147: 
 148:     IIbmove(num, outp, dl);
 149:     return (0);
 150: }

Defined functions

Defined macros