1 /*---------------------------------------------------------------------------+ 2 | reg_convert.c | 3 | | 4 | Convert register representation. | 5 | | 6 | Copyright (C) 1992,1993,1994,1996,1997 | 7 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | 8 | E-mail billm@suburbia.net | 9 | | 10 | | 11 +---------------------------------------------------------------------------*/ 12 13 #include "exception.h" 14 #include "fpu_emu.h" 15 16 int FPU_to_exp16(FPU_REG const *a, FPU_REG *x) 17 { 18 int sign = getsign(a); 19 20 *(long long *)&(x->sigl) = *(const long long *)&(a->sigl); 21 22 /* Set up the exponent as a 16 bit quantity. */ 23 setexponent16(x, exponent(a)); 24 25 if (exponent16(x) == EXP_UNDER) { 26 /* The number is a de-normal or pseudodenormal. */ 27 /* We only deal with the significand and exponent. */ 28 29 if (x->sigh & 0x80000000) { 30 /* Is a pseudodenormal. */ 31 /* This is non-80486 behaviour because the number 32 loses its 'denormal' identity. */ 33 addexponent(x, 1); 34 } else { 35 /* Is a denormal. */ 36 addexponent(x, 1); 37 FPU_normalize_nuo(x); 38 } 39 } 40 41 if (!(x->sigh & 0x80000000)) { 42 EXCEPTION(EX_INTERNAL | 0x180); 43 } 44 45 return sign; 46 } 47