diff options
Diffstat (limited to 'kernel/arch/x86/math-emu/reg_convert.c')
| -rw-r--r-- | kernel/arch/x86/math-emu/reg_convert.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/kernel/arch/x86/math-emu/reg_convert.c b/kernel/arch/x86/math-emu/reg_convert.c new file mode 100644 index 000000000..108060779 --- /dev/null +++ b/kernel/arch/x86/math-emu/reg_convert.c @@ -0,0 +1,46 @@ +/*---------------------------------------------------------------------------+ + | reg_convert.c | + | | + | Convert register representation. | + | | + | Copyright (C) 1992,1993,1994,1996,1997 | + | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | + | E-mail billm@suburbia.net | + | | + | | + +---------------------------------------------------------------------------*/ + +#include "exception.h" +#include "fpu_emu.h" + +int FPU_to_exp16(FPU_REG const *a, FPU_REG *x) +{ + int sign = getsign(a); + + *(long long *)&(x->sigl) = *(const long long *)&(a->sigl); + + /* Set up the exponent as a 16 bit quantity. */ + setexponent16(x, exponent(a)); + + if (exponent16(x) == EXP_UNDER) { + /* The number is a de-normal or pseudodenormal. */ + /* We only deal with the significand and exponent. */ + + if (x->sigh & 0x80000000) { + /* Is a pseudodenormal. */ + /* This is non-80486 behaviour because the number + loses its 'denormal' identity. */ + addexponent(x, 1); + } else { + /* Is a denormal. */ + addexponent(x, 1); + FPU_normalize_nuo(x); + } + } + + if (!(x->sigh & 0x80000000)) { + EXCEPTION(EX_INTERNAL | 0x180); + } + + return sign; +} |