Intel 64 and IA-32 Architectures Software Developers Manual Volume 1, Basic Architecture

Vol. 1 E-31
GUIDELINES FOR WRITING SIMD FLOATING-POINT EXCEPTION HANDLERS
// read status word to see if result is inexact
__asm {
fstsw WORD PTR sw;
}
if (sw & UNDERFLOW_MASK) exc_env->status_flag_underflow = 1;
if (sw & OVERFLOW_MASK) exc_env->status_flag_overflow = 1;
if (sw & PRECISION_MASK) exc_env->status_flag_inexact = 1;
// if ftz = 1, and result is tiny (underflow traps must be disabled),
// result = 0.0
if (exc_env->ftz && result_tiny) {
if (res > 0.0)
res = ZEROF;
else if (res < 0.0)
res = NZEROF;
// else leave res unchanged
exc_env->status_flag_inexact = 1;
exc_env->status_flag_underflow = 1;
}
exc_env->result_fval = res;
if (sw & ZERODIVIDE_MASK) exc_env->status_flag_divide_by_zero = 1;
if (sw & DENORMAL_MASK) exc_env->status_flag_denormal= 1;
if (sw & INVALID_MASK) exc_env->status_flag_invalid_operation = 1;
return (DO_NOT_RAISE_EXCEPTION);
break;
case CMPPS:
case CMPSS:
...
break;
case COMISS:
case UCOMISS:
...
break;
case CVTPI2PS:
case CVTSI2SS:
...
break;
case CVTPS2PI: