windows-nt/Source/XPSP1/NT/drivers/wdm/vbi/nabtsfec/dsp/r0float.c

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2020-09-26 03:20:57 -05:00
#ifdef _X86_
unsigned char _fltused;
long __cdecl
float2long(float arg)
{
long rval;
__asm {
fld arg ; Put <arg> into FPU
fistp rval ; Write out the long version
}
return rval;
}
unsigned short
__cdecl
floatSetup(void)
{
unsigned short oldCWord;
unsigned short newCWord;
__asm {
wait ; Let any pending FPU operations finish
fnstcw word ptr oldCWord ; w/o blocking, store FPU Control word
wait ; Wait for the store to complete
mov ax,word ptr oldCWord ; Load the CW into AX
or ah,0Ch ; Ensure the rounding bits are correct
mov word ptr newCWord,ax ; Save the modified CW from AX
fldcw word ptr newCWord ; Reset the control word with new value
}
return oldCWord;
}
void __cdecl
floatRestore(unsigned short ctlWord)
{
__asm {
wait ; Let any pending FPU operations finish
fldcw word ptr ctlWord ; Restore the CW from the original
}
}
#endif //_X86_