20060303a

1 files changed, 82 insertions, 0 deletions

diff --git a/libmath/FPcontrol-Nt.c b/libmath/FPcontrol-Nt.c
new file mode 100644
index 00000000..6a3fb22d
--- /dev/null
+++ b/libmath/FPcontrol-Nt.c
@@ -0,0 +1,82 @@
+#include "lib9.h"
+#include <float.h>
+#include "mathi.h"
+
+void
+FPinit(void)
+{
+	_controlfp(_EM_INEXACT,_MCW_EM);	// abort on underflow, etc.
+}
+
+ulong
+getFPstatus(void)
+{
+	ulong fsr = 0, fsr32 = _statusfp();
+	if(fsr32&_SW_INEXACT) fsr |= INEX;
+	if(fsr32&_SW_OVERFLOW) fsr |= OVFL;
+	if(fsr32&_SW_UNDERFLOW) fsr |= UNFL;
+	if(fsr32&_SW_ZERODIVIDE) fsr |= ZDIV;
+	if(fsr32&_SW_INVALID) fsr |= INVAL;
+	return fsr;
+}
+
+ulong
+FPstatus(ulong fsr, ulong mask)
+{
+	ulong old = getFPstatus();
+	fsr = (fsr&mask) | (old&~mask);
+	if(fsr!=old){
+		_clearfp();
+		if(fsr){
+			ulong fcr = _controlfp(0,0);
+			double x = 1., y = 1e200, z = 0.;
+			_controlfp(_MCW_EM,_MCW_EM);
+			if(fsr&INEX) z = x + y;
+			if(fsr&OVFL) z = y*y;
+			if(fsr&UNFL) z = (x/y)/y;
+			if(fsr&ZDIV) z = x/z;
+			if(fsr&INVAL) z = z/z;
+			_controlfp(fcr,_MCW_EM);
+		}
+	}
+	return(old&mask);
+}
+
+ulong
+getFPcontrol(void)
+{
+	ulong fcr, fcr32 = _controlfp(0,0);
+	switch(fcr32&_MCW_RC){
+		case _RC_NEAR:	fcr = RND_NR; break;
+		case _RC_DOWN:	fcr = RND_NINF; break;
+		case _RC_UP:	fcr = RND_PINF; break;
+		case _RC_CHOP:	fcr = RND_Z; break;
+	}
+	if(!(fcr32&_EM_INEXACT)) fcr |= INEX;
+	if(!(fcr32&_EM_OVERFLOW)) fcr |= OVFL;
+	if(!(fcr32&_EM_UNDERFLOW)) fcr |= UNFL;
+	if(!(fcr32&_EM_ZERODIVIDE)) fcr |= ZDIV;
+	if(!(fcr32&_EM_INVALID)) fcr |= INVAL;
+	return fcr;
+}
+
+ulong
+FPcontrol(ulong fcr, ulong mask)
+{
+	ulong old = getFPcontrol();
+	ulong fcr32 = _MCW_EM, mask32 = _MCW_RC|_MCW_EM;
+	fcr = (fcr&mask) | (old&~mask);
+	if(fcr&INEX) fcr32 ^= _EM_INEXACT;
+	if(fcr&OVFL) fcr32 ^= _EM_OVERFLOW;
+	if(fcr&UNFL) fcr32 ^= _EM_UNDERFLOW;
+	if(fcr&ZDIV) fcr32 ^= _EM_ZERODIVIDE;
+	if(fcr&INVAL) fcr32 ^= _EM_INVALID;
+	switch(fcr&RND_MASK){
+		case RND_NR:	fcr32 |= _RC_NEAR; break;
+		case RND_NINF:	fcr32 |= _RC_DOWN; break;
+		case RND_PINF:	fcr32 |= _RC_UP; break;
+		case RND_Z:	fcr32 |= _RC_CHOP; break;
+	}
+	_controlfp(fcr32,mask32);
+	return(old&mask);
+}