Feat: added math library

Used Plan9's libc as starting point. This cleans up dangling references
due to loss of libc.

1 files changed, 54 insertions, 0 deletions

diff --git a/src/base/math/nan.c b/src/base/math/nan.c
new file mode 100644
index 0000000..c1f85c2
--- /dev/null
+++ b/src/base/math/nan.c
@@ -0,0 +1,54 @@
+#include <u.h>
+#include <base.h>
+
+#define	NANEXP	(2047<<20)
+#define	NANMASK	(2047<<20)
+#define	NANSIGN	(1<<31)
+
+double
+math·NaN(void)
+{
+	sys·DoubleWord a;
+
+	a.hi = NANEXP;
+	a.lo = 1;
+	return a.x;
+}
+
+int
+math·isNaN(double d)
+{
+	sys·DoubleWord a;
+
+	a.x = d;
+	if((a.hi & NANMASK) != NANEXP)
+		return 0;
+	return !math·isInf(d, 0);
+}
+
+double
+math·Inf(int sign)
+{
+	sys·DoubleWord a;
+
+	a.hi = NANEXP;
+	a.lo = 0;
+	if(sign < 0)
+		a.hi |= NANSIGN;
+	return a.x;
+}
+
+int
+math·isInf(double d, int sign)
+{
+	sys·DoubleWord a;
+
+	a.x = d;
+	if(a.lo != 0)
+		return 0;
+	if(a.hi == NANEXP)
+		return sign >= 0;
+	if(a.hi == (NANEXP|NANSIGN))
+		return sign <= 0;
+	return 0;
+}