Import sources from 2011-03-30 iso image

1 files changed, 30 insertions, 0 deletions

diff --git a/sys/src/ape/lib/ap/stdio/pow10.c b/sys/src/ape/lib/ap/stdio/pow10.c
new file mode 100755
index 000000000..fc2aec265
--- /dev/null
+++ b/sys/src/ape/lib/ap/stdio/pow10.c
@@ -0,0 +1,30 @@
+#include <errno.h>
+#include <float.h>
+#include <math.h>
+
+static	long	tab[] =
+{
+	1L, 10L, 100L, 1000L, 10000L,
+	100000L, 1000000L, 10000000L
+};
+
+double
+pow10(int n)
+{
+	int m;
+
+	if(n > DBL_MAX_10_EXP){
+		errno = ERANGE;
+		return HUGE_VAL;
+	}
+	if(n < DBL_MIN_10_EXP){
+		errno = ERANGE;
+		return 0.0;
+	}
+	if(n < 0)
+		return 1/pow10(-n);
+	if(n < sizeof(tab)/sizeof(tab[0]))
+		return tab[n];
+	m = n/2;
+	return pow10(m) * pow10(n-m);
+}