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-rw-r--r--src/stdlib/frexp.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/src/stdlib/frexp.c b/src/stdlib/frexp.c
new file mode 100644
index 00000000..ae82cb30
--- /dev/null
+++ b/src/stdlib/frexp.c
@@ -0,0 +1,23 @@
+#include <math.h>
+#include <inttypes.h>
+
+double frexp(double x, int *e)
+{
+ union { double d; uint64_t i; } y = { x };
+ int ee = y.i>>52 & 0x7ff;
+
+ if (!ee) {
+ if (x) {
+ x = frexp(x*0x1p64, e);
+ *e -= 64;
+ } else *e = 0;
+ return x;
+ } else if (ee == 0x7ff) {
+ return x;
+ }
+
+ *e = ee - 0x3fe;
+ y.i &= 0x800fffffffffffffull;
+ y.i |= 0x3fe0000000000000ull;
+ return y.d;
+}