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-rw-r--r--lib/mlibc/options/ansi/musl-generic-math/rint.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/rint.c b/lib/mlibc/options/ansi/musl-generic-math/rint.c
new file mode 100644
index 0000000..fbba390
--- /dev/null
+++ b/lib/mlibc/options/ansi/musl-generic-math/rint.c
@@ -0,0 +1,28 @@
+#include <float.h>
+#include <math.h>
+#include <stdint.h>
+
+#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1
+#define EPS DBL_EPSILON
+#elif FLT_EVAL_METHOD==2
+#define EPS LDBL_EPSILON
+#endif
+static const double_t toint = 1/EPS;
+
+double rint(double x)
+{
+ union {double f; uint64_t i;} u = {x};
+ int e = u.i>>52 & 0x7ff;
+ int s = u.i>>63;
+ double_t y;
+
+ if (e >= 0x3ff+52)
+ return x;
+ if (s)
+ y = x - toint + toint;
+ else
+ y = x + toint - toint;
+ if (y == 0)
+ return s ? -0.0 : 0;
+ return y;
+}