Index: fusl/src/math/round.c |
diff --git a/fusl/src/math/round.c b/fusl/src/math/round.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..130d58d2571e77cc15a67b355010e11c5ebebe91 |
--- /dev/null |
+++ b/fusl/src/math/round.c |
@@ -0,0 +1,35 @@ |
+#include "libm.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 round(double x) |
+{ |
+ union {double f; uint64_t i;} u = {x}; |
+ int e = u.i >> 52 & 0x7ff; |
+ double_t y; |
+ |
+ if (e >= 0x3ff+52) |
+ return x; |
+ if (u.i >> 63) |
+ x = -x; |
+ if (e < 0x3ff-1) { |
+ /* raise inexact if x!=0 */ |
+ FORCE_EVAL(x + toint); |
+ return 0*u.f; |
+ } |
+ y = x + toint - toint - x; |
+ if (y > 0.5) |
+ y = y + x - 1; |
+ else if (y <= -0.5) |
+ y = y + x + 1; |
+ else |
+ y = y + x; |
+ if (u.i >> 63) |
+ y = -y; |
+ return y; |
+} |