make lrint and llrint functions work without fenv support

[musl] / src / math / llrintl.c

diff --git a/src/math/llrintl.c b/src/math/llrintl.c
index ec2cf86..32bb8b0 100644 (file)
--- a/src/math/llrintl.c
+++ b/src/math/llrintl.c
@@ -1,16 +1,35 @@
-#include <math.h>
-#include <float.h>
+#include <limits.h>
+#include <fenv.h>
+#include "libm.h"
+
 
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
 long long llrintl(long double x)
 {
        return llrint(x);
 }
-#else
-#define type            long double
-#define roundit         rintl
-#define dtype           long long
-#define fn              llrintl
+#elif defined(FE_INEXACT)
+/*
+see comments in lrint.c
+
+Note that if LLONG_MAX == 0x7fffffffffffffff && LDBL_MANT_DIG == 64
+then x == 2**63 - 0.5 is the only input that overflows and
+raises inexact (with tonearest or upward rounding mode)
+*/
+long long llrintl(long double x)
+{
+       int e;
 
-#include "lrint.c"
+       e = fetestexcept(FE_INEXACT);
+       x = rintl(x);
+       if (!e && (x > LLONG_MAX || x < LLONG_MIN))
+               feclearexcept(FE_INEXACT);
+       /* conversion */
+       return x;
+}
+#else
+long long llrintl(long double x)
+{
+       return rintl(x);
+}
 #endif