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-rw-r--r--src/math/lrint.c28
1 files changed, 27 insertions, 1 deletions
diff --git a/src/math/lrint.c b/src/math/lrint.c
index bdca8b7c..ddee7a0d 100644
--- a/src/math/lrint.c
+++ b/src/math/lrint.c
@@ -1,5 +1,6 @@
#include <limits.h>
#include <fenv.h>
+#include <math.h>
#include "libm.h"
/*
@@ -26,7 +27,18 @@ as a double.
*/
#if LONG_MAX < 1U<<53 && defined(FE_INEXACT)
-long lrint(double x)
+#include <float.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
+#ifdef __GNUC__
+/* avoid stack frame in lrint */
+__attribute__((noinline))
+#endif
+static long lrint_slow(double x)
{
#pragma STDC FENV_ACCESS ON
int e;
@@ -38,6 +50,20 @@ long lrint(double x)
/* conversion */
return x;
}
+
+long lrint(double x)
+{
+ uint32_t abstop = asuint64(x)>>32 & 0x7fffffff;
+ uint64_t sign = asuint64(x) & (1ULL << 63);
+
+ if (abstop < 0x41dfffff) {
+ /* |x| < 0x7ffffc00, no overflow */
+ double_t toint = asdouble(asuint64(1/EPS) | sign);
+ double_t y = x + toint - toint;
+ return (long)y;
+ }
+ return lrint_slow(x);
+}
#else
long lrint(double x)
{