alpha: Fix isnan

The isunordered formulation raises SIGFPE for SNaN.

2 files changed, 3 insertions, 24 deletions

diff --git a/sysdeps/alpha/fpu/bits/mathinline.h b/sysdeps/alpha/fpu/bits/mathinline.h
index 3d64b56107..83f3b4ad0a 100644
--- a/sysdeps/alpha/fpu/bits/mathinline.h
+++ b/sysdeps/alpha/fpu/bits/mathinline.h
@@ -120,29 +120,6 @@ __NTH (__signbitl (long double __x))
   return __builtin_signbitl (__x);
 #endif
 }
-
-/* Test for NaN.  Used in the isnan() macro.  */
-
-__MATH_INLINE int
-__NTH (__isnanf (float __x))
-{
-  return isunordered (__x, __x);
-}
-
-__MATH_INLINE int
-__NTH (__isnan (double __x))
-{
-  return isunordered (__x, __x);
-}
-
-#ifndef __NO_LONG_DOUBLE_MATH
-__MATH_INLINE int
-__NTH (__isnanl (long double __x))
-{
-  return isunordered (__x, __x);
-}
-#endif
-
 #endif /* C99 */
 
 #endif /* __NO_MATH_INLINES */
diff --git a/sysdeps/alpha/fpu/s_isnan.c b/sysdeps/alpha/fpu/s_isnan.c
index adfb4ccf36..d664f0cb10 100644
--- a/sysdeps/alpha/fpu/s_isnan.c
+++ b/sysdeps/alpha/fpu/s_isnan.c
@@ -31,7 +31,9 @@
 int
 __isnan (double x)
 {
-  return isunordered (x, x);
+  uint64_t ix;
+  EXTRACT_WORDS64 (ix, x);
+  return ix * 2 > 0xffe0000000000000ul;
 }
 
 hidden_def (__isnan)