[COMMITTED 2/2] alpha: Fix isnan

[Richard Henderson]

The isunordered formulation raises SIGFPE for SNaN.
---
 ChangeLog                           |  4 ++++
 sysdeps/alpha/fpu/bits/mathinline.h | 23 -----------------------
 sysdeps/alpha/fpu/s_isnan.c         |  4 +++-
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 39b6b54..a079a18 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2014-07-01  Richard henderson  <rth@redhat.com>
 
+	* sysdeps/alpha/fpu/bits/mathinline.h (__isnanf): Remove.
+	(__isnan, __isnanl): Remove.
+	* sysdeps/alpha/fpu/s_isnan.c (__isnan): Use integer arithmetic.
+
 	* sysdeps/alpha/fpu/libm-test-ulps: Update.
 
 2014-07-01  Stefan Liebler  <stli@linux.vnet.ibm.com>
diff --git a/sysdeps/alpha/fpu/bits/mathinline.h b/sysdeps/alpha/fpu/bits/mathinline.h
index 3d64b56..83f3b4a 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 adfb4cc..d664f0c 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)
-- 
1.9.3