This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH 2/4] alpha: fix floor on sNaN input [committed/2.24]


From: Aurelien Jarno <aurelien@aurel32.net>

The alpha version of floor wrongly return sNaN for sNaN input. Fix that
by checking for NaN and by returning the input value added with itself
in that case.

Finally remove the code to handle inexact exception, floor should never
generate such an exception.

Changelog:
	* sysdeps/alpha/fpu/s_floor.c (__floor): Add argument with itself
	when it is a NaN.
	[_IEEE_FP_INEXACT] Remove.
	* sysdeps/alpha/fpu/s_floorf.c (__floorf): Likewise.

(cherry picked from commit 65cc568cf57156e5230db9a061645e54ff028a41)
---
 ChangeLog                    | 4 ++++
 sysdeps/alpha/fpu/s_floor.c  | 7 +++----
 sysdeps/alpha/fpu/s_floorf.c | 7 +++----
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 927e1ae9b426..77204f41bc35 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,10 @@
 	when it is a NaN.
 	[_IEEE_FP_INEXACT] Remove.
 	* sysdeps/alpha/fpu/s_ceilf.c (__ceilf): Likewise.
+	* sysdeps/alpha/fpu/s_floor.c (__floor): Add argument with itself
+	when it is a NaN.
+	[_IEEE_FP_INEXACT] Remove.
+	* sysdeps/alpha/fpu/s_floorf.c (__floorf): Likewise.
 
 2016-11-30  H.J. Lu  <hongjiu.lu@intel.com>
 
diff --git a/sysdeps/alpha/fpu/s_floor.c b/sysdeps/alpha/fpu/s_floor.c
index 1a6f8c461756..9930f6be42af 100644
--- a/sysdeps/alpha/fpu/s_floor.c
+++ b/sysdeps/alpha/fpu/s_floor.c
@@ -27,16 +27,15 @@
 double
 __floor (double x)
 {
+  if (isnan (x))
+    return x + x;
+
   if (isless (fabs (x), 9007199254740992.0))	/* 1 << DBL_MANT_DIG */
     {
       double tmp1, new_x;
 
       __asm (
-#ifdef _IEEE_FP_INEXACT
-	     "cvttq/svim %2,%1\n\t"
-#else
 	     "cvttq/svm %2,%1\n\t"
-#endif
 	     "cvtqt/m %1,%0\n\t"
 	     : "=f"(new_x), "=&f"(tmp1)
 	     : "f"(x));
diff --git a/sysdeps/alpha/fpu/s_floorf.c b/sysdeps/alpha/fpu/s_floorf.c
index 8cd80e2b42d7..015c04f40d80 100644
--- a/sysdeps/alpha/fpu/s_floorf.c
+++ b/sysdeps/alpha/fpu/s_floorf.c
@@ -26,6 +26,9 @@
 float
 __floorf (float x)
 {
+  if (isnanf (x))
+    return x + x;
+
   if (isless (fabsf (x), 16777216.0f))	/* 1 << FLT_MANT_DIG */
     {
       /* Note that Alpha S_Floating is stored in registers in a
@@ -36,11 +39,7 @@ __floorf (float x)
       float tmp1, tmp2, new_x;
 
       __asm ("cvtst/s %3,%2\n\t"
-#ifdef _IEEE_FP_INEXACT
-	     "cvttq/svim %2,%1\n\t"
-#else
 	     "cvttq/svm %2,%1\n\t"
-#endif
 	     "cvtqt/m %1,%0\n\t"
 	     : "=f"(new_x), "=&f"(tmp1), "=&f"(tmp2)
 	     : "f"(x));
-- 
2.11.0.rc2


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]