[PATCH] fmin/fmax behaviour on NaNs

[Stephen Huw CLARKE <stephen dot clarke at st dot com>]

The implementations of fmax and fmin in newlib/libm/common
appear not to conform to section F.9.9.2/3 of the C99 spec.

That spec. states:
"If just one argument is a NaN, the fmax functions return the
other argument (if both arguments are NaNs, the functions
return a NaN)."

The following patch fixes this.

Steve.

--- newlib/libm/common/orig-sf_fmax.c	2002-06-07 22:59:56.000000000 +0100
+++ newlib/libm/common/sf_fmax.c	2005-08-08 17:13:08.000000000 +0100
@@ -15,9 +15,9 @@
 #endif
 {
   if (__fpclassifyf(x) == FP_NAN)
-    return x;
-  if (__fpclassifyf(y) == FP_NAN)
     return y;
+  if (__fpclassifyf(y) == FP_NAN)
+    return x;
   
   return x > y ? x : y;
 }
--- newlib/libm/common/orig-s_fmax.c	2002-06-07 22:59:56.000000000 +0100
+++ newlib/libm/common/s_fmax.c	2005-08-08 17:07:04.000000000 +0100
@@ -17,9 +17,9 @@
 #endif
 {
   if (__fpclassifyd(x) == FP_NAN)
-    return x;
-  if (__fpclassifyd(y) == FP_NAN)
     return y;
+  if (__fpclassifyd(y) == FP_NAN)
+    return x;
   
   return x > y ? x : y;
 }
--- newlib/libm/common/orig-sf_fmin.c	2002-06-07 22:59:56.000000000 +0100
+++ newlib/libm/common/sf_fmin.c	2005-08-08 17:24:57.000000000 +0100
@@ -15,9 +15,9 @@
 #endif
 {
   if (__fpclassifyf(x) == FP_NAN)
-    return x;
-  if (__fpclassifyf(y) == FP_NAN)
     return y;
+  if (__fpclassifyf(y) == FP_NAN)
+    return x;
   
   return x < y ? x : y;
 }
--- newlib/libm/common/orig-s_fmin.c	2002-06-07 22:59:56.000000000 +0100
+++ newlib/libm/common/s_fmin.c	2005-08-08 17:07:16.000000000 +0100
@@ -17,9 +17,9 @@
 #endif
 {
   if (__fpclassifyd(x) == FP_NAN)
-    return x;
-  if (__fpclassifyd(y) == FP_NAN)
     return y;
+  if (__fpclassifyd(y) == FP_NAN)
+    return x;
   
   return x < y ? x : y;
 }

Attachment: fmax.patch
Description: Binary data