min and max: NaNs beat infinities, per R6RS errata.

[bpt/guile.git] / libguile / numbers.c

diff --git a/libguile/numbers.c b/libguile/numbers.c
index d09b7c5..6107310 100644 (file)
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -7219,17 +7219,16 @@ scm_max (SCM x, SCM y)
          double xx = SCM_REAL_VALUE (x);
          double yy = SCM_REAL_VALUE (y);
 
-         /* For purposes of max: +inf.0 > nan > everything else, per R6RS */
+         /* For purposes of max: nan > +inf.0 > everything else,
+             per the R6RS errata */
          if (xx > yy)
            return x;
          else if (SCM_LIKELY (xx < yy))
            return y;
          /* If neither (xx > yy) nor (xx < yy), then
             either they're equal or one is a NaN */
-         else if (SCM_UNLIKELY (isnan (xx)))
-           return DOUBLE_IS_POSITIVE_INFINITY (yy) ? y : x;
-         else if (SCM_UNLIKELY (isnan (yy)))
-           return DOUBLE_IS_POSITIVE_INFINITY (xx) ? x : y;
+         else if (SCM_UNLIKELY (xx != yy))
+           return (xx != xx) ? x : y;  /* Return the NaN */
          /* xx == yy, but handle signed zeroes properly */
          else if (double_is_non_negative_zero (yy))
            return y;
@@ -7379,17 +7378,16 @@ scm_min (SCM x, SCM y)
          double xx = SCM_REAL_VALUE (x);
          double yy = SCM_REAL_VALUE (y);
 
-         /* For purposes of min: -inf.0 < nan < everything else, per R6RS */
+         /* For purposes of min: nan < -inf.0 < everything else,
+             per the R6RS errata */
          if (xx < yy)
            return x;
          else if (SCM_LIKELY (xx > yy))
            return y;
          /* If neither (xx < yy) nor (xx > yy), then
             either they're equal or one is a NaN */
-         else if (SCM_UNLIKELY (isnan (xx)))
-           return DOUBLE_IS_NEGATIVE_INFINITY (yy) ? y : x;
-         else if (SCM_UNLIKELY (isnan (yy)))
-           return DOUBLE_IS_NEGATIVE_INFINITY (xx) ? x : y;
+         else if (SCM_UNLIKELY (xx != yy))
+           return (xx != xx) ? x : y;  /* Return the NaN */
          /* xx == yy, but handle signed zeroes properly */
          else if (double_is_non_negative_zero (xx))
            return y;