Simplify hypotf infinity handling (bug 15918).

Bug 15918 points out that the handling of infinities in hypotf can be
simplified: it's enough to return the absolute value of the infinite
argument without first comparing it to the other argument and possibly
returning that other argument's absolute value.  This patch makes that
cleanup (which should not change how hypotf behaves on any input).

Tested for x86_64.

	[BZ #15918]
	* sysdeps/ieee754/flt-32/e_hypotf.c (__ieee754_hypotf): Simplify
	handling of cases where one argument is an infinity.

diff --git a/ChangeLog b/ChangeLog
index 4d6f2bb..f807e7c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2015-09-15  Joseph Myers  <joseph@codesourcery.com>
 
+       [BZ #15918]
+       * sysdeps/ieee754/flt-32/e_hypotf.c (__ieee754_hypotf): Simplify
+       handling of cases where one argument is an infinity.
+
        [BZ #18875]
        [BZ #18966]
        * sysdeps/i386/fpu/e_exp10.S (dbl_min): New object.

diff --git a/NEWS b/NEWS
index f782af3..a09ba38 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -9,12 +9,12 @@ Version 2.23
 
 * The following bugs are resolved with this release:
 
-  2542, 2543, 2558, 2898, 14341, 14912, 15786, 16141, 16517, 16519, 16520,
-  16521, 16734, 16973, 16985, 17787, 17905, 18084, 18086, 18240, 18265,
-  18370, 18421, 18480, 18525, 18610, 18618, 18647, 18661, 18674, 18675,
-  18681, 18757, 18778, 18781, 18787, 18789, 18790, 18795, 18796, 18820,
-  18823, 18824, 18863, 18870, 18873, 18875, 18887, 18921, 18952, 18961,
-  18966.
+  2542, 2543, 2558, 2898, 14341, 14912, 15786, 15918, 16141, 16517, 16519,
+  16520, 16521, 16734, 16973, 16985, 17787, 17905, 18084, 18086, 18240,
+  18265, 18370, 18421, 18480, 18525, 18610, 18618, 18647, 18661, 18674,
+  18675, 18681, 18757, 18778, 18781, 18787, 18789, 18790, 18795, 18796,
+  18820, 18823, 18824, 18863, 18870, 18873, 18875, 18887, 18921, 18952,
+  18961, 18966.
 
 * The obsolete header <regexp.h> has been removed.  Programs that require
   this header must be updated to use <regex.h> instead.

diff --git a/sysdeps/ieee754/flt-32/e_hypotf.c b/sysdeps/ieee754/flt-32/e_hypotf.c
index 8f499b5..717b82e 100644 (file)
--- a/sysdeps/ieee754/flt-32/e_hypotf.c
+++ b/sysdeps/ieee754/flt-32/e_hypotf.c
@@ -27,17 +27,9 @@ __ieee754_hypotf(float x, float y)
        GET_FLOAT_WORD(hb,y);
        hb &= 0x7fffffff;
        if (ha == 0x7f800000)
-         {
-           if (x == y)
-             return fabsf(y);
-           return fabsf(x);
-         }
+         return fabsf(x);
        else if (hb == 0x7f800000)
-         {
-           if (x == y)
-             return fabsf(x);
-           return fabsf(y);
-         }
+         return fabsf(y);
        else if (ha > 0x7f800000 || hb > 0x7f800000)
          return fabsf(x) * fabsf(y);
        else if (ha == 0)