From: Thomas Schwinge <thomas@codesourcery.com>
Date: Wed, 3 Apr 2013 20:00:21 +0000 (+0200)
Subject: [BZ #15335, #15342] Fix standard compliance.  Don't use hard-coded qNaN values.
X-Git-Tag: glibc-2.18~430
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8b43a0c9f26d5cf067119e47df9973515535673f;p=thirdparty%2Fglibc.git

[BZ #15335, #15342] Fix standard compliance.  Don't use hard-coded qNaN values.
---

diff --git a/ChangeLog b/ChangeLog
index b96a33330da..f0abe722a7e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2013-04-05  Thomas Schwinge  <thomas@codesourcery.com>
 
+	[BZ #15335, #15342]
+	* sysdeps/ieee754/dbl-64/upow.h (NaNQ): Remove definitions.
+	* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Instead, use
+	input NaN values or generate a qNaN by arithmetic operation.
+
 	* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Remove
 	unreachable code.
 
diff --git a/NEWS b/NEWS
index 8577030c626..3a39baf0fcd 100644
--- a/NEWS
+++ b/NEWS
@@ -13,7 +13,7 @@ Version 2.18
   14317, 14327, 14478, 14496, 14812, 14920, 14964, 14981, 14982, 14985,
   14994, 14996, 15003, 15006, 15020, 15023, 15036, 15054, 15055, 15062,
   15078, 15160, 15214, 15232, 15234, 15283, 15285, 15287, 15304, 15305,
-  15307, 15327, 15330, 15337.
+  15307, 15327, 15330, 15335, 15337, 15342.
 
 * CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
   #15078).
diff --git a/sysdeps/ieee754/dbl-64/e_pow.c b/sysdeps/ieee754/dbl-64/e_pow.c
index 44d6f623988..9a766e7224a 100644
--- a/sysdeps/ieee754/dbl-64/e_pow.c
+++ b/sysdeps/ieee754/dbl-64/e_pow.c
@@ -71,8 +71,9 @@ __ieee754_pow(double x, double y) {
   u.x=x;
   if (v.i[LOW_HALF] == 0) { /* of y */
     qx = u.i[HIGH_HALF]&0x7fffffff;
-    /* Checking  if x is not too small to compute */
-    if (((qx==0x7ff00000)&&(u.i[LOW_HALF]!=0))||(qx>0x7ff00000)) return NaNQ.x;
+    /* Is x a NaN?  */
+    if (((qx == 0x7ff00000) && (u.i[LOW_HALF] != 0)) || (qx > 0x7ff00000))
+      return x;
     if (y == 1.0) return x;
     if (y == 2.0) return x*x;
     if (y == -1.0) return 1.0/x;
@@ -111,7 +112,7 @@ __ieee754_pow(double x, double y) {
 
   if (x == 0) {
     if (((v.i[HIGH_HALF] & 0x7fffffff) == 0x7ff00000 && v.i[LOW_HALF] != 0)
-	|| (v.i[HIGH_HALF] & 0x7fffffff) > 0x7ff00000)
+	|| (v.i[HIGH_HALF] & 0x7fffffff) > 0x7ff00000) /* NaN */
       return y;
     if (ABS(y) > 1.0e20) return (y>0)?0:1.0/0.0;
     k = checkint(y);
@@ -124,9 +125,10 @@ __ieee754_pow(double x, double y) {
   qx = u.i[HIGH_HALF]&0x7fffffff;  /*   no sign   */
   qy = v.i[HIGH_HALF]&0x7fffffff;  /*   no sign   */
 
-  if (qx >= 0x7ff00000 && (qx > 0x7ff00000 || u.i[LOW_HALF] != 0)) return NaNQ.x;
-  if (qy >= 0x7ff00000 && (qy > 0x7ff00000 || v.i[LOW_HALF] != 0))
-    return x == 1.0 ? 1.0 : NaNQ.x;
+  if (qx >= 0x7ff00000 && (qx > 0x7ff00000 || u.i[LOW_HALF] != 0)) /* NaN */
+    return x;
+  if (qy >= 0x7ff00000 && (qy > 0x7ff00000 || v.i[LOW_HALF] != 0)) /* NaN */
+    return x == 1.0 ? 1.0 : y;
 
   /* if x<0 */
   if (u.i[HIGH_HALF] < 0) {
@@ -139,7 +141,7 @@ __ieee754_pow(double x, double y) {
       }
       else if (qx == 0x7ff00000)
 	return y < 0 ? 0.0 : INF.x;
-      return NaNQ.x;                              /* y not integer and x<0 */
+      return (x - x) / (x - x);                   /* y not integer and x<0 */
     }
     else if (qx == 0x7ff00000)
       {
diff --git a/sysdeps/ieee754/dbl-64/upow.h b/sysdeps/ieee754/dbl-64/upow.h
index 67bae1aefca..130fb3296fe 100644
--- a/sysdeps/ieee754/dbl-64/upow.h
+++ b/sysdeps/ieee754/dbl-64/upow.h
@@ -34,7 +34,6 @@
 /**/ nZERO	    = {{0x80000000, 0}},	  /* -0.0          */
 /**/ INF            = {{0x7ff00000, 0x00000000}}, /* INF           */
 /**/ nINF           = {{0xfff00000, 0x00000000}}, /* -INF          */
-/**/ NaNQ           = {{0x7ff80000, 0x00000000}}, /* NaNQ          */
 /**/ sqrt_2         = {{0x3ff6a09e, 0x667f3bcc}}, /* sqrt(2)       */
 /**/ ln2a           = {{0x3fe62e42, 0xfefa3800}}, /* ln(2) 43 bits */
 /**/ ln2b           = {{0x3d2ef357, 0x93c76730}}, /* ln(2)-ln2a    */
@@ -49,7 +48,6 @@
 /**/ nZERO	    = {{0, 0x80000000}},	  /* -0.0          */
 /**/ INF            = {{0x00000000, 0x7ff00000}}, /* INF           */
 /**/ nINF           = {{0x00000000, 0xfff00000}}, /* -INF           */
-/**/ NaNQ           = {{0x00000000, 0x7ff80000}}, /* NaNQ          */
 /**/ sqrt_2         = {{0x667f3bcc, 0x3ff6a09e}}, /* sqrt(2)       */
 /**/ ln2a           = {{0xfefa3800, 0x3fe62e42}}, /* ln(2) 43 bits */
 /**/ ln2b           = {{0x93c76730, 0x3d2ef357}}, /* ln(2)-ln2a    */