From: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
Date: Mon, 6 May 2013 19:40:17 +0000 (-0500)
Subject: PowerPC: fix hypot/hypof FP exceptions
X-Git-Tag: glibc-2.18~332
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=16e616a72f9ac247520c0c7da99b99e229facdf9;p=thirdparty%2Fglibc.git

PowerPC: fix hypot/hypof FP exceptions

This patch fixes hypot/hypotf spurious floating-point exceptions
generate by internal operations.
---

diff --git a/ChangeLog b/ChangeLog
index 1c43908d626..4bf30b6c570 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2013-05-06  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
+
+	[BZ #15418]
+	[BZ #15419]
+	* sysdeps/powerpc/fpu/e_hypot.c: Fix spurious FP exception generated by
+	internal tests.
+	* sysdeps/powerpc/fpu/e_hypotf.c: Likewise.
+
 2013-05-06  Roland McGrath  <roland@hack.frob.com>
 
 	* elf/dl-writev.h: New file.
diff --git a/NEWS b/NEWS
index ce654c1e5c9..95a4e4f4c35 100644
--- a/NEWS
+++ b/NEWS
@@ -16,7 +16,7 @@ Version 2.18
   15084, 15085, 15086, 15160, 15214, 15221, 15232, 15234, 15283, 15285,
   15287, 15304, 15305, 15307, 15309, 15327, 15330, 15335, 15336, 15337,
   15342, 15346, 15361, 15366, 15380, 15394, 15405, 15406, 15409, 15416,
-  15423.
+  15418, 15419, 15423.
 
 * CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
   #15078).
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 4e1eb72919a..7afa46dba82 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -9159,6 +9159,7 @@ hypot_test (void)
   TEST_ff_f (hypot, 0.75L, 1.25L, 1.45773797371132511771853821938639577L);
 
   TEST_ff_f (hypot, 1.0L, 0x1p-61L, 1.0L);
+  TEST_ff_f (hypot, 0x1p+0L, 0x1.fp-129L, 0x1p+0L);
 #if defined TEST_LDOUBLE && LDBL_MANT_DIG >= 106
   TEST_ff_f (hypot, 0x1.23456789abcdef0123456789ab8p-500L, 0x1.23456789abcdef0123456789ab8p-500L, 4.9155782399407039128612180934736799735113e-151L);
 #endif
@@ -9170,6 +9171,7 @@ hypot_test (void)
 
 #if !defined TEST_FLOAT && !(defined TEST_DOUBLE && defined TEST_INLINE)
   TEST_ff_f (hypot, 0x3p1021L, 0x4p1021L, 0x5p1021L);
+  TEST_ff_f (hypot, 0x1p+0L, 0x0.3ep-1022L, 0x1p+0L);
 #endif
 
 #if defined TEST_LDOUBLE && LDBL_MAX_EXP >= 16384 && !defined TEST_INLINE
diff --git a/sysdeps/powerpc/fpu/e_hypot.c b/sysdeps/powerpc/fpu/e_hypot.c
index f23633946f6..d8568d6e3f7 100644
--- a/sysdeps/powerpc/fpu/e_hypot.c
+++ b/sysdeps/powerpc/fpu/e_hypot.c
@@ -26,6 +26,7 @@ static const double two600  = 4.149515568880993e+180;
 static const double two1022 = 4.49423283715579e+307;
 static const double twoM500 = 3.054936363499605e-151;
 static const double twoM600 = 2.4099198651028841e-181;
+static const double two60factor = 1.5592502418239997e+290;
 static const double pdnum   = 2.225073858507201e-308;
 
 /* __ieee754_hypot(x,y)
@@ -87,9 +88,20 @@ __ieee754_hypot (double x, double y)
       x = y;
       y = t;
     }
-  if (y == 0.0 || (x / y) > two60)
+  if (y == 0.0)
+    return x;
+  /* if y is higher enough, y * 2^60 might overflow. The tests if
+     y >= 1.7976931348623157e+308/2^60 (two60factor) and uses the
+     appropriate check to avoid the overflow exception generation.  */
+  if (y > two60factor)
     {
-      return x + y;
+      if ((x / y) > two60)
+	return x + y;
+    }
+  else
+    {
+      if (x > (y * two60))
+	return x + y;
     }
   if (x > two500)
     {
diff --git a/sysdeps/powerpc/fpu/e_hypotf.c b/sysdeps/powerpc/fpu/e_hypotf.c
index e97f0c35e39..93055afce55 100644
--- a/sysdeps/powerpc/fpu/e_hypotf.c
+++ b/sysdeps/powerpc/fpu/e_hypotf.c
@@ -69,22 +69,8 @@ static const float two30  = 1.0737418e09;
 float
 __ieee754_hypotf (float x, float y)
 {
-  x = fabsf (x);
-  y = fabsf (y);
-
   TEST_INF_NAN (x, y);
 
-  if (y > x)
-    {
-      float t = y;
-      y = x;
-      x = t;
-    }
-  if (y == 0.0 || (x / y) > two30)
-    {
-      return x + y;
-    }
-
   return __ieee754_sqrt ((double) x * x + (double) y * y);
 }
 strong_alias (__ieee754_hypotf, __hypotf_finite)