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-rw-r--r--ChangeLog12
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/Makefile5
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c9
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/tst-strtold-ldbl-128ibm.c85
4 files changed, 111 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index ff18106560..b911aecafb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2015-11-13  Joseph Myers  <joseph@codesourcery.com>
+
+	[BZ #14551]
+	* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c: Include <errno.h>.
+	(__mpn_construct_long_double): If high part overflows to infinity,
+	set errno and recompute overflowed result of the correct sign.
+	* sysdeps/ieee754/ldbl-128ibm/Makefile
+	[$(subdir) = stdlib] (tests): Add tst-strtold-ldbl-128ibm.
+	[$(subdir) = stdlib] ($(objpfx)tst-strtold-ldbl-128ibm): Depend on
+	$(libm).
+	* sysdeps/ieee754/ldbl-128ibm/tst-strtold-ldbl-128ibm.c: New file.
+
 2015-11-12  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #15479]
diff --git a/sysdeps/ieee754/ldbl-128ibm/Makefile b/sysdeps/ieee754/ldbl-128ibm/Makefile
index 8e1e2e6ae5..5591814824 100644
--- a/sysdeps/ieee754/ldbl-128ibm/Makefile
+++ b/sysdeps/ieee754/ldbl-128ibm/Makefile
@@ -3,3 +3,8 @@
 # when -mlong-double-64 is not used).
 long-double-fcts = yes
 sysdep-CFLAGS += -mlong-double-128
+
+ifeq ($(subdir),stdlib)
+tests += tst-strtold-ldbl-128ibm
+$(objpfx)tst-strtold-ldbl-128ibm: $(libm)
+endif
diff --git a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c b/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c
index bacb2cc98b..90dae9325d 100644
--- a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c
@@ -18,6 +18,7 @@
 #include "gmp.h"
 #include "gmp-impl.h"
 #include <ieee754.h>
+#include <errno.h>
 #include <float.h>
 #include <math.h>
 
@@ -111,6 +112,14 @@ __mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign)
 	    {
 	      hi >>= 1;
 	      u.d[0].ieee.exponent++;
+	      if (u.d[0].ieee.exponent == IEEE754_DOUBLE_BIAS + DBL_MAX_EXP)
+		{
+		  /* Overflow.  The appropriate overflowed result must
+		     be produced (if an infinity, that means the low
+		     part must be zero).  */
+		  __set_errno (ERANGE);
+		  return (sign ? -LDBL_MAX : LDBL_MAX) * LDBL_MAX;
+		}
 	    }
 	  u.d[1].ieee.negative = !sign;
 	  lo = (1LL << 53) - lo;
diff --git a/sysdeps/ieee754/ldbl-128ibm/tst-strtold-ldbl-128ibm.c b/sysdeps/ieee754/ldbl-128ibm/tst-strtold-ldbl-128ibm.c
new file mode 100644
index 0000000000..382071dfa1
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/tst-strtold-ldbl-128ibm.c
@@ -0,0 +1,85 @@
+/* Test for ldbl-128ibm strtold overflow to infinity (bug 14551).
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fenv.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static int
+test_strtold_value (const char *s, double exp_hi, double exp_lo, int exp_exc,
+		    int exp_errno)
+{
+  int result = 0;
+  union { long double ld; double d[2]; } x;
+  feclearexcept (FE_ALL_EXCEPT);
+  errno = 0;
+  x.ld = strtold (s, NULL);
+  int exc = fetestexcept (FE_ALL_EXCEPT);
+  int new_errno = errno;
+  printf ("strtold (\"%s\") returned (%a, %a), exceptions 0x%x, errno %d\n",
+	  s, x.d[0], x.d[1], exc, new_errno);
+  if (x.d[0] == exp_hi)
+    printf ("PASS: strtold (\"%s\") high == %a\n", s, exp_hi);
+  else
+    {
+      printf ("FAIL: strtold (\"%s\") high == %a\n", s, exp_hi);
+      result = 1;
+    }
+  if (x.d[1] == exp_lo)
+    printf ("PASS: strtold (\"%s\") low == %a\n", s, exp_lo);
+  else
+    {
+      printf ("FAIL: strtold (\"%s\") low == %a\n", s, exp_lo);
+      result = 1;
+    }
+  if (exc == exp_exc)
+    printf ("PASS: strtold (\"%s\") exceptions 0x%x\n", s, exp_exc);
+  else
+    {
+      printf ("FAIL: strtold (\"%s\") exceptions 0x%x\n", s, exp_exc);
+      result = 1;
+    }
+  if (new_errno == exp_errno)
+    printf ("PASS: strtold (\"%s\") errno %d\n", s, exp_errno);
+  else
+    {
+      printf ("FAIL: strtold (\"%s\") errno %d\n", s, exp_errno);
+      result = 1;
+    }
+  return result;
+}
+
+static int
+do_test (void)
+{
+  int result = 0;
+  result |= test_strtold_value ("0x1.fffffffffffff8p+1023", INFINITY, 0,
+				FE_OVERFLOW | FE_INEXACT, ERANGE);
+  result |= test_strtold_value ("-0x1.fffffffffffff8p+1023", -INFINITY, 0,
+				FE_OVERFLOW | FE_INEXACT, ERANGE);
+  result |= test_strtold_value ("0x1.ffffffffffffffp+1023", INFINITY, 0,
+				FE_OVERFLOW | FE_INEXACT, ERANGE);
+  result |= test_strtold_value ("-0x1.ffffffffffffffp+1023", -INFINITY, 0,
+				FE_OVERFLOW | FE_INEXACT, ERANGE);
+  return result;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../../../test-skeleton.c"