Fix powerpc-nofpu __fe_enabled_env and __fe_nonieee_env (bug 17261)

["Joseph S. Myers" <joseph at codesourcery dot com>]

On powerpc, floating-point environment macros are defined as pointers
to constants in the library that contain the bit-patterns of the
desired environment, instead of being magic constants cast to pointer
type.

For soft-float, the bit-patterns used for fenv_t are not laid out the
same as for hard-float.  (e500 has a third layout used; that's not an
ABI issue because these values are only meaningful within a single
process, all of whose glibc libraries must come from the same build of
glibc.)  While the __fe_dfl_env value for soft-float was appropriate
for the soft-float fenv_t representation, the other two constants had
the same bit-patterns as for hard-float.  Those bit patterns had the
effect of having exceptions already raised, causing
math/test-fenv-return to fail; this patch fixes the patterns used.
(__fe_nonieee_env also had exceptions unmasked, though they should be
masked to match hard-float semantics.  Since there is no separate
non-IEEE mode for soft-float, it's most appropriate for
__fe_nonieee_env to be the same as __fe_dfl_env; this patch makes it
an alias.)

Tested for powerpc-nofpu.

2014-08-12  Joseph Myers  <joseph@codesourcery.com>

	[BZ #17261]
	* sysdeps/powerpc/nofpu/fenv_const.c (__fe_enabled_env): Change
	value to 0.
	(__fe_nonieee_env): Define as an alias for __fe_dfl_env.

diff --git a/sysdeps/powerpc/nofpu/fenv_const.c b/sysdeps/powerpc/nofpu/fenv_const.c
index 6dc9e6f..39f53dd 100644
--- a/sysdeps/powerpc/nofpu/fenv_const.c
+++ b/sysdeps/powerpc/nofpu/fenv_const.c
@@ -27,8 +27,8 @@ const unsigned long long __fe_dfl_env __attribute__ ((aligned (8))) =
 
 /* Floating-point environment where none of the exceptions are masked.  */
 const unsigned long long __fe_enabled_env __attribute__ ((aligned (8))) =
-0xfff80000000000f8ULL;
+0x0000000000000000ULL;
 
-/* Floating-point environment with the NI bit set.  */
-const unsigned long long __fe_nonieee_env __attribute__ ((aligned (8))) =
-0xfff8000000000004ULL;
+/* Floating-point environment with the NI bit set.  No difference for
+   soft float from the default environment.  */
+strong_alias (__fe_dfl_env, __fe_nonieee_env)

-- 
Joseph S. Myers
joseph@codesourcery.com