[PATCH 1/4] alpha: add the denormal trap enable bit to FE_NOMASK_ENV

FE_NOMASK_ENV is the floating-point environment in which no exception is
masked, so it must enable every exception that FE_ALL_EXCEPT covers.  On
Alpha that includes the GNU extension FE_DENORMAL, whose SWCR trap enable
bit is IEEE_TRAP_ENABLE_DNO (bit 6).

The constant only set bits 1 through 5 (INV, DZE, OVF, UNF and INE), so
after fesetenv (FE_NOMASK_ENV) a subsequent fegetexcept () returned
0x3e0000 rather than FE_ALL_EXCEPT (0x7e0000), and denormal exceptions
stayed masked.  Set bit 6 as well.

Fixes math/test-fenv-return on alpha.
---
 sysdeps/alpha/fpu/bits/fenv.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git ./sysdeps/alpha/fpu/bits/fenv.h ./sysdeps/alpha/fpu/bits/fenv.h
index b1135f1f0a..530f298914 100644
--- ./sysdeps/alpha/fpu/bits/fenv.h
+++ ./sysdeps/alpha/fpu/bits/fenv.h
@@ -121,7 +121,7 @@ typedef unsigned long int fenv_t;
 
 #ifdef __USE_GNU
 /* Floating-point environment where none of the exceptions are masked.  */
-# define FE_NOMASK_ENV	((const fenv_t *) 0x880000000000003eUL)
+# define FE_NOMASK_ENV	((const fenv_t *) 0x880000000000007eUL)
 
 /* Floating-point environment with (processor-dependent) non-IEEE floating
    point.  In this case, mapping denormals to zero.  */
-- 
2.54.0