[glibc] alpha: add the denormal trap enable bit to FE_NOMASK_ENV

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8e41f6008df3b5d56df199e8b4d19891666857a4

commit 8e41f6008df3b5d56df199e8b4d19891666857a4
Author: Matt Turner <[email protected]>
Date:   Mon Aug 3 19:55:06 2026 -0400

    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.
    
    Reviewed-by: Adhemerval Zanella  <[email protected]>

Diff:
---
 sysdeps/alpha/fpu/bits/fenv.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sysdeps/alpha/fpu/bits/fenv.h b/sysdeps/alpha/fpu/bits/fenv.h
index b1135f1f0a..530f298914 100644
--- a/sysdeps/alpha/fpu/bits/fenv.h
+++ b/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.  */