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| author | Joseph Myers <joseph@codesourcery.com> | 2018-02-28 21:55:51 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2018-02-28 21:55:51 +0000 |
| commit | e2bcf6a8551c6b6a7eeed8f84be42b29eef4d0e2 (patch) | |
| tree | 002d326503070320fc59c589ee532b21d2ee859d /sysdeps/i386 | |
| parent | 000f290ff179c9910f09b7f76797bdab575abb15 (diff) | |
| download | glibc-e2bcf6a8551c6b6a7eeed8f84be42b29eef4d0e2.tar.gz glibc-e2bcf6a8551c6b6a7eeed8f84be42b29eef4d0e2.tar.xz glibc-e2bcf6a8551c6b6a7eeed8f84be42b29eef4d0e2.zip | |
Fix i386 fenv_private.h float128 for 32-bit --with-fpmath=sse (bug 22902).
As discussed in bug 22902, the i386 fenv_private.h implementation has problems for float128 for the case of 32-bit glibc built with libgcc from GCC configured using --with-fpmath=sse. The optimized floating-point state handling in fenv_private.h needs to know which floating-point state - x87 or SSE - is used for each floating-point type, so that only one state needs updating / testing for libm code using that state internally. On 32-bit x86, the x87 rounding mode is always used for float128, but the x87 exception flags are only used when libgcc is built using x87 floating-point arithmetic; if libgcc is built for SSE arithmetic, the SSE exception flags are used. The choice of arithmetic with which libgcc is built is independent of that with which glibc is built. Thus, since glibc cannot tell the choice used in libgcc, the default implementations of libc_feholdexcept_setroundf128 and libc_feupdateenv_testf128 (which use the <fenv.h> functions, thus using both x87 and SSE state on processors that have both) need to be used; this patch updates the code accordingly. Tested for 32-bit x86; HJ reports testing in the --with-fpmath=sse case. [BZ #22902] * sysdeps/i386/fpu/fenv_private.h [!__x86_64__] (libc_feholdexcept_setroundf128): New macro. [!__x86_64__] (libc_feupdateenv_testf128): Likewise.
Diffstat (limited to 'sysdeps/i386')
| -rw-r--r-- | sysdeps/i386/fpu/fenv_private.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/fenv_private.h b/sysdeps/i386/fpu/fenv_private.h index a258f48e07..357613a500 100644 --- a/sysdeps/i386/fpu/fenv_private.h +++ b/sysdeps/i386/fpu/fenv_private.h @@ -339,6 +339,12 @@ libc_feresetround_387 (fenv_t *e) SET_RESTORE_ROUND_GENERIC (RM, libc_feholdsetround_sse, libc_feresetround_sse) # define libc_feholdexcept_setroundf128 libc_feholdexcept_setround_sse # define libc_feupdateenv_testf128 libc_feupdateenv_test_sse +#else +/* The 387 rounding mode is used by soft-fp for 32-bit, but whether + 387 or SSE exceptions are used depends on whether libgcc was built + for SSE math, which is not known when glibc is being built. */ +# define libc_feholdexcept_setroundf128 default_libc_feholdexcept_setround +# define libc_feupdateenv_testf128 default_libc_feupdateenv_test #endif /* We have support for rounding mode context. */ |