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Invert sense of list of i686-class processors in sysdeps/x86/cpu-features.h.

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I noticed that sysdeps/x86/cpu-features.h had conditionals on whether
to define HAS_CPUID, HAS_I586 and HAS_I686 with a long list of
preprocessor macros for i686-and-later processors which however was
out of date.  This patch avoids the problem of the list getting out of
date by instead having conditionals on all the (few, old) pre-i686
processors for which GCC has preprocessor macros, rather than the
(many, expanding list) i686-and-later processors.  It seems HAS_I586
and HAS_I686 are unused so the only effect of these macros being
missing is that 32-bit glibc built for one of these processors would
end up doing runtime detection of CPUID availability.

i386 builds are prevented by a configure test so there is no need to
allow for them here.  __geode__ (no long nops?) and __k6__ (no CMOV,
at least according to GCC) are conservatively handled as i586, not
i686, here (as noted above, this is a theoretical distinction at
present in that only HAS_CPUID appears to be used).

Tested for x86.

	* sysdeps/x86/cpu-features.h [__geode__ || __k6__]: Handle like
	[__i586__ || __pentium__].
	[__i486__]: Handle explicitly.
	(HAS_CPUID): Define to 1 if above macros are undefined.
	(HAS_I586): Likewise.
	(HAS_I686): Likewise.
This commit is contained in:
Joseph Myers 2018-09-20 12:43:41 +00:00
parent db9a8ad4ff
commit d90c9b1a12
2 changed files with 16 additions and 18 deletions
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9
ChangeLog
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@ -1,3 +1,12 @@
2018-09-20 Joseph Myers <joseph@codesourcery.com>
* sysdeps/x86/cpu-features.h [__geode__ || __k6__]: Handle like
[__i586__ || __pentium__].
[__i486__]: Handle explicitly.
(HAS_CPUID): Define to 1 if above macros are undefined.
(HAS_I586): Likewise.
(HAS_I686): Likewise.
2018-09-20 Florian Weimer <fweimer@redhat.com>
* misc/tst-gethostid.c: New file.

25
sysdeps/x86/cpu-features.h
View File

@ -257,30 +257,19 @@ extern const struct cpu_features *__get_cpu_features (void)
#ifdef __x86_64__
# define HAS_CPUID 1
#elif defined __i586__ || defined __pentium__
#elif (defined __i586__ || defined __pentium__ \
|| defined __geode__ || defined __k6__)
# define HAS_CPUID 1
# define HAS_I586 1
# define HAS_I686 HAS_ARCH_FEATURE (I686)
#elif (defined __i686__ || defined __pentiumpro__ \
|| defined __pentium4__ || defined __nocona__ \
|| defined __atom__ || defined __core2__ \
|| defined __corei7__ || defined __corei7_avx__ \
|| defined __core_avx2__ || defined __nehalem__ \
|| defined __sandybridge__ || defined __haswell__ \
|| defined __knl__ || defined __bonnell__ \
|| defined __silvermont__ \
|| defined __k6__ || defined __k8__ \
|| defined __athlon__ || defined __amdfam10__ \
|| defined __bdver1__ || defined __bdver2__ \
|| defined __bdver3__ || defined __bdver4__ \
|| defined __btver1__ || defined __btver2__)
# define HAS_CPUID 1
# define HAS_I586 1
# define HAS_I686 1
#else
#elif defined __i486__
# define HAS_CPUID 0
# define HAS_I586 HAS_ARCH_FEATURE (I586)
# define HAS_I686 HAS_ARCH_FEATURE (I686)
#else
# define HAS_CPUID 1
# define HAS_I586 1
# define HAS_I686 1
#endif
#endif /* cpu_features_h */