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

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out of date.  This patch avoids the problem of the list getting out of
date by instead having conditionals on all the (few, old) pre-i686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.

diff --git a/ChangeLog b/ChangeLog
index 8942396893e7746dfb9036cb9864e13bb29f4501..fc3fbffa231376019503c8271c3634bc955d70e2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -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.

diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index d342664c64ab7aa112b74481e6a954f0fba4f7d7..fb22d7b9d6226a92d4fd30f41d5ab149664a5c09 100644 (file)
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -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 */