I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
1. Divide architecture features into the usable features and the preferred
features. The usable features are for correctness and can be exported in
a stable ABI. The preferred features are for performance and only for
glibc internal use.
2. Change struct cpu_features to
struct cpu_features
{
struct cpu_features_basic basic;
unsigned int *usable_p;
struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
unsigned int usable[USABLE_FEATURE_INDEX_MAX];
unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
...
};
and initialize usable_p to pointer to the usable arary so that
struct cpu_features
{
struct cpu_features_basic basic;
unsigned int *usable_p;
struct cpuid_registers cpuid[COMMON_CPUID_INDEX_MAX];
};
can be exported via a stable ABI. The cpuid and usable arrays can be
expanded with backward binary compatibility for both .o and .so files.
3. Add COMMON_CPUID_INDEX_7_ECX_1 for AVX512_BF16.
4. Detect ENQCMD, PKS, AVX512_VP2INTERSECT, MD_CLEAR, SERIALIZE, HYBRID,
TSXLDTRK, L1D_FLUSH, CORE_CAPABILITIES and AVX512_BF16.
5. Rename CAPABILITIES to ARCH_CAPABILITIES.
6. Check if AVX512_VP2INTERSECT, AVX512_BF16 and PKU are usable.
7. Update CPU feature detection test.
index_* and bit_* macros are used to access cpuid and feature arrays o
struct cpu_features. It is very easy to use bits and indices of cpuid
array on feature array, especially in assembly codes. For example,
sysdeps/i386/i686/multiarch/bcopy.S has
HAS_CPU_FEATURE (Fast_Rep_String)
which should be
HAS_ARCH_FEATURE (Fast_Rep_String)
We change index_* and bit_* to index_cpu_*/index_arch_* and
bit_cpu_*/bit_arch_* so that we can catch such error at build time.
[BZ #19762]
* sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
(EXTRA_LD_ENVVARS): Add _arch_ to index_*/bit_*.
* sysdeps/x86/cpu-features.c (init_cpu_features): Likewise.
* sysdeps/x86/cpu-features.h (bit_*): Renamed to ...
(bit_arch_*): This for feature array.
(bit_*): Renamed to ...
(bit_cpu_*): This for cpu array.
(index_*): Renamed to ...
(index_arch_*): This for feature array.
(index_*): Renamed to ...
(index_cpu_*): This for cpu array.
[__ASSEMBLER__] (HAS_FEATURE): Add and use field.
[__ASSEMBLER__] (HAS_CPU_FEATURE)): Pass cpu to HAS_FEATURE.
[__ASSEMBLER__] (HAS_ARCH_FEATURE)): Pass arch to HAS_FEATURE.
[!__ASSEMBLER__] (HAS_CPU_FEATURE): Replace index_##name and
bit_##name with index_cpu_##name and bit_cpu_##name.
[!__ASSEMBLER__] (HAS_ARCH_FEATURE): Replace index_##name and
bit_##name with index_arch_##name and bit_arch_##name.
We should turn on bit_Prefer_MAP_32BIT_EXEC in EXTRA_LD_ENVVARS without
overriding other bits.
[BZ #19758]
* sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
(EXTRA_LD_ENVVARS): Or bit_Prefer_MAP_32BIT_EXEC.
According to Silvermont software optimization guide, for 64-bit
applications, branch prediction performance can be negatively impacted
when the target of a branch is more than 4GB away from the branch. Add
the Prefer_MAP_32BIT_EXEC bit so that mmap will try to map executable
pages with MAP_32BIT first. NB: MAP_32BIT will map to lower 2GB, not
lower 4GB, address. Prefer_MAP_32BIT_EXEC reduces bits available for
address space layout randomization (ASLR), which is always disabled for
SUID programs and can only be enabled by setting environment variable,
LD_PREFER_MAP_32BIT_EXEC.
On Fedora 23, this patch speeds up GCC 5 testsuite by 3% on Silvermont.
[BZ #19367]
* sysdeps/unix/sysv/linux/wordsize-64/mmap.c: New file.
* sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/mmap.c: Likewise.
* sysdeps/x86/cpu-features.h (bit_Prefer_MAP_32BIT_EXEC): New.
(index_Prefer_MAP_32BIT_EXEC): Likewise.
