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| author | Borislav Petkov <bp@suse.de> | 2016-05-30 12:56:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-08 15:01:02 +0200 |
| commit | f5967101e9de12addcda4510dfbac66d7c5779c3 (patch) | |
| tree | 2f01f9e5eb430728ebecd5abff9851fafb5c8c62 /lib/Makefile | |
| parent | 08dd8cd06ed95625b9e2fac43c78fcb45b7eaf94 (diff) | |
| download | linux-f5967101e9de12addcda4510dfbac66d7c5779c3.tar.bz2 | |
x86/hweight: Get rid of the special calling convention
People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench
into kcov, lto, etc, experimentations.
Add asm versions for __sw_hweight{32,64}() and do explicit saving and
restoring of clobbered registers. This gets rid of the special calling
convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs.
We still need to hardcode POPCNT and register operands as some old gas
versions which we support, do not know about POPCNT.
Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives
can do padding now.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/Makefile')
| -rw-r--r-- | lib/Makefile | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/lib/Makefile b/lib/Makefile index ff6a7a6c6395..07d06a8b9788 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -15,9 +15,6 @@ KCOV_INSTRUMENT_rbtree.o := n KCOV_INSTRUMENT_list_debug.o := n KCOV_INSTRUMENT_debugobjects.o := n KCOV_INSTRUMENT_dynamic_debug.o := n -# Kernel does not boot if we instrument this file as it uses custom calling -# convention (see CONFIG_ARCH_HWEIGHT_CFLAGS). -KCOV_INSTRUMENT_hweight.o := n lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o timerqueue.o\ @@ -74,8 +71,6 @@ obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o -GCOV_PROFILE_hweight.o := n -CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS)) obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o obj-$(CONFIG_BTREE) += btree.o |