diff options
| 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 /arch/x86/Kconfig | |
| parent | 08dd8cd06ed95625b9e2fac43c78fcb45b7eaf94 (diff) | |
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 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0a7b885964ba..729d41d9ced3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -294,11 +294,6 @@ config X86_32_LAZY_GS def_bool y depends on X86_32 && !CC_STACKPROTECTOR -config ARCH_HWEIGHT_CFLAGS - string - default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 - default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 - config ARCH_SUPPORTS_UPROBES def_bool y |