From f5967101e9de12addcda4510dfbac66d7c5779c3 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 30 May 2016 12:56:27 +0200 Subject: 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 Signed-off-by: Borislav Petkov Acked-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar --- arch/x86/lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/lib/Makefile') diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 72a576752a7e..ec969cc3eb20 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -25,7 +25,7 @@ lib-y += memcpy_$(BITS).o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o -obj-y += msr.o msr-reg.o msr-reg-export.o +obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o ifeq ($(CONFIG_X86_32),y) obj-y += atomic64_32.o -- cgit v1.2.3