Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752342AbdLGWmI (ORCPT ); Thu, 7 Dec 2017 17:42:08 -0500 Received: from mail-wr0-f195.google.com ([209.85.128.195]:40248 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750978AbdLGWmF (ORCPT ); Thu, 7 Dec 2017 17:42:05 -0500 X-Google-Smtp-Source: AGs4zMbkXj5mDvcQv0yxyU6ODtsTmJxJreH1BCVVLiPi0jgyXH0k3PekumJz+DkDg9gFkgcXHuWucw== From: Alexey Dobriyan To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, Alexey Dobriyan Subject: [PATCH 2/5] -march=native: POPCNT support Date: Fri, 8 Dec 2017 01:41:51 +0300 Message-Id: <20171207224154.4687-2-adobriyan@gmail.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20171207224154.4687-1-adobriyan@gmail.com> References: <20171207224154.4687-1-adobriyan@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5276 Lines: 178 Mainline kernel can only generate "popcnt rax, rdi" instruction with alternative masquareading as function call. Patch allows to generate all POPCNT variations and inlines hweigth*() family of functions. $ objdump -dr ../obj/vmlinux | grep popcnt ffffffff81004f6d: f3 48 0f b8 c9 popcnt rcx,rcx ffffffff81008484: f3 48 0f b8 03 popcnt rax,QWORD PTR [rbx] ffffffff81073aae: f3 48 0f b8 d8 popcnt rbx,rax ... Signed-off-by: Alexey Dobriyan --- arch/x86/include/asm/arch_hweight.h | 32 ++++++++++++++++++++++++++++++-- arch/x86/lib/Makefile | 5 ++++- include/linux/bitops.h | 2 ++ lib/Makefile | 2 ++ scripts/kconfig/cpuid.c | 6 ++++++ scripts/march-native.sh | 6 +++++- 6 files changed, 49 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h index 34a10b2d5b73..58e4f65d8665 100644 --- a/arch/x86/include/asm/arch_hweight.h +++ b/arch/x86/include/asm/arch_hweight.h @@ -2,6 +2,34 @@ #ifndef _ASM_X86_HWEIGHT_H #define _ASM_X86_HWEIGHT_H +#define __HAVE_ARCH_SW_HWEIGHT + +#ifdef CONFIG_MARCH_NATIVE_POPCNT +static inline unsigned int __arch_hweight64(uint64_t x) +{ + uint64_t rv; + asm ("popcnt %1, %0" : "=r" (rv) : "rm" (x)); + return rv; +} + +static inline unsigned int __arch_hweight32(uint32_t x) +{ + uint32_t rv; + asm ("popcnt %1, %0" : "=r" (rv) : "rm" (x)); + return rv; +} + +static inline unsigned int __arch_hweight16(uint16_t x) +{ + return __arch_hweight32(x); +} + +static inline unsigned int __arch_hweight8(uint8_t x) +{ + return __arch_hweight32(x); +} +#else + #include #ifdef CONFIG_64BIT @@ -18,8 +46,6 @@ #define REG_OUT "a" #endif -#define __HAVE_ARCH_SW_HWEIGHT - static __always_inline unsigned int __arch_hweight32(unsigned int w) { unsigned int res; @@ -61,3 +87,5 @@ static __always_inline unsigned long __arch_hweight64(__u64 w) #endif /* CONFIG_X86_32 */ #endif + +#endif diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 7b181b61170e..c26ad76e7048 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -27,7 +27,10 @@ lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o -obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o +obj-y += msr.o msr-reg.o msr-reg-export.o +ifneq ($(CONFIG_MARCH_NATIVE),y) + obj-y += hweight.o +endif ifeq ($(CONFIG_X86_32),y) obj-y += atomic64_32.o diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 4cac4e1a72ff..ab58fed4ab90 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -26,10 +26,12 @@ (((~0ULL) - (1ULL << (l)) + 1) & \ (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) +#ifndef CONFIG_MARCH_NATIVE_POPCNT extern unsigned int __sw_hweight8(unsigned int w); extern unsigned int __sw_hweight16(unsigned int w); extern unsigned int __sw_hweight32(unsigned int w); extern unsigned long __sw_hweight64(__u64 w); +#endif /* * Include this here because some architectures need generic_ffs/fls in diff --git a/lib/Makefile b/lib/Makefile index d11c48ec8ffd..3867b73721aa 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -81,7 +81,9 @@ obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o +ifneq ($(CONFIG_MARCH_NATIVE_POPCNT),y) obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o +endif obj-$(CONFIG_BTREE) += btree.o obj-$(CONFIG_INTERVAL_TREE) += interval_tree.o diff --git a/scripts/kconfig/cpuid.c b/scripts/kconfig/cpuid.c index f1983027fe2b..e565dd446bdf 100644 --- a/scripts/kconfig/cpuid.c +++ b/scripts/kconfig/cpuid.c @@ -42,6 +42,8 @@ static inline void cpuid2(uint32_t eax0, uint32_t ecx0, uint32_t *eax, uint32_t ); } +static bool popcnt = false; + static uint32_t eax0_max; static void intel(void) @@ -51,6 +53,9 @@ static void intel(void) if (eax0_max >= 1) { cpuid(1, &eax, &ecx, &edx, &ebx); // printf("%08x %08x %08x %08x\n", eax, ecx, edx, ebx); + + if (ecx & (1 << 23)) + popcnt = true; } } @@ -70,6 +75,7 @@ int main(int argc, char *argv[]) intel(); #define _(x) if (streq(opt, #x)) return x ? EXIT_SUCCESS : EXIT_FAILURE + _(popcnt); #undef _ return EXIT_FAILURE; diff --git a/scripts/march-native.sh b/scripts/march-native.sh index 4f0fc82f7722..6641e356b646 100755 --- a/scripts/march-native.sh +++ b/scripts/march-native.sh @@ -29,6 +29,10 @@ option() { echo "#define $1 1" >>"$AUTOCONF2" } +if test -x "$CPUID"; then + "$CPUID" popcnt && option "CONFIG_MARCH_NATIVE_POPCNT" +fi + if test ! -f "$AUTOCONF1" -o ! -f "$AUTOCONF2"; then exit 0 fi @@ -72,7 +76,7 @@ for i in $COLLECT_GCC_OPTIONS; do -mmmx) option "CONFIG_MARCH_NATIVE_MMX" ;; -mmovbe) option "CONFIG_MARCH_NATIVE_MOVBE" ;; -mpclmul) option "CONFIG_MARCH_NATIVE_PCLMUL" ;; - -mpopcnt) option "CONFIG_MATCH_NATIVE_POPCNT" ;; + -mpopcnt);; -mprfchw) option "CONFIG_MARCH_NATIVE_PREFETCHW" ;; -mrdrnd) option "CONFIG_MARCH_NATIVE_RDRND" ;; -mrdseed) option "CONFIG_MARCH_NATIVE_RDSEED" ;; -- 2.13.6