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[209.132.180.67]) by mx.google.com with ESMTP id j15-v6si9457502pgg.433.2018.10.05.19.57.41; Fri, 05 Oct 2018 19:57:41 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@zx2c4.com header.s=mail header.b="ICe56U/u"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=zx2c4.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729474AbeJFJ7I (ORCPT + 32 others); Sat, 6 Oct 2018 05:59:08 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:50073 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726812AbeJFJ7H (ORCPT ); Sat, 6 Oct 2018 05:59:07 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 58f33857; Sat, 6 Oct 2018 02:57:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; s=mail; bh=eI1BXc22Lh2xCEMoFQc7iWy7E mM=; b=ICe56U/uVD5WO7XB1z25zmXPd7BVHBnnzjTu1fqdNl5LEbTjHWbmWCDkM aLVad8Vuq0LIjb84MjE53Pcpr/ueFrz9RsXRSAtwuwANFFsbzOGvWciAEDq5KLbI vpXj+o+/FnDf9pOQHpJTkd1X/LZ822/nJmM3UMZ24+Eui1n0ndg50nL/UhVYIcLM HrTarqmZxRJpTyFLcfCM5o7aCM23d+Hv9gigQqJtJSPBzGHZ48Ls+YtS0IuJPILD JffpN2IHSrUlAC4XcQQKNYx2JcrTJwCx39fkvchFYbGo2ljo2y/wONGQ1KC3S9hc aZHIPHgNf2H2LWgkDTUMefKFWMYhQ== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 045e05f3 (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Sat, 6 Oct 2018 02:57:03 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net, gregkh@linuxfoundation.org Cc: "Jason A. Donenfeld" , Samuel Neves , Andy Lutomirski , Thomas Gleixner , linux-arch@vger.kernel.org Subject: [PATCH net-next v7 02/28] asm: simd context helper API Date: Sat, 6 Oct 2018 04:56:43 +0200 Message-Id: <20181006025709.4019-3-Jason@zx2c4.com> In-Reply-To: <20181006025709.4019-1-Jason@zx2c4.com> References: <20181006025709.4019-1-Jason@zx2c4.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sometimes it's useful to amortize calls to XSAVE/XRSTOR and the related FPU/SIMD functions over a number of calls, because FPU restoration is quite expensive. This adds a simple header for carrying out this pattern: simd_context_t simd_context; simd_get(&simd_context); while ((item = get_item_from_queue()) != NULL) { encrypt_item(item, &simd_context); simd_relax(&simd_context); } simd_put(&simd_context); The relaxation step ensures that we don't trample over preemption, and the get/put API should be a familiar paradigm in the kernel. On the other end, code that actually wants to use SIMD instructions can accept this as a parameter and check it via: void encrypt_item(struct item *item, simd_context_t *simd_context) { if (item->len > LARGE_FOR_SIMD && simd_use(simd_context)) wild_simd_code(item); else boring_scalar_code(item); } The actual XSAVE happens during simd_use (and only on the first time), so that if the context is never actually used, no performance penalty is hit. Signed-off-by: Jason A. Donenfeld Cc: Samuel Neves Cc: Andy Lutomirski Cc: Thomas Gleixner Cc: Greg KH Cc: linux-arch@vger.kernel.org --- arch/alpha/include/asm/Kbuild | 1 + arch/arc/include/asm/Kbuild | 1 + arch/arm/include/asm/Kbuild | 1 - arch/arm/include/asm/simd.h | 63 ++++++++++++++++++++++++++++++ arch/arm64/include/asm/simd.h | 51 +++++++++++++++++++++--- arch/c6x/include/asm/Kbuild | 1 + arch/h8300/include/asm/Kbuild | 1 + arch/hexagon/include/asm/Kbuild | 1 + arch/ia64/include/asm/Kbuild | 1 + arch/m68k/include/asm/Kbuild | 1 + arch/microblaze/include/asm/Kbuild | 1 + arch/mips/include/asm/Kbuild | 1 + arch/nds32/include/asm/Kbuild | 1 + arch/nios2/include/asm/Kbuild | 1 + arch/openrisc/include/asm/Kbuild | 1 + arch/parisc/include/asm/Kbuild | 1 + arch/powerpc/include/asm/Kbuild | 1 + arch/riscv/include/asm/Kbuild | 1 + arch/s390/include/asm/Kbuild | 1 + arch/sh/include/asm/Kbuild | 1 + arch/sparc/include/asm/Kbuild | 1 + arch/um/include/asm/Kbuild | 1 + arch/unicore32/include/asm/Kbuild | 1 + arch/x86/include/asm/simd.h | 44 ++++++++++++++++++++- arch/xtensa/include/asm/Kbuild | 1 + include/asm-generic/simd.h | 20 ++++++++++ include/linux/simd.h | 32 +++++++++++++++ 27 files changed, 224 insertions(+), 8 deletions(-) create mode 100644 arch/arm/include/asm/simd.h create mode 100644 include/linux/simd.h -- 2.19.0 diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild index 0580cb8c84b2..220dfd170d45 100644 --- a/arch/alpha/include/asm/Kbuild +++ b/arch/alpha/include/asm/Kbuild @@ -13,3 +13,4 @@ generic-y += sections.h generic-y += trace_clock.h generic-y += current.h generic-y += kprobes.h +generic-y += simd.h diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index feed50ce89fa..a7f4255f1649 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -22,6 +22,7 @@ generic-y += parport.h generic-y += pci.h generic-y += percpu.h generic-y += preempt.h +generic-y += simd.h generic-y += topology.h generic-y += trace_clock.h generic-y += user.h diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index 1d66db9c9db5..ebdc9eeb8d39 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -16,7 +16,6 @@ generic-y += rwsem.h generic-y += seccomp.h generic-y += segment.h generic-y += serial.h -generic-y += simd.h generic-y += sizes.h generic-y += timex.h generic-y += trace_clock.h diff --git a/arch/arm/include/asm/simd.h b/arch/arm/include/asm/simd.h new file mode 100644 index 000000000000..264ed84b41d8 --- /dev/null +++ b/arch/arm/include/asm/simd.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld . All Rights Reserved. + */ + +#include +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + +#ifdef CONFIG_KERNEL_MODE_NEON +#include + +static __must_check inline bool may_use_simd(void) +{ + return !in_nmi() && !in_irq() && !in_serving_softirq(); +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ + if (*ctx & HAVE_SIMD_IN_USE) + kernel_neon_end(); + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + kernel_neon_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +} + +#else + +static __must_check inline bool may_use_simd(void) +{ + return false; +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + return false; +} +#endif + +#endif /* _ASM_SIMD_H */ diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h index 6495cc51246f..a45ff1600040 100644 --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -1,11 +1,10 @@ -/* - * Copyright (C) 2017 Linaro Ltd. +/* SPDX-License-Identifier: GPL-2.0 * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published - * by the Free Software Foundation. + * Copyright (C) 2017 Linaro Ltd. + * Copyright (C) 2015-2018 Jason A. Donenfeld . All Rights Reserved. */ +#include #ifndef __ASM_SIMD_H #define __ASM_SIMD_H @@ -16,6 +15,8 @@ #include #ifdef CONFIG_KERNEL_MODE_NEON +#include +#include DECLARE_PER_CPU(bool, kernel_neon_busy); @@ -40,9 +41,47 @@ static __must_check inline bool may_use_simd(void) !this_cpu_read(kernel_neon_busy); } +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ + if (*ctx & HAVE_SIMD_IN_USE) + kernel_neon_end(); + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + kernel_neon_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +} + #else /* ! CONFIG_KERNEL_MODE_NEON */ -static __must_check inline bool may_use_simd(void) { +static __must_check inline bool may_use_simd(void) +{ + return false; +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ return false; } diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild index 33a2c94fed0d..7543c38f7ade 100644 --- a/arch/c6x/include/asm/Kbuild +++ b/arch/c6x/include/asm/Kbuild @@ -30,6 +30,7 @@ generic-y += pgalloc.h generic-y += preempt.h generic-y += segment.h generic-y += serial.h +generic-y += simd.h generic-y += tlbflush.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild index a5d0b2991f47..1fcef25ee19d 100644 --- a/arch/h8300/include/asm/Kbuild +++ b/arch/h8300/include/asm/Kbuild @@ -39,6 +39,7 @@ generic-y += preempt.h generic-y += scatterlist.h generic-y += sections.h generic-y += serial.h +generic-y += simd.h generic-y += sizes.h generic-y += spinlock.h generic-y += timex.h diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild index dd2fd9c0d292..217d4695fd8a 100644 --- a/arch/hexagon/include/asm/Kbuild +++ b/arch/hexagon/include/asm/Kbuild @@ -29,6 +29,7 @@ generic-y += rwsem.h generic-y += sections.h generic-y += segment.h generic-y += serial.h +generic-y += simd.h generic-y += sizes.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild index 557bbc8ba9f5..41c5ebdf79e5 100644 --- a/arch/ia64/include/asm/Kbuild +++ b/arch/ia64/include/asm/Kbuild @@ -4,6 +4,7 @@ generic-y += irq_work.h generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += preempt.h +generic-y += simd.h generic-y += trace_clock.h generic-y += vtime.h generic-y += word-at-a-time.h diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild index a4b8d3331a9e..73898dd1a4d0 100644 --- a/arch/m68k/include/asm/Kbuild +++ b/arch/m68k/include/asm/Kbuild @@ -19,6 +19,7 @@ generic-y += mm-arch-hooks.h generic-y += percpu.h generic-y += preempt.h generic-y += sections.h +generic-y += simd.h generic-y += spinlock.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild index 569ba9e670c1..7a877eea99d3 100644 --- a/arch/microblaze/include/asm/Kbuild +++ b/arch/microblaze/include/asm/Kbuild @@ -25,6 +25,7 @@ generic-y += parport.h generic-y += percpu.h generic-y += preempt.h generic-y += serial.h +generic-y += simd.h generic-y += syscalls.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild index 58351e48421e..e8868e0fb2c3 100644 --- a/arch/mips/include/asm/Kbuild +++ b/arch/mips/include/asm/Kbuild @@ -16,6 +16,7 @@ generic-y += qrwlock.h generic-y += qspinlock.h generic-y += sections.h generic-y += segment.h +generic-y += simd.h generic-y += trace_clock.h generic-y += unaligned.h generic-y += user.h diff --git a/arch/nds32/include/asm/Kbuild b/arch/nds32/include/asm/Kbuild index dbc4e5422550..fb2f113716ce 100644 --- a/arch/nds32/include/asm/Kbuild +++ b/arch/nds32/include/asm/Kbuild @@ -46,6 +46,7 @@ generic-y += sections.h generic-y += segment.h generic-y += serial.h generic-y += shmbuf.h +generic-y += simd.h generic-y += sizes.h generic-y += stat.h generic-y += switch_to.h diff --git a/arch/nios2/include/asm/Kbuild b/arch/nios2/include/asm/Kbuild index 8fde4fa2c34f..571a9d9ad107 100644 --- a/arch/nios2/include/asm/Kbuild +++ b/arch/nios2/include/asm/Kbuild @@ -33,6 +33,7 @@ generic-y += preempt.h generic-y += sections.h generic-y += segment.h generic-y += serial.h +generic-y += simd.h generic-y += spinlock.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild index eb87cd8327c8..b6231211bbad 100644 --- a/arch/openrisc/include/asm/Kbuild +++ b/arch/openrisc/include/asm/Kbuild @@ -34,6 +34,7 @@ generic-y += qrwlock_types.h generic-y += qrwlock.h generic-y += sections.h generic-y += segment.h +generic-y += simd.h generic-y += string.h generic-y += switch_to.h generic-y += topology.h diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild index 2013d639e735..97970b4d05ab 100644 --- a/arch/parisc/include/asm/Kbuild +++ b/arch/parisc/include/asm/Kbuild @@ -17,6 +17,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += seccomp.h generic-y += segment.h +generic-y += simd.h generic-y += topology.h generic-y += trace_clock.h generic-y += user.h diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index 3196d227e351..2337190aaf69 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -8,3 +8,4 @@ generic-y += preempt.h generic-y += rwsem.h generic-y += vtime.h generic-y += msi.h +generic-y += simd.h diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild index efdbe311e936..438a11d9c47a 100644 --- a/arch/riscv/include/asm/Kbuild +++ b/arch/riscv/include/asm/Kbuild @@ -46,6 +46,7 @@ generic-y += setup.h generic-y += shmbuf.h generic-y += shmparam.h generic-y += signal.h +generic-y += simd.h generic-y += socket.h generic-y += sockios.h generic-y += stat.h diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index e3239772887a..3744c4c61fb5 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -22,6 +22,7 @@ generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += rwsem.h +generic-y += simd.h generic-y += trace_clock.h generic-y += unaligned.h generic-y += word-at-a-time.h diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild index 6a5609a55965..8e64ff35a933 100644 --- a/arch/sh/include/asm/Kbuild +++ b/arch/sh/include/asm/Kbuild @@ -16,6 +16,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += rwsem.h generic-y += serial.h +generic-y += simd.h generic-y += sizes.h generic-y += trace_clock.h generic-y += xor.h diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild index 410b263ef5c8..72b9e08fb350 100644 --- a/arch/sparc/include/asm/Kbuild +++ b/arch/sparc/include/asm/Kbuild @@ -17,5 +17,6 @@ generic-y += msi.h generic-y += preempt.h generic-y += rwsem.h generic-y += serial.h +generic-y += simd.h generic-y += trace_clock.h generic-y += word-at-a-time.h diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index b10dde6cb793..8c2bfa6e0494 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -22,6 +22,7 @@ generic-y += param.h generic-y += pci.h generic-y += percpu.h generic-y += preempt.h +generic-y += simd.h generic-y += switch_to.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild index bfc7abe77905..98a908720bbd 100644 --- a/arch/unicore32/include/asm/Kbuild +++ b/arch/unicore32/include/asm/Kbuild @@ -27,6 +27,7 @@ generic-y += preempt.h generic-y += sections.h generic-y += segment.h generic-y += serial.h +generic-y += simd.h generic-y += sizes.h generic-y += syscalls.h generic-y += topology.h diff --git a/arch/x86/include/asm/simd.h b/arch/x86/include/asm/simd.h index a341c878e977..4aad7f158dcb 100644 --- a/arch/x86/include/asm/simd.h +++ b/arch/x86/include/asm/simd.h @@ -1,4 +1,11 @@ -/* SPDX-License-Identifier: GPL-2.0 */ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld . All Rights Reserved. + */ + +#include +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H #include @@ -10,3 +17,38 @@ static __must_check inline bool may_use_simd(void) { return irq_fpu_usable(); } + +static inline void simd_get(simd_context_t *ctx) +{ +#if !defined(CONFIG_UML) + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +#else + *ctx = HAVE_NO_SIMD; +#endif +} + +static inline void simd_put(simd_context_t *ctx) +{ +#if !defined(CONFIG_UML) + if (*ctx & HAVE_SIMD_IN_USE) + kernel_fpu_end(); +#endif + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ +#if !defined(CONFIG_UML) + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + kernel_fpu_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +#else + return false; +#endif +} + +#endif /* _ASM_SIMD_H */ diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index 82c756431b49..7950f359649d 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -24,6 +24,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += rwsem.h generic-y += sections.h +generic-y += simd.h generic-y += topology.h generic-y += trace_clock.h generic-y += word-at-a-time.h diff --git a/include/asm-generic/simd.h b/include/asm-generic/simd.h index d0343d58a74a..b3dd61ac010e 100644 --- a/include/asm-generic/simd.h +++ b/include/asm-generic/simd.h @@ -1,5 +1,9 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#include +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + #include /* @@ -13,3 +17,19 @@ static __must_check inline bool may_use_simd(void) { return !in_interrupt(); } + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + return false; +} + +#endif /* _ASM_SIMD_H */ diff --git a/include/linux/simd.h b/include/linux/simd.h new file mode 100644 index 000000000000..4e0b8a9bdc14 --- /dev/null +++ b/include/linux/simd.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld . All Rights Reserved. + */ + +#ifndef _SIMD_H +#define _SIMD_H + +typedef enum { + HAVE_NO_SIMD = 1 << 0, + HAVE_FULL_SIMD = 1 << 1, + HAVE_SIMD_IN_USE = 1 << 31 +} simd_context_t; + +#define DONT_USE_SIMD ((simd_context_t []){ HAVE_NO_SIMD }) + +#include +#include + +static inline bool simd_relax(simd_context_t *ctx) +{ +#ifdef CONFIG_PREEMPT + if ((*ctx & HAVE_SIMD_IN_USE) && need_resched()) { + simd_put(ctx); + simd_get(ctx); + return true; + } +#endif + return false; +} + +#endif /* _SIMD_H */