util/bufferiszero: Split out host include files

Message ID	20240606051441.111975-1-richard.henderson@linaro.org (mailing list archive)
State	New
Headers	show Return-Path: <qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org> From: Richard Henderson <richard.henderson@linaro.org> To: qemu-devel@nongnu.org Cc: maobibo@loongson.cn Subject: [PATCH] util/bufferiszero: Split out host include files Date: Wed, 5 Jun 2024 22:14:41 -0700 Message-Id: <20240606051441.111975-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::530; envelope-from=richard.henderson@linaro.org; helo=mail-pg1-x530.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action Precedence: list Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org
Series	util/bufferiszero: Split out host include files \| expand util/bufferiszero: Split out host include files

diff --git a/host/include/aarch64/host/bufferiszero.h.inc b/host/include/aarch64/host/bufferiszero.h.inc new file mode 100644 index 0000000000..0f0e478831 --- /dev/null +++ b/host/include/aarch64/host/bufferiszero.h.inc @@ -0,0 +1,76 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * buffer_is_zero acceleration, aarch64 version. + */ + +#ifdef __ARM_NEON +#include <arm_neon.h> + +/* + * Helper for preventing the compiler from reassociating + * chains of binary vector operations. + */ +#define REASSOC_BARRIER(vec0, vec1) asm("" : "+w"(vec0), "+w"(vec1)) + +static bool buffer_is_zero_simd(const void *buf, size_t len) +{ + uint32x4_t t0, t1, t2, t3; + + /* Align head/tail to 16-byte boundaries. */ + const uint32x4_t *p = QEMU_ALIGN_PTR_DOWN(buf + 16, 16); + const uint32x4_t *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 16); + + /* Unaligned loads at head/tail. */ + t0 = vld1q_u32(buf) | vld1q_u32(buf + len - 16); + + /* Collect a partial block at tail end. */ + t1 = e[-7] | e[-6]; + t2 = e[-5] | e[-4]; + t3 = e[-3] | e[-2]; + t0 |= e[-1]; + REASSOC_BARRIER(t0, t1); + REASSOC_BARRIER(t2, t3); + t0 |= t1; + t2 |= t3; + REASSOC_BARRIER(t0, t2); + t0 |= t2; + + /* + * Loop over complete 128-byte blocks. + * With the head and tail removed, e - p >= 14, so the loop + * must iterate at least once. + */ + do { + /* + * Reduce via UMAXV. Whatever the actual result, + * it will only be zero if all input bytes are zero. + */ + if (unlikely(vmaxvq_u32(t0) != 0)) { + return false; + } + + t0 = p[0] | p[1]; + t1 = p[2] | p[3]; + t2 = p[4] | p[5]; + t3 = p[6] | p[7]; + REASSOC_BARRIER(t0, t1); + REASSOC_BARRIER(t2, t3); + t0 |= t1; + t2 |= t3; + REASSOC_BARRIER(t0, t2); + t0 |= t2; + p += 8; + } while (p < e - 7); + + return vmaxvq_u32(t0) == 0; +} + +static biz_accel_fn const accel_table[] = { + buffer_is_zero_int_ge256, + buffer_is_zero_simd, +}; + +#define best_accel() 1 +#else +# include "host/include/generic/host/bufferiszero.h.inc" +#endif diff --git a/host/include/generic/host/bufferiszero.h.inc b/host/include/generic/host/bufferiszero.h.inc new file mode 100644 index 0000000000..ea0875c24a --- /dev/null +++ b/host/include/generic/host/bufferiszero.h.inc @@ -0,0 +1,10 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * buffer_is_zero acceleration, generic version. + */ + +static biz_accel_fn const accel_table[1] = { + buffer_is_zero_int_ge256 +}; + +#define best_accel() 0 diff --git a/host/include/i386/host/bufferiszero.h.inc b/host/include/i386/host/bufferiszero.h.inc new file mode 100644 index 0000000000..ac9bcd07ee --- /dev/null +++ b/host/include/i386/host/bufferiszero.h.inc @@ -0,0 +1,124 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * buffer_is_zero acceleration, x86 version. + */ + +#if defined(CONFIG_AVX2_OPT) || defined(__SSE2__) +#include <immintrin.h> + +/* Helper for preventing the compiler from reassociating + chains of binary vector operations. */ +#define SSE_REASSOC_BARRIER(vec0, vec1) asm("" : "+x"(vec0), "+x"(vec1)) + +/* Note that these vectorized functions may assume len >= 256. */ + +static bool __attribute__((target("sse2"))) +buffer_zero_sse2(const void *buf, size_t len) +{ + /* Unaligned loads at head/tail. */ + __m128i v = *(__m128i_u *)(buf); + __m128i w = *(__m128i_u *)(buf + len - 16); + /* Align head/tail to 16-byte boundaries. */ + const __m128i *p = QEMU_ALIGN_PTR_DOWN(buf + 16, 16); + const __m128i *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 16); + __m128i zero = { 0 }; + + /* Collect a partial block at tail end. */ + v |= e[-1]; w |= e[-2]; + SSE_REASSOC_BARRIER(v, w); + v |= e[-3]; w |= e[-4]; + SSE_REASSOC_BARRIER(v, w); + v |= e[-5]; w |= e[-6]; + SSE_REASSOC_BARRIER(v, w); + v |= e[-7]; v |= w; + + /* + * Loop over complete 128-byte blocks. + * With the head and tail removed, e - p >= 14, so the loop + * must iterate at least once. + */ + do { + v = _mm_cmpeq_epi8(v, zero); + if (unlikely(_mm_movemask_epi8(v) != 0xFFFF)) { + return false; + } + v = p[0]; w = p[1]; + SSE_REASSOC_BARRIER(v, w); + v |= p[2]; w |= p[3]; + SSE_REASSOC_BARRIER(v, w); + v |= p[4]; w |= p[5]; + SSE_REASSOC_BARRIER(v, w); + v |= p[6]; w |= p[7]; + SSE_REASSOC_BARRIER(v, w); + v |= w; + p += 8; + } while (p < e - 7); + + return _mm_movemask_epi8(_mm_cmpeq_epi8(v, zero)) == 0xFFFF; +} + +#ifdef CONFIG_AVX2_OPT +static bool __attribute__((target("avx2"))) +buffer_zero_avx2(const void *buf, size_t len) +{ + /* Unaligned loads at head/tail. */ + __m256i v = *(__m256i_u *)(buf); + __m256i w = *(__m256i_u *)(buf + len - 32); + /* Align head/tail to 32-byte boundaries. */ + const __m256i *p = QEMU_ALIGN_PTR_DOWN(buf + 32, 32); + const __m256i *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 32); + __m256i zero = { 0 }; + + /* Collect a partial block at tail end. */ + v |= e[-1]; w |= e[-2]; + SSE_REASSOC_BARRIER(v, w); + v |= e[-3]; w |= e[-4]; + SSE_REASSOC_BARRIER(v, w); + v |= e[-5]; w |= e[-6]; + SSE_REASSOC_BARRIER(v, w); + v |= e[-7]; v |= w; + + /* Loop over complete 256-byte blocks. */ + for (; p < e - 7; p += 8) { + /* PTEST is not profitable here. */ + v = _mm256_cmpeq_epi8(v, zero); + if (unlikely(_mm256_movemask_epi8(v) != 0xFFFFFFFF)) { + return false; + } + v = p[0]; w = p[1]; + SSE_REASSOC_BARRIER(v, w); + v |= p[2]; w |= p[3]; + SSE_REASSOC_BARRIER(v, w); + v |= p[4]; w |= p[5]; + SSE_REASSOC_BARRIER(v, w); + v |= p[6]; w |= p[7]; + SSE_REASSOC_BARRIER(v, w); + v |= w; + } + + return _mm256_movemask_epi8(_mm256_cmpeq_epi8(v, zero)) == 0xFFFFFFFF; +} +#endif /* CONFIG_AVX2_OPT */ + +static biz_accel_fn const accel_table[] = { + buffer_is_zero_int_ge256, + buffer_zero_sse2, +#ifdef CONFIG_AVX2_OPT + buffer_zero_avx2, +#endif +}; + +static unsigned best_accel(void) +{ +#ifdef CONFIG_AVX2_OPT + unsigned info = cpuinfo_init(); + if (info & CPUINFO_AVX2) { + return 2; + } +#endif + return 1; +} + +#else +# include "host/include/generic/host/bufferiszero.h.inc" +#endif diff --git a/host/include/x86_64/host/bufferiszero.h.inc b/host/include/x86_64/host/bufferiszero.h.inc new file mode 100644 index 0000000000..f3893d10eb --- /dev/null +++ b/host/include/x86_64/host/bufferiszero.h.inc @@ -0,0 +1 @@ +#include "host/include/i386/host/bufferiszero.h.inc" diff --git a/util/bufferiszero.c b/util/bufferiszero.c index 11c080e02c..6e178e0105 100644 --- a/util/bufferiszero.c +++ b/util/bufferiszero.c @@ -81,196 +81,7 @@ static bool buffer_is_zero_int_ge256(const void *buf, size_t len) return t == 0; } -#if defined(CONFIG_AVX2_OPT) || defined(__SSE2__) -#include <immintrin.h> - -/* Helper for preventing the compiler from reassociating - chains of binary vector operations. */ -#define SSE_REASSOC_BARRIER(vec0, vec1) asm("" : "+x"(vec0), "+x"(vec1)) - -/* Note that these vectorized functions may assume len >= 256. */ - -static bool __attribute__((target("sse2"))) -buffer_zero_sse2(const void *buf, size_t len) -{ - /* Unaligned loads at head/tail. */ - __m128i v = *(__m128i_u *)(buf); - __m128i w = *(__m128i_u *)(buf + len - 16); - /* Align head/tail to 16-byte boundaries. */ - const __m128i *p = QEMU_ALIGN_PTR_DOWN(buf + 16, 16); - const __m128i *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 16); - __m128i zero = { 0 }; - - /* Collect a partial block at tail end. */ - v |= e[-1]; w |= e[-2]; - SSE_REASSOC_BARRIER(v, w); - v |= e[-3]; w |= e[-4]; - SSE_REASSOC_BARRIER(v, w); - v |= e[-5]; w |= e[-6]; - SSE_REASSOC_BARRIER(v, w); - v |= e[-7]; v |= w; - - /* - * Loop over complete 128-byte blocks. - * With the head and tail removed, e - p >= 14, so the loop - * must iterate at least once. - */ - do { - v = _mm_cmpeq_epi8(v, zero); - if (unlikely(_mm_movemask_epi8(v) != 0xFFFF)) { - return false; - } - v = p[0]; w = p[1]; - SSE_REASSOC_BARRIER(v, w); - v |= p[2]; w |= p[3]; - SSE_REASSOC_BARRIER(v, w); - v |= p[4]; w |= p[5]; - SSE_REASSOC_BARRIER(v, w); - v |= p[6]; w |= p[7]; - SSE_REASSOC_BARRIER(v, w); - v |= w; - p += 8; - } while (p < e - 7); - - return _mm_movemask_epi8(_mm_cmpeq_epi8(v, zero)) == 0xFFFF; -} - -#ifdef CONFIG_AVX2_OPT -static bool __attribute__((target("avx2"))) -buffer_zero_avx2(const void *buf, size_t len) -{ - /* Unaligned loads at head/tail. */ - __m256i v = *(__m256i_u *)(buf); - __m256i w = *(__m256i_u *)(buf + len - 32); - /* Align head/tail to 32-byte boundaries. */ - const __m256i *p = QEMU_ALIGN_PTR_DOWN(buf + 32, 32); - const __m256i *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 32); - __m256i zero = { 0 }; - - /* Collect a partial block at tail end. */ - v |= e[-1]; w |= e[-2]; - SSE_REASSOC_BARRIER(v, w); - v |= e[-3]; w |= e[-4]; - SSE_REASSOC_BARRIER(v, w); - v |= e[-5]; w |= e[-6]; - SSE_REASSOC_BARRIER(v, w); - v |= e[-7]; v |= w; - - /* Loop over complete 256-byte blocks. */ - for (; p < e - 7; p += 8) { - /* PTEST is not profitable here. */ - v = _mm256_cmpeq_epi8(v, zero); - if (unlikely(_mm256_movemask_epi8(v) != 0xFFFFFFFF)) { - return false; - } - v = p[0]; w = p[1]; - SSE_REASSOC_BARRIER(v, w); - v |= p[2]; w |= p[3]; - SSE_REASSOC_BARRIER(v, w); - v |= p[4]; w |= p[5]; - SSE_REASSOC_BARRIER(v, w); - v |= p[6]; w |= p[7]; - SSE_REASSOC_BARRIER(v, w); - v |= w; - } - - return _mm256_movemask_epi8(_mm256_cmpeq_epi8(v, zero)) == 0xFFFFFFFF; -} -#endif /* CONFIG_AVX2_OPT */ - -static biz_accel_fn const accel_table[] = { - buffer_is_zero_int_ge256, - buffer_zero_sse2, -#ifdef CONFIG_AVX2_OPT - buffer_zero_avx2, -#endif -}; - -static unsigned best_accel(void) -{ -#ifdef CONFIG_AVX2_OPT - unsigned info = cpuinfo_init(); - - if (info & CPUINFO_AVX2) { - return 2; - } -#endif - return 1; -} - -#elif defined(__aarch64__) && defined(__ARM_NEON) -#include <arm_neon.h> - -/* - * Helper for preventing the compiler from reassociating - * chains of binary vector operations. - */ -#define REASSOC_BARRIER(vec0, vec1) asm("" : "+w"(vec0), "+w"(vec1)) - -static bool buffer_is_zero_simd(const void *buf, size_t len) -{ - uint32x4_t t0, t1, t2, t3; - - /* Align head/tail to 16-byte boundaries. */ - const uint32x4_t *p = QEMU_ALIGN_PTR_DOWN(buf + 16, 16); - const uint32x4_t *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 16); - - /* Unaligned loads at head/tail. */ - t0 = vld1q_u32(buf) | vld1q_u32(buf + len - 16); - - /* Collect a partial block at tail end. */ - t1 = e[-7] | e[-6]; - t2 = e[-5] | e[-4]; - t3 = e[-3] | e[-2]; - t0 |= e[-1]; - REASSOC_BARRIER(t0, t1); - REASSOC_BARRIER(t2, t3); - t0 |= t1; - t2 |= t3; - REASSOC_BARRIER(t0, t2); - t0 |= t2; - - /* - * Loop over complete 128-byte blocks. - * With the head and tail removed, e - p >= 14, so the loop - * must iterate at least once. - */ - do { - /* - * Reduce via UMAXV. Whatever the actual result, - * it will only be zero if all input bytes are zero. - */ - if (unlikely(vmaxvq_u32(t0) != 0)) { - return false; - } - - t0 = p[0] | p[1]; - t1 = p[2] | p[3]; - t2 = p[4] | p[5]; - t3 = p[6] | p[7]; - REASSOC_BARRIER(t0, t1); - REASSOC_BARRIER(t2, t3); - t0 |= t1; - t2 |= t3; - REASSOC_BARRIER(t0, t2); - t0 |= t2; - p += 8; - } while (p < e - 7); - - return vmaxvq_u32(t0) == 0; -} - -#define best_accel() 1 -static biz_accel_fn const accel_table[] = { - buffer_is_zero_int_ge256, - buffer_is_zero_simd, -}; -#else -#define best_accel() 0 -static biz_accel_fn const accel_table[1] = { - buffer_is_zero_int_ge256 -}; -#endif +#include "host/bufferiszero.h.inc" static biz_accel_fn buffer_is_zero_accel; static unsigned accel_index;

util/bufferiszero: Split out host include files

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