cutils: Move buffer_is_zero and subroutines to a new file
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-2-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/util/Makefile.objs b/util/Makefile.objs
index 96cb1e0..ffca8f3 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -1,4 +1,5 @@
util-obj-y = osdep.o cutils.o unicode.o qemu-timer-common.o
+util-obj-y += bufferiszero.o
util-obj-$(CONFIG_POSIX) += compatfd.o
util-obj-$(CONFIG_POSIX) += event_notifier-posix.o
util-obj-$(CONFIG_POSIX) += mmap-alloc.o
diff --git a/util/bufferiszero.c b/util/bufferiszero.c
new file mode 100644
index 0000000..9bb1ae5
--- /dev/null
+++ b/util/bufferiszero.c
@@ -0,0 +1,272 @@
+/*
+ * Simple C functions to supplement the C library
+ *
+ * Copyright (c) 2006 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/cutils.h"
+
+
+/* vector definitions */
+#ifdef __ALTIVEC__
+#include <altivec.h>
+/* The altivec.h header says we're allowed to undef these for
+ * C++ compatibility. Here we don't care about C++, but we
+ * undef them anyway to avoid namespace pollution.
+ */
+#undef vector
+#undef pixel
+#undef bool
+#define VECTYPE __vector unsigned char
+#define SPLAT(p) vec_splat(vec_ld(0, p), 0)
+#define ALL_EQ(v1, v2) vec_all_eq(v1, v2)
+#define VEC_OR(v1, v2) ((v1) | (v2))
+/* altivec.h may redefine the bool macro as vector type.
+ * Reset it to POSIX semantics. */
+#define bool _Bool
+#elif defined __SSE2__
+#include <emmintrin.h>
+#define VECTYPE __m128i
+#define SPLAT(p) _mm_set1_epi8(*(p))
+#define ALL_EQ(v1, v2) (_mm_movemask_epi8(_mm_cmpeq_epi8(v1, v2)) == 0xFFFF)
+#define VEC_OR(v1, v2) (_mm_or_si128(v1, v2))
+#elif defined(__aarch64__)
+#include "arm_neon.h"
+#define VECTYPE uint64x2_t
+#define ALL_EQ(v1, v2) \
+ ((vgetq_lane_u64(v1, 0) == vgetq_lane_u64(v2, 0)) && \
+ (vgetq_lane_u64(v1, 1) == vgetq_lane_u64(v2, 1)))
+#define VEC_OR(v1, v2) ((v1) | (v2))
+#else
+#define VECTYPE unsigned long
+#define SPLAT(p) (*(p) * (~0UL / 255))
+#define ALL_EQ(v1, v2) ((v1) == (v2))
+#define VEC_OR(v1, v2) ((v1) | (v2))
+#endif
+
+#define BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR 8
+
+static bool
+can_use_buffer_find_nonzero_offset_inner(const void *buf, size_t len)
+{
+ return (len % (BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR
+ * sizeof(VECTYPE)) == 0
+ && ((uintptr_t) buf) % sizeof(VECTYPE) == 0);
+}
+
+/*
+ * Searches for an area with non-zero content in a buffer
+ *
+ * Attention! The len must be a multiple of
+ * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
+ * and addr must be a multiple of sizeof(VECTYPE) due to
+ * restriction of optimizations in this function.
+ *
+ * can_use_buffer_find_nonzero_offset_inner() can be used to
+ * check these requirements.
+ *
+ * The return value is the offset of the non-zero area rounded
+ * down to a multiple of sizeof(VECTYPE) for the first
+ * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
+ * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
+ * afterwards.
+ *
+ * If the buffer is all zero the return value is equal to len.
+ */
+
+static size_t buffer_find_nonzero_offset_inner(const void *buf, size_t len)
+{
+ const VECTYPE *p = buf;
+ const VECTYPE zero = (VECTYPE){0};
+ size_t i;
+
+ assert(can_use_buffer_find_nonzero_offset_inner(buf, len));
+
+ if (!len) {
+ return 0;
+ }
+
+ for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
+ if (!ALL_EQ(p[i], zero)) {
+ return i * sizeof(VECTYPE);
+ }
+ }
+
+ for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
+ i < len / sizeof(VECTYPE);
+ i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
+ VECTYPE tmp0 = VEC_OR(p[i + 0], p[i + 1]);
+ VECTYPE tmp1 = VEC_OR(p[i + 2], p[i + 3]);
+ VECTYPE tmp2 = VEC_OR(p[i + 4], p[i + 5]);
+ VECTYPE tmp3 = VEC_OR(p[i + 6], p[i + 7]);
+ VECTYPE tmp01 = VEC_OR(tmp0, tmp1);
+ VECTYPE tmp23 = VEC_OR(tmp2, tmp3);
+ if (!ALL_EQ(VEC_OR(tmp01, tmp23), zero)) {
+ break;
+ }
+ }
+
+ return i * sizeof(VECTYPE);
+}
+
+#if defined CONFIG_AVX2_OPT
+#pragma GCC push_options
+#pragma GCC target("avx2")
+#include <cpuid.h>
+#include <immintrin.h>
+
+#define AVX2_VECTYPE __m256i
+#define AVX2_SPLAT(p) _mm256_set1_epi8(*(p))
+#define AVX2_ALL_EQ(v1, v2) \
+ (_mm256_movemask_epi8(_mm256_cmpeq_epi8(v1, v2)) == 0xFFFFFFFF)
+#define AVX2_VEC_OR(v1, v2) (_mm256_or_si256(v1, v2))
+
+static bool
+can_use_buffer_find_nonzero_offset_avx2(const void *buf, size_t len)
+{
+ return (len % (BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR
+ * sizeof(AVX2_VECTYPE)) == 0
+ && ((uintptr_t) buf) % sizeof(AVX2_VECTYPE) == 0);
+}
+
+static size_t buffer_find_nonzero_offset_avx2(const void *buf, size_t len)
+{
+ const AVX2_VECTYPE *p = buf;
+ const AVX2_VECTYPE zero = (AVX2_VECTYPE){0};
+ size_t i;
+
+ assert(can_use_buffer_find_nonzero_offset_avx2(buf, len));
+
+ if (!len) {
+ return 0;
+ }
+
+ for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
+ if (!AVX2_ALL_EQ(p[i], zero)) {
+ return i * sizeof(AVX2_VECTYPE);
+ }
+ }
+
+ for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
+ i < len / sizeof(AVX2_VECTYPE);
+ i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
+ AVX2_VECTYPE tmp0 = AVX2_VEC_OR(p[i + 0], p[i + 1]);
+ AVX2_VECTYPE tmp1 = AVX2_VEC_OR(p[i + 2], p[i + 3]);
+ AVX2_VECTYPE tmp2 = AVX2_VEC_OR(p[i + 4], p[i + 5]);
+ AVX2_VECTYPE tmp3 = AVX2_VEC_OR(p[i + 6], p[i + 7]);
+ AVX2_VECTYPE tmp01 = AVX2_VEC_OR(tmp0, tmp1);
+ AVX2_VECTYPE tmp23 = AVX2_VEC_OR(tmp2, tmp3);
+ if (!AVX2_ALL_EQ(AVX2_VEC_OR(tmp01, tmp23), zero)) {
+ break;
+ }
+ }
+
+ return i * sizeof(AVX2_VECTYPE);
+}
+
+static bool avx2_support(void)
+{
+ int a, b, c, d;
+
+ if (__get_cpuid_max(0, NULL) < 7) {
+ return false;
+ }
+
+ __cpuid_count(7, 0, a, b, c, d);
+
+ return b & bit_AVX2;
+}
+
+bool can_use_buffer_find_nonzero_offset(const void *buf, size_t len) \
+ __attribute__ ((ifunc("can_use_buffer_find_nonzero_offset_ifunc")));
+size_t buffer_find_nonzero_offset(const void *buf, size_t len) \
+ __attribute__ ((ifunc("buffer_find_nonzero_offset_ifunc")));
+
+static void *buffer_find_nonzero_offset_ifunc(void)
+{
+ typeof(buffer_find_nonzero_offset) *func = (avx2_support()) ?
+ buffer_find_nonzero_offset_avx2 : buffer_find_nonzero_offset_inner;
+
+ return func;
+}
+
+static void *can_use_buffer_find_nonzero_offset_ifunc(void)
+{
+ typeof(can_use_buffer_find_nonzero_offset) *func = (avx2_support()) ?
+ can_use_buffer_find_nonzero_offset_avx2 :
+ can_use_buffer_find_nonzero_offset_inner;
+
+ return func;
+}
+#pragma GCC pop_options
+#else
+bool can_use_buffer_find_nonzero_offset(const void *buf, size_t len)
+{
+ return can_use_buffer_find_nonzero_offset_inner(buf, len);
+}
+
+size_t buffer_find_nonzero_offset(const void *buf, size_t len)
+{
+ return buffer_find_nonzero_offset_inner(buf, len);
+}
+#endif
+
+/*
+ * Checks if a buffer is all zeroes
+ *
+ * Attention! The len must be a multiple of 4 * sizeof(long) due to
+ * restriction of optimizations in this function.
+ */
+bool buffer_is_zero(const void *buf, size_t len)
+{
+ /*
+ * Use long as the biggest available internal data type that fits into the
+ * CPU register and unroll the loop to smooth out the effect of memory
+ * latency.
+ */
+
+ size_t i;
+ long d0, d1, d2, d3;
+ const long * const data = buf;
+
+ /* use vector optimized zero check if possible */
+ if (can_use_buffer_find_nonzero_offset(buf, len)) {
+ return buffer_find_nonzero_offset(buf, len) == len;
+ }
+
+ assert(len % (4 * sizeof(long)) == 0);
+ len /= sizeof(long);
+
+ for (i = 0; i < len; i += 4) {
+ d0 = data[i + 0];
+ d1 = data[i + 1];
+ d2 = data[i + 2];
+ d3 = data[i + 3];
+
+ if (d0 || d1 || d2 || d3) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
diff --git a/util/cutils.c b/util/cutils.c
index 7505fda..4fefcf3 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -161,250 +161,6 @@
#endif
}
-/* vector definitions */
-#ifdef __ALTIVEC__
-#include <altivec.h>
-/* The altivec.h header says we're allowed to undef these for
- * C++ compatibility. Here we don't care about C++, but we
- * undef them anyway to avoid namespace pollution.
- */
-#undef vector
-#undef pixel
-#undef bool
-#define VECTYPE __vector unsigned char
-#define SPLAT(p) vec_splat(vec_ld(0, p), 0)
-#define ALL_EQ(v1, v2) vec_all_eq(v1, v2)
-#define VEC_OR(v1, v2) ((v1) | (v2))
-/* altivec.h may redefine the bool macro as vector type.
- * Reset it to POSIX semantics. */
-#define bool _Bool
-#elif defined __SSE2__
-#include <emmintrin.h>
-#define VECTYPE __m128i
-#define SPLAT(p) _mm_set1_epi8(*(p))
-#define ALL_EQ(v1, v2) (_mm_movemask_epi8(_mm_cmpeq_epi8(v1, v2)) == 0xFFFF)
-#define VEC_OR(v1, v2) (_mm_or_si128(v1, v2))
-#elif defined(__aarch64__)
-#include "arm_neon.h"
-#define VECTYPE uint64x2_t
-#define ALL_EQ(v1, v2) \
- ((vgetq_lane_u64(v1, 0) == vgetq_lane_u64(v2, 0)) && \
- (vgetq_lane_u64(v1, 1) == vgetq_lane_u64(v2, 1)))
-#define VEC_OR(v1, v2) ((v1) | (v2))
-#else
-#define VECTYPE unsigned long
-#define SPLAT(p) (*(p) * (~0UL / 255))
-#define ALL_EQ(v1, v2) ((v1) == (v2))
-#define VEC_OR(v1, v2) ((v1) | (v2))
-#endif
-
-#define BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR 8
-
-static bool
-can_use_buffer_find_nonzero_offset_inner(const void *buf, size_t len)
-{
- return (len % (BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR
- * sizeof(VECTYPE)) == 0
- && ((uintptr_t) buf) % sizeof(VECTYPE) == 0);
-}
-
-/*
- * Searches for an area with non-zero content in a buffer
- *
- * Attention! The len must be a multiple of
- * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
- * and addr must be a multiple of sizeof(VECTYPE) due to
- * restriction of optimizations in this function.
- *
- * can_use_buffer_find_nonzero_offset_inner() can be used to
- * check these requirements.
- *
- * The return value is the offset of the non-zero area rounded
- * down to a multiple of sizeof(VECTYPE) for the first
- * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
- * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
- * afterwards.
- *
- * If the buffer is all zero the return value is equal to len.
- */
-
-static size_t buffer_find_nonzero_offset_inner(const void *buf, size_t len)
-{
- const VECTYPE *p = buf;
- const VECTYPE zero = (VECTYPE){0};
- size_t i;
-
- assert(can_use_buffer_find_nonzero_offset_inner(buf, len));
-
- if (!len) {
- return 0;
- }
-
- for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
- if (!ALL_EQ(p[i], zero)) {
- return i * sizeof(VECTYPE);
- }
- }
-
- for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
- i < len / sizeof(VECTYPE);
- i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
- VECTYPE tmp0 = VEC_OR(p[i + 0], p[i + 1]);
- VECTYPE tmp1 = VEC_OR(p[i + 2], p[i + 3]);
- VECTYPE tmp2 = VEC_OR(p[i + 4], p[i + 5]);
- VECTYPE tmp3 = VEC_OR(p[i + 6], p[i + 7]);
- VECTYPE tmp01 = VEC_OR(tmp0, tmp1);
- VECTYPE tmp23 = VEC_OR(tmp2, tmp3);
- if (!ALL_EQ(VEC_OR(tmp01, tmp23), zero)) {
- break;
- }
- }
-
- return i * sizeof(VECTYPE);
-}
-
-#if defined CONFIG_AVX2_OPT
-#pragma GCC push_options
-#pragma GCC target("avx2")
-#include <cpuid.h>
-#include <immintrin.h>
-
-#define AVX2_VECTYPE __m256i
-#define AVX2_SPLAT(p) _mm256_set1_epi8(*(p))
-#define AVX2_ALL_EQ(v1, v2) \
- (_mm256_movemask_epi8(_mm256_cmpeq_epi8(v1, v2)) == 0xFFFFFFFF)
-#define AVX2_VEC_OR(v1, v2) (_mm256_or_si256(v1, v2))
-
-static bool
-can_use_buffer_find_nonzero_offset_avx2(const void *buf, size_t len)
-{
- return (len % (BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR
- * sizeof(AVX2_VECTYPE)) == 0
- && ((uintptr_t) buf) % sizeof(AVX2_VECTYPE) == 0);
-}
-
-static size_t buffer_find_nonzero_offset_avx2(const void *buf, size_t len)
-{
- const AVX2_VECTYPE *p = buf;
- const AVX2_VECTYPE zero = (AVX2_VECTYPE){0};
- size_t i;
-
- assert(can_use_buffer_find_nonzero_offset_avx2(buf, len));
-
- if (!len) {
- return 0;
- }
-
- for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
- if (!AVX2_ALL_EQ(p[i], zero)) {
- return i * sizeof(AVX2_VECTYPE);
- }
- }
-
- for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
- i < len / sizeof(AVX2_VECTYPE);
- i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
- AVX2_VECTYPE tmp0 = AVX2_VEC_OR(p[i + 0], p[i + 1]);
- AVX2_VECTYPE tmp1 = AVX2_VEC_OR(p[i + 2], p[i + 3]);
- AVX2_VECTYPE tmp2 = AVX2_VEC_OR(p[i + 4], p[i + 5]);
- AVX2_VECTYPE tmp3 = AVX2_VEC_OR(p[i + 6], p[i + 7]);
- AVX2_VECTYPE tmp01 = AVX2_VEC_OR(tmp0, tmp1);
- AVX2_VECTYPE tmp23 = AVX2_VEC_OR(tmp2, tmp3);
- if (!AVX2_ALL_EQ(AVX2_VEC_OR(tmp01, tmp23), zero)) {
- break;
- }
- }
-
- return i * sizeof(AVX2_VECTYPE);
-}
-
-static bool avx2_support(void)
-{
- int a, b, c, d;
-
- if (__get_cpuid_max(0, NULL) < 7) {
- return false;
- }
-
- __cpuid_count(7, 0, a, b, c, d);
-
- return b & bit_AVX2;
-}
-
-bool can_use_buffer_find_nonzero_offset(const void *buf, size_t len) \
- __attribute__ ((ifunc("can_use_buffer_find_nonzero_offset_ifunc")));
-size_t buffer_find_nonzero_offset(const void *buf, size_t len) \
- __attribute__ ((ifunc("buffer_find_nonzero_offset_ifunc")));
-
-static void *buffer_find_nonzero_offset_ifunc(void)
-{
- typeof(buffer_find_nonzero_offset) *func = (avx2_support()) ?
- buffer_find_nonzero_offset_avx2 : buffer_find_nonzero_offset_inner;
-
- return func;
-}
-
-static void *can_use_buffer_find_nonzero_offset_ifunc(void)
-{
- typeof(can_use_buffer_find_nonzero_offset) *func = (avx2_support()) ?
- can_use_buffer_find_nonzero_offset_avx2 :
- can_use_buffer_find_nonzero_offset_inner;
-
- return func;
-}
-#pragma GCC pop_options
-#else
-bool can_use_buffer_find_nonzero_offset(const void *buf, size_t len)
-{
- return can_use_buffer_find_nonzero_offset_inner(buf, len);
-}
-
-size_t buffer_find_nonzero_offset(const void *buf, size_t len)
-{
- return buffer_find_nonzero_offset_inner(buf, len);
-}
-#endif
-
-/*
- * Checks if a buffer is all zeroes
- *
- * Attention! The len must be a multiple of 4 * sizeof(long) due to
- * restriction of optimizations in this function.
- */
-bool buffer_is_zero(const void *buf, size_t len)
-{
- /*
- * Use long as the biggest available internal data type that fits into the
- * CPU register and unroll the loop to smooth out the effect of memory
- * latency.
- */
-
- size_t i;
- long d0, d1, d2, d3;
- const long * const data = buf;
-
- /* use vector optimized zero check if possible */
- if (can_use_buffer_find_nonzero_offset(buf, len)) {
- return buffer_find_nonzero_offset(buf, len) == len;
- }
-
- assert(len % (4 * sizeof(long)) == 0);
- len /= sizeof(long);
-
- for (i = 0; i < len; i += 4) {
- d0 = data[i + 0];
- d1 = data[i + 1];
- d2 = data[i + 2];
- d3 = data[i + 3];
-
- if (d0 || d1 || d2 || d3) {
- return false;
- }
- }
-
- return true;
-}
-
#ifndef _WIN32
/* Sets a specific flag */
int fcntl_setfl(int fd, int flag)
