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>

1 files changed, 0 insertions, 244 deletions

diff --git a/util/cutils.c b/util/cutils.c
index 7505fdaa81..4fefcf3be3 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -161,250 +161,6 @@ int qemu_fdatasync(int fd)
 #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)