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authorRichard Henderson <richard.henderson@linaro.org>2024-06-05 20:58:37 -0700
committerRichard Henderson <richard.henderson@linaro.org>2024-06-19 12:47:11 -0700
commit2d32a5d2a06a524c5e7967f918c406ec99418a34 (patch)
treed042442e48299e2964ff1d77c076e730f73e5182 /util/bufferiszero.c
parent6b0ca412e16dae52bf1ef2da9436d4d8c81759f2 (diff)
downloadfocaccia-qemu-2d32a5d2a06a524c5e7967f918c406ec99418a34.tar.gz
focaccia-qemu-2d32a5d2a06a524c5e7967f918c406ec99418a34.zip
util/bufferiszero: Split out host include files
Split out host/bufferiszero.h.inc for x86, aarch64 and generic
in order to avoid an overlong ifdef ladder.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'util/bufferiszero.c')
-rw-r--r--util/bufferiszero.c191
1 files changed, 1 insertions, 190 deletions
diff --git a/util/bufferiszero.c b/util/bufferiszero.c
index 11c080e02c..522146dab9 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.c.inc"
 
 static biz_accel_fn buffer_is_zero_accel;
 static unsigned accel_index;