target/riscv: add support for Zcf extension

[mirror_qemu.git] / util / bufferiszero.c

diff --git a/util/bufferiszero.c b/util/bufferiszero.c
index b8012532e465679a98b3ff61bd757e72fa6e70ab..1886bc5ba438a7b363def1879ab479e6f74524ed 100644 (file)
--- a/util/bufferiszero.c
+++ b/util/bufferiszero.c
@@ -64,18 +64,11 @@ buffer_zero_int(const void *buf, size_t len)
 }
 
 #if defined(CONFIG_AVX512F_OPT) || defined(CONFIG_AVX2_OPT) || defined(__SSE2__)
-/* Do not use push_options pragmas unnecessarily, because clang
- * does not support them.
- */
-#if defined(CONFIG_AVX512F_OPT) || defined(CONFIG_AVX2_OPT)
-#pragma GCC push_options
-#pragma GCC target("sse2")
-#endif
-#include <emmintrin.h>
+#include <immintrin.h>
 
 /* Note that each of these vectorized functions require len >= 64.  */
 
-static bool
+static bool __attribute__((target("sse2")))
 buffer_zero_sse2(const void *buf, size_t len)
 {
     __m128i t = _mm_loadu_si128(buf);
@@ -104,20 +97,9 @@ buffer_zero_sse2(const void *buf, size_t len)
 
     return _mm_movemask_epi8(_mm_cmpeq_epi8(t, zero)) == 0xFFFF;
 }
-#if defined(CONFIG_AVX512F_OPT) || defined(CONFIG_AVX2_OPT)
-#pragma GCC pop_options
-#endif
 
 #ifdef CONFIG_AVX2_OPT
-/* Note that due to restrictions/bugs wrt __builtin functions in gcc <= 4.8,
- * the includes have to be within the corresponding push_options region, and
- * therefore the regions themselves have to be ordered with increasing ISA.
- */
-#pragma GCC push_options
-#pragma GCC target("sse4")
-#include <smmintrin.h>
-
-static bool
+static bool __attribute__((target("sse4")))
 buffer_zero_sse4(const void *buf, size_t len)
 {
     __m128i t = _mm_loadu_si128(buf);
@@ -145,12 +127,7 @@ buffer_zero_sse4(const void *buf, size_t len)
     return _mm_testz_si128(t, t);
 }
 
-#pragma GCC pop_options
-#pragma GCC push_options
-#pragma GCC target("avx2")
-#include <immintrin.h>
-
-static bool
+static bool __attribute__((target("avx2")))
 buffer_zero_avx2(const void *buf, size_t len)
 {
     /* Begin with an unaligned head of 32 bytes.  */
@@ -158,41 +135,28 @@ buffer_zero_avx2(const void *buf, size_t len)
     __m256i *p = (__m256i *)(((uintptr_t)buf + 5 * 32) & -32);
     __m256i *e = (__m256i *)(((uintptr_t)buf + len) & -32);
 
-    if (likely(p <= e)) {
-        /* Loop over 32-byte aligned blocks of 128.  */
-        do {
-            __builtin_prefetch(p);
-            if (unlikely(!_mm256_testz_si256(t, t))) {
-                return false;
-            }
-            t = p[-4] | p[-3] | p[-2] | p[-1];
-            p += 4;
-        } while (p <= e);
-    } else {
-        t |= _mm256_loadu_si256(buf + 32);
-        if (len <= 128) {
-            goto last2;
+    /* Loop over 32-byte aligned blocks of 128.  */
+    while (p <= e) {
+        __builtin_prefetch(p);
+        if (unlikely(!_mm256_testz_si256(t, t))) {
+            return false;
         }
-    }
+        t = p[-4] | p[-3] | p[-2] | p[-1];
+        p += 4;
+    } ;
 
     /* Finish the last block of 128 unaligned.  */
     t |= _mm256_loadu_si256(buf + len - 4 * 32);
     t |= _mm256_loadu_si256(buf + len - 3 * 32);
- last2:
     t |= _mm256_loadu_si256(buf + len - 2 * 32);
     t |= _mm256_loadu_si256(buf + len - 1 * 32);
 
     return _mm256_testz_si256(t, t);
 }
-#pragma GCC pop_options
 #endif /* CONFIG_AVX2_OPT */
 
 #ifdef CONFIG_AVX512F_OPT
-#pragma GCC push_options
-#pragma GCC target("avx512f")
-#include <immintrin.h>
-
-static bool
+static bool __attribute__((target("avx512f")))
 buffer_zero_avx512(const void *buf, size_t len)
 {
     /* Begin with an unaligned head of 64 bytes.  */
@@ -218,8 +182,7 @@ buffer_zero_avx512(const void *buf, size_t len)
     return !_mm512_test_epi64_mask(t, t);
 
 }
-#pragma GCC pop_options
-#endif
+#endif /* CONFIG_AVX512F_OPT */
 
 
 /* Note that for test_buffer_is_zero_next_accel, the most preferred
@@ -263,7 +226,7 @@ static void init_accel(unsigned cache)
     }
     if (cache & CACHE_AVX2) {
         fn = buffer_zero_avx2;
-        length_to_accel = 64;
+        length_to_accel = 128;
     }
 #endif
 #ifdef CONFIG_AVX512F_OPT
@@ -280,7 +243,7 @@ static void init_accel(unsigned cache)
 
 static void __attribute__((constructor)) init_cpuid_cache(void)
 {
-    int max = __get_cpuid_max(0, NULL);
+    unsigned max = __get_cpuid_max(0, NULL);
     int a, b, c, d;
     unsigned cache = 0;
 
@@ -295,8 +258,7 @@ static void __attribute__((constructor)) init_cpuid_cache(void)
 
         /* We must check that AVX is not just available, but usable.  */
         if ((c & bit_OSXSAVE) && (c & bit_AVX) && max >= 7) {
-            int bv;
-            __asm("xgetbv" : "=a"(bv), "=d"(d) : "c"(0));
+            unsigned bv = xgetbv_low(0);
             __cpuid_count(7, 0, a, b, c, d);
             if ((bv & 0x6) == 0x6 && (b & bit_AVX2)) {
                 cache |= CACHE_AVX2;