1 files changed, 60 insertions, 0 deletions
diff --git a/src/zlib-ng/arch/arm/compare256_neon.c b/src/zlib-ng/arch/arm/compare256_neon.c
new file mode 100644
index 0000000..53a088c
--- /dev/null
+++ b/src/zlib-ng/arch/arm/compare256_neon.c
@@ -0,0 +1,60 @@
+/* compare256_neon.c - NEON version of compare256
+ * Copyright (C) 2022 Nathan Moinvaziri
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#if defined(ARM_NEON) && defined(HAVE_BUILTIN_CTZLL)
+#ifdef _M_ARM64
+#  include <arm64_neon.h>
+#else
+#  include <arm_neon.h>
+#endif
+#include "../../zbuild.h"
+
+static inline uint32_t compare256_neon_static(const uint8_t *src0, const uint8_t *src1) {
+    uint32_t len = 0;
+
+    do {
+        uint8x16_t a, b, cmp;
+        uint64_t lane;
+
+        a = vld1q_u8(src0);
+        b = vld1q_u8(src1);
+
+        cmp = veorq_u8(a, b);
+
+        lane = vgetq_lane_u64(vreinterpretq_u64_u8(cmp), 0);
+        if (lane) {
+            uint32_t match_byte = (uint32_t)__builtin_ctzll(lane) / 8;
+            return len + match_byte;
+        }
+        len += 8;
+        lane = vgetq_lane_u64(vreinterpretq_u64_u8(cmp), 1);
+        if (lane) {
+            uint32_t match_byte = (uint32_t)__builtin_ctzll(lane) / 8;
+            return len + match_byte;
+        }
+        len += 8;
+
+        src0 += 16, src1 += 16;
+    } while (len < 256);
+
+    return 256;
+}
+
+Z_INTERNAL uint32_t compare256_neon(const uint8_t *src0, const uint8_t *src1) {
+    return compare256_neon_static(src0, src1);
+}
+
+#define LONGEST_MATCH       longest_match_neon
+#define COMPARE256          compare256_neon_static
+
+#include "match_tpl.h"
+
+#define LONGEST_MATCH_SLOW
+#define LONGEST_MATCH       longest_match_slow_neon
+#define COMPARE256          compare256_neon_static
+
+#include "match_tpl.h"
+
+#endif