1 files changed, 56 insertions, 0 deletions
diff --git a/neozip/arch/arm/compare256_neon.c b/neozip/arch/arm/compare256_neon.c
new file mode 100644
index 0000000000..4ced9fc9ca
--- /dev/null
+++ b/neozip/arch/arm/compare256_neon.c
@@ -0,0 +1,56 @@
+/* compare256_neon.c - NEON version of compare256
+ * Copyright (C) 2022 Nathan Moinvaziri
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zbuild.h"
+#include "zmemory.h"
+#include "deflate.h"
+#include "fallback_builtins.h"
+
+#if defined(ARM_NEON)
+#include "neon_intrins.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)
+            return len + zng_ctz64(lane) / 8;
+        len += 8;
+        lane = vgetq_lane_u64(vreinterpretq_u64_u8(cmp), 1);
+        if (lane)
+            return len + zng_ctz64(lane) / 8;
+        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