1 files changed, 68 insertions, 0 deletions
diff --git a/neozip/arch/power/compare256_power9.c b/neozip/arch/power/compare256_power9.c
new file mode 100644
index 0000000000..99c3b0b6d1
--- /dev/null
+++ b/neozip/arch/power/compare256_power9.c
@@ -0,0 +1,68 @@
+/* compare256_power9.c - Power9 version of compare256
+ * Copyright (C) 2019 Matheus Castanho <msc@linux.ibm.com>, IBM
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#ifdef POWER9
+
+#include "zbuild.h"
+#include "zmemory.h"
+#include "deflate.h"
+#include "zendian.h"
+
+#include <altivec.h>
+
+/* Older versions of GCC misimplemented semantics for these bit counting builtins.
+ * https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=3f30f2d1dbb3228b8468b26239fe60c2974ce2ac */
+#if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 12)
+#if BYTE_ORDER == LITTLE_ENDIAN
+#  define zng_vec_vctzlsbb(vc, len) len = __builtin_vec_vctzlsbb(vc)
+#else
+#  define zng_vec_vctzlsbb(vc, len) len = __builtin_vec_vclzlsbb(vc)
+#endif
+#else
+#  define zng_vec_vctzlsbb(vc, len) len = vec_cntlz_lsbb(vc)
+#endif
+
+static inline uint32_t compare256_power9_static(const uint8_t *src0, const uint8_t *src1) {
+    uint32_t len = 0, cmplen;
+
+    do {
+        vector unsigned char vsrc0, vsrc1, vc;
+
+        vsrc0 = *((vector unsigned char *)src0);
+        vsrc1 = *((vector unsigned char *)src1);
+
+        /* Compare 16 bytes at a time. Each byte of vc will be either
+         * all ones or all zeroes, depending on the result of the comparison. */
+        vc = (vector unsigned char)vec_cmpne(vsrc0, vsrc1);
+
+        /* Since the index of matching bytes will contain only zeroes
+         * on vc (since we used cmpne), counting the number of consecutive
+         * bytes where LSB == 0 is the same as counting the length of the match. */
+        zng_vec_vctzlsbb(vc, cmplen);
+        if (cmplen != 16)
+            return len + cmplen;
+
+        src0 += 16, src1 += 16, len += 16;
+    } while (len < 256);
+
+   return 256;
+}
+
+Z_INTERNAL uint32_t compare256_power9(const uint8_t *src0, const uint8_t *src1) {
+    return compare256_power9_static(src0, src1);
+}
+
+#define LONGEST_MATCH       longest_match_power9
+#define COMPARE256          compare256_power9_static
+
+#include "match_tpl.h"
+
+#define LONGEST_MATCH_SLOW
+#define LONGEST_MATCH       longest_match_slow_power9
+#define COMPARE256          compare256_power9_static
+
+#include "match_tpl.h"
+
+#endif