Add support for ARM ACLE instructions.

1 files changed, 50 insertions, 0 deletions

diff --git a/arch/arm/insert_string_acle.c b/arch/arm/insert_string_acle.c
new file mode 100644
index 0000000..985b726
--- /dev/null
+++ b/arch/arm/insert_string_acle.c
@@ -0,0 +1,50 @@
+/* insert_string_acle.c -- insert_string variant using ACLE's CRC instructions
+ *
+ * Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ */
+
+#ifdef __ARM_FEATURE_CRC32
+#include <arm_acle.h>
+#endif
+#include "deflate.h"
+
+/* ===========================================================================
+ * Insert string str in the dictionary and set match_head to the previous head
+ * of the hash chain (the most recent string with same hash key). Return
+ * the previous length of the hash chain.
+ * IN  assertion: all calls to to INSERT_STRING are made with consecutive
+ *    input characters and the first MIN_MATCH bytes of str are valid
+ *    (except for the last MIN_MATCH-1 bytes of the input file).
+ */
+#ifdef ARM_ACLE_CRC_HASH
+Pos insert_string_acle(deflate_state *const s, const Pos str, unsigned int count) {
+    Pos p, lp;
+
+    if (unlikely(count == 0)) {
+        return s->prev[str & s->w_mask];
+    }
+
+    lp = str + count - 1; /* last position */
+
+    for (p = str; p <= lp; p++) {
+        unsigned *ip, val, h, hm;
+
+        ip = (unsigned *)&s->window[p];
+        val = *ip;
+
+        if (s->level >= TRIGGER_LEVEL)
+            val &= 0xFFFFFF;
+
+        h = __crc32w(0, val);
+        hm = h & s->hash_mask;
+
+        if (s->head[hm] != p) {
+            s->prev[p & s->w_mask] = s->head[hm];
+            s->head[hm] = p;
+        }
+    }
+    return s->prev[lp & s->w_mask];
+}
+#endif