summaryrefslogtreecommitdiff
path: root/lib/zlib_inflate/inffast.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/zlib_inflate/inffast.c')
-rw-r--r--lib/zlib_inflate/inffast.c75
1 files changed, 68 insertions, 7 deletions
diff --git a/lib/zlib_inflate/inffast.c b/lib/zlib_inflate/inffast.c
index 8550b0c05d0..215447c5526 100644
--- a/lib/zlib_inflate/inffast.c
+++ b/lib/zlib_inflate/inffast.c
@@ -8,6 +8,21 @@
#include "inflate.h"
#include "inffast.h"
+/* Only do the unaligned "Faster" variant when
+ * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set
+ *
+ * On powerpc, it won't be as we don't include autoconf.h
+ * automatically for the boot wrapper, which is intended as
+ * we run in an environment where we may not be able to deal
+ * with (even rare) alignment faults. In addition, we do not
+ * define __KERNEL__ for arch/powerpc/boot unlike x86
+ */
+
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+#include <asm/unaligned.h>
+#include <asm/byteorder.h>
+#endif
+
#ifndef ASMINF
/* Allow machine dependent optimization for post-increment or pre-increment.
@@ -24,9 +39,11 @@
#ifdef POSTINC
# define OFF 0
# define PUP(a) *(a)++
+# define UP_UNALIGNED(a) get_unaligned((a)++)
#else
# define OFF 1
# define PUP(a) *++(a)
+# define UP_UNALIGNED(a) get_unaligned(++(a))
#endif
/*
@@ -239,18 +256,62 @@ void inflate_fast(z_streamp strm, unsigned start)
}
}
else {
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ unsigned short *sout;
+ unsigned long loops;
+
+ from = out - dist; /* copy direct from output */
+ /* minimum length is three */
+ /* Align out addr */
+ if (!((long)(out - 1 + OFF) & 1)) {
+ PUP(out) = PUP(from);
+ len--;
+ }
+ sout = (unsigned short *)(out - OFF);
+ if (dist > 2) {
+ unsigned short *sfrom;
+
+ sfrom = (unsigned short *)(from - OFF);
+ loops = len >> 1;
+ do
+ PUP(sout) = UP_UNALIGNED(sfrom);
+ while (--loops);
+ out = (unsigned char *)sout + OFF;
+ from = (unsigned char *)sfrom + OFF;
+ } else { /* dist == 1 or dist == 2 */
+ unsigned short pat16;
+
+ pat16 = *(sout-2+2*OFF);
+ if (dist == 1)
+#if defined(__BIG_ENDIAN)
+ pat16 = (pat16 & 0xff) | ((pat16 & 0xff) << 8);
+#elif defined(__LITTLE_ENDIAN)
+ pat16 = (pat16 & 0xff00) | ((pat16 & 0xff00) >> 8);
+#else
+#error __BIG_ENDIAN nor __LITTLE_ENDIAN is defined
+#endif
+ loops = len >> 1;
+ do
+ PUP(sout) = pat16;
+ while (--loops);
+ out = (unsigned char *)sout + OFF;
+ }
+ if (len & 1)
+ PUP(out) = PUP(from);
+#else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
from = out - dist; /* copy direct from output */
do { /* minimum length is three */
- PUP(out) = PUP(from);
- PUP(out) = PUP(from);
- PUP(out) = PUP(from);
- len -= 3;
+ PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ len -= 3;
} while (len > 2);
if (len) {
- PUP(out) = PUP(from);
- if (len > 1)
- PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ if (len > 1)
+ PUP(out) = PUP(from);
}
+#endif /* !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
}
}
else if ((op & 64) == 0) { /* 2nd level distance code */