lib/lzo: add unlikely hints to overrun checks

The NEED_* macros do an implicit goto in case the safety bounds checks
fail. Add the unlikely hints as this is the error case and not a hot
path. The final assembly is slightly shorter and some jumps got
reordered according to the hints.

   text    data     bss     dec     hex filename
   2294      16       0    2310     906 pre/lzo1x_decompress_safe.o
   2277      16       0    2293     8f5 post/lzo1x_decompress_safe.o

   text    data     bss     dec     hex filename
   3444      48       0    3492     da4 pre/lzo1x_compress_safe.o
   3372      48       0    3420     d5c post/lzo1x_compress_safe.o

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
index 7b10ca86a89300d8febfc3d2564aa4e407ed2c07..01586af2347f5e2f8c8528b94e02622fc8b262c8 100644 (file)
--- a/lib/lzo/lzo1x_compress.c
+++ b/lib/lzo/lzo1x_compress.c
@@ -26,7 +26,7 @@
 #define HAVE_OP(x) 1
 #endif
 
-#define NEED_OP(x) if (!HAVE_OP(x)) goto output_overrun
+#define NEED_OP(x) if (unlikely(!HAVE_OP(x))) goto output_overrun
 
 static noinline int
 LZO_SAFE(lzo1x_1_do_compress)(const unsigned char *in, size_t in_len,

diff --git a/lib/lzo/lzo1x_decompress_safe.c b/lib/lzo/lzo1x_decompress_safe.c
index c94f4928e1888be8de03585081e0a34bd2f5c6da..318abb82c63d2c27c0d5497b7cf4e21d87d13154 100644 (file)
--- a/lib/lzo/lzo1x_decompress_safe.c
+++ b/lib/lzo/lzo1x_decompress_safe.c
@@ -22,9 +22,9 @@
 
 #define HAVE_IP(x)      ((size_t)(ip_end - ip) >= (size_t)(x))
 #define HAVE_OP(x)      ((size_t)(op_end - op) >= (size_t)(x))
-#define NEED_IP(x)      if (!HAVE_IP(x)) goto input_overrun
-#define NEED_OP(x)      if (!HAVE_OP(x)) goto output_overrun
-#define TEST_LB(m_pos)  if ((m_pos) < out) goto lookbehind_overrun
+#define NEED_IP(x)      if (unlikely(!HAVE_IP(x))) goto input_overrun
+#define NEED_OP(x)      if (unlikely(!HAVE_OP(x))) goto output_overrun
+#define TEST_LB(m_pos)  if (unlikely((m_pos) < out)) goto lookbehind_overrun
 
 /* This MAX_255_COUNT is the maximum number of times we can add 255 to a base
  * count without overflowing an integer. The multiply will overflow when