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lib/lzo: add unlikely hints to overrun checks

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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>
This commit is contained in:
David Sterba
2025-08-07 13:44:44 +02:00
committed by Herbert Xu
parent 817fcdbd4c
commit d223619883
2 changed files with 4 additions and 4 deletions
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2
lib/lzo/lzo1x_compress.c
View File

@@ -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,

6
lib/lzo/lzo1x_decompress_safe.c
View File

@@ -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