[linux-next:master 6206/13220] lib/zstd/decompress/zstd_decompress_block.c:982:69-70: WARNING opportunity for swap()

[linux-next:master 6206/13220] lib/zstd/decompress/zstd_decompress_block.c:982:69-70: WARNING opportunity for swap()

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
CC: Linux Memory Management List <linux-mm@kvack.org>
TO: Nick Terrell <terrelln@fb.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   6a37ebbe07bf72cd5fd791d67a664f37c8f17a13
commit: ecea7adad80d9d230df766345e5f8061792da00d [6206/13220] lib: zstd: Upgrade to latest upstream zstd version 1.4.10
:::::: branch date: 30 hours ago
:::::: commit date: 4 weeks ago
config: x86_64-rhel-8.3-kselftests (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>


cocci warnings: (new ones prefixed by >>)
>> lib/zstd/decompress/zstd_decompress_block.c:982:69-70: WARNING opportunity for swap()

Please review and possibly fold the followup patch.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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[PATCH] lib: zstd: fix swap.cocci warnings

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
CC: Linux Memory Management List <linux-mm@kvack.org>
TO: Nick Terrell <terrelln@fb.com>

From: kernel test robot <lkp@intel.com>

lib/zstd/decompress/zstd_decompress_block.c:982:69-70: WARNING opportunity for swap()


 Check for opencoded swap() implementation.

Generated by: scripts/coccinelle/misc/swap.cocci

Fixes: ecea7adad80d ("lib: zstd: Upgrade to latest upstream zstd version 1.4.10")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
---

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   6a37ebbe07bf72cd5fd791d67a664f37c8f17a13
commit: ecea7adad80d9d230df766345e5f8061792da00d [6206/13220] lib: zstd: Upgrade to latest upstream zstd version 1.4.10
:::::: branch date: 30 hours ago
:::::: commit date: 4 weeks ago

Please take the patch only if it's a positive warning. Thanks!

 zstd_decompress_block.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/lib/zstd/decompress/zstd_decompress_block.c
+++ b/lib/zstd/decompress/zstd_decompress_block.c
@@ -978,9 +978,7 @@ ZSTD_decodeSequence(seqState_t* seqState
                 if (LIKELY(!ll0))
                     offset = seqState->prevOffset[0];
                 else {
-                    offset = seqState->prevOffset[1];
-                    seqState->prevOffset[1] = seqState->prevOffset[0];
-                    seqState->prevOffset[0] = offset;
+                    swap(seqState->prevOffset[1], seqState->prevOffset[0]);
                 }
             } else {
                 offset = ofBase + ll0 + BIT_readBitsFast(&seqState->DStream, 1);