* Re: [PATCH] powerpc: replace ternary operator with min()
2022-10-23 12:44 [PATCH] powerpc: replace ternary operator with min() KaiLong Wang
@ 2022-10-24 4:33 ` Russell Currey
2022-11-02 9:23 ` Christophe Leroy
2022-10-26 12:07 ` kernel test robot
1 sibling, 1 reply; 4+ messages in thread
From: Russell Currey @ 2022-10-24 4:33 UTC (permalink / raw)
To: KaiLong Wang, mpe, npiggin, christophe.leroy, farosas, mirq-linux,
dmitry.osipenko, kda, naveen.n.rao
Cc: linuxppc-dev, linux-kernel
On Sun, 2022-10-23 at 20:44 +0800, KaiLong Wang wrote:
> Fix the following coccicheck warning:
>
> arch/powerpc/xmon/xmon.c:2987: WARNING opportunity for min()
> arch/powerpc/xmon/xmon.c:2583: WARNING opportunity for min()
>
> Signed-off-by: KaiLong Wang <wangkailong@jari.cn>
Hello,
This fails to compile on some platforms/compilers since n is a long and
16 is an int, expanding to:
r = __builtin_choose_expr(
((!!(sizeof((typeof(n) *)1 == (typeof(16) *)1))) &&
((sizeof(int) ==
sizeof(*(8 ? ((void *)((long)(n)*0l)) : (int *)8))) &&
(sizeof(int) ==
sizeof(*(8 ? ((void *)((long)(16) * 0l)) :
(int *)8))))),
((n) < (16) ? (n) : (16)), ({
typeof(n) __UNIQUE_ID___x0 = (n);
typeof(16) __UNIQUE_ID___y1 = (16);
((__UNIQUE_ID___x0) < (__UNIQUE_ID___y1) ?
(__UNIQUE_ID___x0) :
(__UNIQUE_ID___y1));
}));
Here's the full build failure as found by snowpatch:
https://github.com/ruscur/linux-ci/actions/runs/3308880562/jobs/5461579048#step:4:89
You should use min_t(long, n, 16) instead.
- Russell
> ---
> arch/powerpc/xmon/xmon.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index f51c882bf902..a7751cd2cc9d 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -2580,7 +2580,7 @@ static void xmon_rawdump (unsigned long adrs,
> long ndump)
> unsigned char temp[16];
>
> for (n = ndump; n > 0;) {
> - r = n < 16? n: 16;
> + r = min(n, 16);
> nr = mread(adrs, temp, r);
> adrs += nr;
> for (m = 0; m < r; ++m) {
> @@ -2984,7 +2984,7 @@ prdump(unsigned long adrs, long ndump)
> for (n = ndump; n > 0;) {
> printf(REG, adrs);
> putchar(' ');
> - r = n < 16? n: 16;
> + r = min(n, 16);
> nr = mread(adrs, temp, r);
> adrs += nr;
> for (m = 0; m < r; ++m) {
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] powerpc: replace ternary operator with min()
2022-10-23 12:44 [PATCH] powerpc: replace ternary operator with min() KaiLong Wang
2022-10-24 4:33 ` Russell Currey
@ 2022-10-26 12:07 ` kernel test robot
1 sibling, 0 replies; 4+ messages in thread
From: kernel test robot @ 2022-10-26 12:07 UTC (permalink / raw)
To: KaiLong Wang, mpe, npiggin, christophe.leroy, farosas, mirq-linux,
dmitry.osipenko, kda, naveen.n.rao
Cc: llvm, linuxppc-dev, linux-kernel, oe-kbuild-all
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Hi KaiLong,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on powerpc/next]
[also build test ERROR on linus/master v6.1-rc2 next-20221026]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/KaiLong-Wang/powerpc-replace-ternary-operator-with-min/20221023-204906
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
patch link: https://lore.kernel.org/r/4ebda26c.346.18404df6852.Coremail.wangkailong%40jari.cn
patch subject: [PATCH] powerpc: replace ternary operator with min()
config: powerpc-ppc64e_defconfig (attached as .config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc cross compiling tool for clang build
# apt-get install binutils-powerpc-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/51fa624eb9fa01ea67de462263913ab61a68cbc5
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review KaiLong-Wang/powerpc-replace-ternary-operator-with-min/20221023-204906
git checkout 51fa624eb9fa01ea67de462263913ab61a68cbc5
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
>> arch/powerpc/xmon/xmon.c:2583:7: error: comparison of distinct pointer types ('typeof (n) *' (aka 'long *') and 'typeof (16) *' (aka 'int *')) [-Werror,-Wcompare-distinct-pointer-types]
r = min(n, 16);
^~~~~~~~~~
include/linux/minmax.h:45:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:36:24: note: expanded from macro '__careful_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~~~~~~~
include/linux/minmax.h:26:4: note: expanded from macro '__safe_cmp'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~~~~~~~
include/linux/minmax.h:20:28: note: expanded from macro '__typecheck'
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
arch/powerpc/xmon/xmon.c:2987:7: error: comparison of distinct pointer types ('typeof (n) *' (aka 'long *') and 'typeof (16) *' (aka 'int *')) [-Werror,-Wcompare-distinct-pointer-types]
r = min(n, 16);
^~~~~~~~~~
include/linux/minmax.h:45:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:36:24: note: expanded from macro '__careful_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~~~~~~~
include/linux/minmax.h:26:4: note: expanded from macro '__safe_cmp'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~~~~~~~
include/linux/minmax.h:20:28: note: expanded from macro '__typecheck'
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
2 errors generated.
vim +2583 arch/powerpc/xmon/xmon.c
2576
2577 static void xmon_rawdump (unsigned long adrs, long ndump)
2578 {
2579 long n, m, r, nr;
2580 unsigned char temp[16];
2581
2582 for (n = ndump; n > 0;) {
> 2583 r = min(n, 16);
2584 nr = mread(adrs, temp, r);
2585 adrs += nr;
2586 for (m = 0; m < r; ++m) {
2587 if (m < nr)
2588 printf("%.2x", temp[m]);
2589 else
2590 printf("%s", fault_chars[fault_type]);
2591 }
2592 n -= r;
2593 if (nr < r)
2594 break;
2595 }
2596 printf("\n");
2597 }
2598
--
0-DAY CI Kernel Test Service
https://01.org/lkp
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^ permalink raw reply [flat|nested] 4+ messages in thread