On Thu, Sep 10, 2020 at 10:51:18PM +0900, Masahiro Yamada wrote: > The minimal compiler versions, GCC 4.9 and Clang 10 support this flag. > > Here is the godbolt: > https://godbolt.org/z/8T4177 > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> For what it's worth, the commit that introduced this block is going to be reverted: https://lore.kernel.org/mm-commits/20200903201518.JKrRS%25akpm@xxxxxxxxxxxxxxxxxxxx/ Regardless, it was introduced in LLVM 2.7.0 in commit f9d41df0930986c52e198292cf875eb5d1761ece. Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > > Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index 059b36f2ea53..1b6abecc5cab 100644 > --- a/Makefile > +++ b/Makefile > @@ -927,7 +927,7 @@ KBUILD_CFLAGS += -fno-strict-overflow > # clang sets -fmerge-all-constants by default as optimization, but this > # is non-conforming behavior for C and in fact breaks the kernel, so we > # need to disable it here generally. > -KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants) > +KBUILD_CFLAGS += -fno-merge-all-constants > > # for gcc -fno-merge-all-constants disables everything, but it is fine > # to have actual conforming behavior enabled. > -- > 2.25.1 >
