From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
Nathan Chancellor <natechancellor@gmail.com>,
Nick Desaulniers <ndesaulniers@google.com>,
clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [PATCH 2/4] kbuild: remove cc-option test of -fno-merge-all-constants
Date: Thu, 10 Sep 2020 22:51:18 +0900 [thread overview]
Message-ID: <20200910135120.3527468-2-masahiroy@kernel.org> (raw)
In-Reply-To: <20200910135120.3527468-1-masahiroy@kernel.org>
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@kernel.org>
---
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
next prev parent reply other threads:[~2020-09-10 21:11 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 13:51 [PATCH 1/4] kbuild: remove cc-option test of -fno-strict-overflow Masahiro Yamada
2020-09-10 13:51 ` Masahiro Yamada
2020-09-10 13:51 ` Masahiro Yamada [this message]
2020-09-10 16:33 ` [PATCH 2/4] kbuild: remove cc-option test of -fno-merge-all-constants Nathan Chancellor
2020-09-10 16:41 ` Masahiro Yamada
2020-09-10 13:51 ` [PATCH 3/4] kbuild: remove cc-option test of -fno-stack-check Masahiro Yamada
2020-09-10 16:37 ` Nathan Chancellor
2020-09-10 13:51 ` [PATCH 4/4] kbuild: remove cc-option test of -Werror=date-time Masahiro Yamada
2020-09-10 13:51 ` Masahiro Yamada
2020-09-10 16:43 ` Nathan Chancellor
2020-09-10 16:43 ` Nathan Chancellor
2020-09-10 16:26 ` [PATCH 1/4] kbuild: remove cc-option test of -fno-strict-overflow Nathan Chancellor
2020-09-10 16:26 ` Nathan Chancellor
2020-09-11 15:22 ` Will Deacon
2020-09-11 15:22 ` Will Deacon
2020-09-14 12:51 ` Masahiro Yamada
2020-09-14 12:51 ` Masahiro Yamada
2020-09-14 13:20 ` Will Deacon
2020-09-14 13:20 ` Will Deacon
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