Re: [PATCH] tools: drop nonsensical -O6

[Namhyung Kim <namhyung@kernel.org>]

Hello,

On Sun, Sep 08, 2024 at 07:46:41PM +0100, Sam James wrote:
> -O6 is very much not-a-thing. Really, this should've been dropped
> entirely in 49b3cd306e60b9d889c775cb2ebb709f80dd8ae9 instead of just
> passing it for not-Clang.
> 
> Just collapse it down to -O3, instead of "-O6 unless Clang, in which case
> -O3".
> 
> GCC interprets > -O3 as -O3. It doesn't even interpret > -O3 as -Ofast,
> which is a good thing, given -Ofast has specific (non-)requirements for
> code built using it. So, this does nothing except look a bit daft.
> 
> Remove the silliness and also save a few lines in the Makefiles accordingly.
> 
> Signed-off-by: Sam James <sam@gentoo.org>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

> ---
> I promise I'm not completely humourless, but given it's caused
> actual workarounds to be added for Clang, I don't think this is worth keeping.
> 
> Plus it sort of propagates a silly myth that -O6 does anything.
> 
>  tools/lib/api/Makefile     | 4 ----
>  tools/lib/subcmd/Makefile  | 4 +---
>  tools/lib/symbol/Makefile  | 4 ----
>  tools/perf/Makefile.config | 6 +-----
>  4 files changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile
> index 044860ac1ed1c..7f6396087b467 100644
> --- a/tools/lib/api/Makefile
> +++ b/tools/lib/api/Makefile
> @@ -31,11 +31,7 @@ CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
>  CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -U_FORTIFY_SOURCE -fPIC
>  
>  ifeq ($(DEBUG),0)
> -ifeq ($(CC_NO_CLANG), 0)
>    CFLAGS += -O3
> -else
> -  CFLAGS += -O6
> -endif
>  endif
>  
>  ifeq ($(DEBUG),0)
> diff --git a/tools/lib/subcmd/Makefile b/tools/lib/subcmd/Makefile
> index b87213263a5e0..6717b82fc5876 100644
> --- a/tools/lib/subcmd/Makefile
> +++ b/tools/lib/subcmd/Makefile
> @@ -38,10 +38,8 @@ endif
>  
>  ifeq ($(DEBUG),1)
>    CFLAGS += -O0
> -else ifeq ($(CC_NO_CLANG), 0)
> -  CFLAGS += -O3
>  else
> -  CFLAGS += -O6
> +  CFLAGS += -O3
>  endif
>  
>  # Treat warnings as errors unless directed not to
> diff --git a/tools/lib/symbol/Makefile b/tools/lib/symbol/Makefile
> index 13d43c6f92b4a..426b845edfacc 100644
> --- a/tools/lib/symbol/Makefile
> +++ b/tools/lib/symbol/Makefile
> @@ -31,11 +31,7 @@ CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
>  CFLAGS += -ggdb3 -Wall -Wextra -std=gnu11 -U_FORTIFY_SOURCE -fPIC
>  
>  ifeq ($(DEBUG),0)
> -ifeq ($(CC_NO_CLANG), 0)
>    CFLAGS += -O3
> -else
> -  CFLAGS += -O6
> -endif
>  endif
>  
>  ifeq ($(DEBUG),0)
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index fa679db61f622..5d6b08a896150 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -238,11 +238,7 @@ endif
>  
>  ifeq ($(DEBUG),0)
>  CORE_CFLAGS += -DNDEBUG=1
> -ifeq ($(CC_NO_CLANG), 0)
> -  CORE_CFLAGS += -O3
> -else
> -  CORE_CFLAGS += -O6
> -endif
> +CORE_CFLAGS += -O3
>  else
>    CORE_CFLAGS += -g
>    CXXFLAGS += -g
> -- 
> 2.46.0
>