Re: [PATCH] x86: squash lines for simple wrapper functions

From: Ingo Molnar <mingo@kernel.org>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: x86@kernel.org, Ingo Molnar <mingo@redhat.com>,
	Toshi Kani <toshi.kani@hpe.com>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Borislav Petkov <bp@suse.de>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Nathan Zimmer <nzimmer@sgi.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, Mike Travis <travis@sgi.com>,
	Daniel J Blueman <daniel@numascale.com>,
	Dimitri Sivanich <sivanich@sgi.com>,
	Matt Fleming <matt@codeblueprint.co.uk>,
	Hedi Berriche <hedi@sgi.com>, Steffen Persvold <sp@numascale.com>,
	Alex Thorlton <athorlton@sgi.com>,
	Wei Jiangang <weijg.fnst@cn.fujitsu.com>
Subject: Re: [PATCH] x86: squash lines for simple wrapper functions
Date: Thu, 8 Sep 2016 08:33:59 +0200	[thread overview]
Message-ID: <20160908063359.GB24253@gmail.com> (raw)
In-Reply-To: <1473161053-10068-1-git-send-email-yamada.masahiro@socionext.com>

* Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Remove unneeded variables and assignments.  I am also removing
> unnecessary parentheses while I am here.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
>  arch/x86/kernel/apic/apic_flat_64.c  | 16 +++-------------
>  arch/x86/kernel/apic/apic_numachip.c |  5 +----
>  arch/x86/kernel/apic/x2apic_uv_x.c   |  5 +----
>  arch/x86/mm/pat_rbtree.c             |  4 +---
>  arch/x86/platform/uv/bios_uv.c       |  7 ++-----
>  arch/x86/platform/uv/tlb_uv.c        |  6 +-----
>  6 files changed, 9 insertions(+), 34 deletions(-)
> 
> diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
> index 5b2ae10..c7228f9 100644
> --- a/arch/x86/kernel/apic/apic_flat_64.c
> +++ b/arch/x86/kernel/apic/apic_flat_64.c
> @@ -116,27 +116,17 @@ static void flat_send_IPI_all(int vector)
>  
>  static unsigned int flat_get_apic_id(unsigned long x)
>  {
> -	unsigned int id;
> -
> -	id = (((x)>>24) & 0xFFu);
> -
> -	return id;
> +	return ((x) >> 24) & 0xFFu;

So while we are removing unnecessary things, exactly why does the 'x' need 
parentheses?

>  static unsigned long set_apic_id(unsigned int id)
>  {
> -	unsigned long x;
> -
> -	x = ((id & 0xFFu)<<24);
> -	return x;
> +	return (id & 0xFFu) << 24;

'id' is already unsigned, why does the 'u' have to be stressed in the literal? 
(Ditto for other places as well)

>  static unsigned long numachip1_set_apic_id(unsigned int id)
>  {
> -	unsigned long x;
> -
> -	x = ((id & 0xffU) << 24);
> -	return x;
> +	return (id & 0xffU) << 24;
>  }

Why is the spelling of the literal inconsistent here with the other patterns?

> +++ b/arch/x86/kernel/apic/x2apic_uv_x.c
> @@ -533,11 +533,8 @@ static unsigned int x2apic_get_apic_id(unsigned long x)
>  
>  static unsigned long set_apic_id(unsigned int id)
>  {
> -	unsigned long x;
> -
>  	/* maskout x2apic_extra_bits ? */
> -	x = id;
> -	return x;
> +	return id;
>  }

This was clearly left there to document a quirk and as a placeholder for future 
changes.

Thanks,

	Ingo