LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Joao Pinto <Joao.Pinto@synopsys.com>
To: Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
	<bhelgaas@google.com>, <lorenzo.pieralisi@arm.com>,
	<Joao.Pinto@synopsys.com>, <jingoohan1@gmail.com>,
	<kishon@ti.com>, <robh+dt@kernel.org>, <mark.rutland@arm.com>
Cc: <linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<devicetree@vger.kernel.org>
Subject: Re: [PATCH v5 09/10] PCI: dwc: Small computation improvement
Date: Tue, 17 Apr 2018 20:05:11 +0100	[thread overview]
Message-ID: <d0a96713-9e34-2351-4301-8a2f9039e224@synopsys.com> (raw)
In-Reply-To: <4fc069a2b82cc7a3790bc528a6b67636654a3a35.1523973931.git.gustavo.pimentel@synopsys.com>

Às 3:34 PM de 4/17/2018, Gustavo Pimentel escreveu:
> Replaces a simple division by 2 to a right shift rotation of 1 bit.
> 
> Probably any recent and decent compiler does this kind of substitution
> in order to improve code performance. Nevertheless it's a coding good
> practice whenever there is a division / multiplication by multiple of 2
> to replace it by the equivalent operation in this case, the shift
> rotation.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> ---
> Change v1->v2:
>  - Nothing changed, just to follow the patch set version.
> Change v2->v3:
>  - Nothing changed, just to follow the patch set version.
> Changes v3->v4:
>  - Added a small explication to the log description.
> Changes v4->v5:
>  - Nothing changed, just to follow the patch set version.
> 
>  drivers/pci/dwc/pcie-designware-host.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c
> index 5a23f78..fc55fde 100644
> --- a/drivers/pci/dwc/pcie-designware-host.c
> +++ b/drivers/pci/dwc/pcie-designware-host.c
> @@ -332,8 +332,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  
>  	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
>  	if (cfg_res) {
> -		pp->cfg0_size = resource_size(cfg_res) / 2;
> -		pp->cfg1_size = resource_size(cfg_res) / 2;
> +		pp->cfg0_size = resource_size(cfg_res) >> 1;
> +		pp->cfg1_size = resource_size(cfg_res) >> 1;
>  		pp->cfg0_base = cfg_res->start;
>  		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
>  	} else if (!pp->va_cfg0_base) {
> @@ -377,8 +377,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  			break;
>  		case 0:
>  			pp->cfg = win->res;
> -			pp->cfg0_size = resource_size(pp->cfg) / 2;
> -			pp->cfg1_size = resource_size(pp->cfg) / 2;
> +			pp->cfg0_size = resource_size(pp->cfg) >> 1;
> +			pp->cfg1_size = resource_size(pp->cfg) >> 1;
>  			pp->cfg0_base = pp->cfg->start;
>  			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
>  			break;
> 

Thanks Gustavo!

Acked-by: Joao Pinto <jpinto@synopsys.com>

  parent reply	other threads:[~2018-04-17 19:05 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-17 14:34 [PATCH v5 00/10] Designware EP support and code clean up Gustavo Pimentel
2018-04-17 14:34 ` [PATCH v5 01/10] bindings: PCI: designware: Example update Gustavo Pimentel
2018-04-18 14:05   ` Rob Herring
2018-04-17 14:34 ` [PATCH v5 02/10] PCI: dwc: Add support for endpoint mode Gustavo Pimentel
2018-04-17 18:46   ` Joao Pinto
2018-04-17 14:34 ` [PATCH v5 03/10] PCI: endpoint: functions/pci-epf-test: Add second entry Gustavo Pimentel
2018-04-18 14:03   ` kbuild test robot
2018-04-17 14:34 ` [PATCH v5 04/10] bindings: PCI: designware: Add support for the EP in Designware driver Gustavo Pimentel
2018-04-17 14:34 ` [PATCH v5 05/10] PCI: Adds device ID for Synopsys Sample Endpoint Gustavo Pimentel
2018-04-18 13:40   ` Bjorn Helgaas
2018-04-17 14:34 ` [PATCH v5 06/10] misc: pci_endpoint_test: Add designware EP entry Gustavo Pimentel
2018-04-17 14:34 ` [PATCH v5 07/10] PCI: dwc: Define maximum number of vectors Gustavo Pimentel
2018-04-17 18:56   ` Joao Pinto
2018-04-17 14:34 ` [PATCH v5 08/10] PCI: dwc: Replace lower into upper case characters Gustavo Pimentel
2018-04-17 19:01   ` Joao Pinto
2018-04-17 14:34 ` [PATCH v5 09/10] PCI: dwc: Small computation improvement Gustavo Pimentel
2018-04-17 14:37   ` Jingoo Han
2018-04-17 19:05   ` Joao Pinto [this message]
2018-04-17 14:34 ` [PATCH v5 10/10] PCI: dwc: Replace magic number by defines Gustavo Pimentel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d0a96713-9e34-2351-4301-8a2f9039e224@synopsys.com \
    --to=joao.pinto@synopsys.com \
    --cc=bhelgaas@google.com \
    --cc=devicetree@vger.kernel.org \
    --cc=gustavo.pimentel@synopsys.com \
    --cc=jingoohan1@gmail.com \
    --cc=kishon@ti.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --subject='Re: [PATCH v5 09/10] PCI: dwc: Small computation improvement' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).