From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758111AbeD0MBn (ORCPT ); Fri, 27 Apr 2018 08:01:43 -0400 Received: from smtprelay6.synopsys.com ([198.182.37.59]:36058 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757661AbeD0MAO (ORCPT ); Fri, 27 Apr 2018 08:00:14 -0400 From: Gustavo Pimentel To: 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, gustavo.pimentel@synopsys.com Subject: [PATCH v8 8/9] PCI: dwc: Small computation improvement Date: Fri, 27 Apr 2018 13:00:03 +0100 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace a division by 2 operation for 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 Acked-by: Jingoo Han Acked-by: Joao Pinto --- 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. Changes v5->v6: - Nothing changed, just to follow the patch set version. Changes v6->v7: - Nothing changed, just to follow the patch set version. Changes v7->v8: - Patch description rework for an imperative verbal mode. 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; -- 2.7.4