From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755292AbbAWLHs (ORCPT ); Fri, 23 Jan 2015 06:07:48 -0500 Received: from mail-lb0-f172.google.com ([209.85.217.172]:50874 "EHLO mail-lb0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753141AbbAWLHr (ORCPT ); Fri, 23 Jan 2015 06:07:47 -0500 From: Rasmus Villemoes To: Jay Cliburn , Chris Snook Cc: Rasmus Villemoes , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] atheros/atlx: Simplify bit manipulations Date: Fri, 23 Jan 2015 12:06:52 +0100 Message-Id: <1422011212-30095-1-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The code 'if (foo & X) foo &= ~X;' is semantically equivalent to simply 'foo &= ~X;', but gcc generates about four instructions for the former, one for the latter. Similarly, if X consists of a single bit, 'if (!(foo & X)) X |= X;' can be replaced by 'foo |= X;'. In the atl2 case, gcc does know how to merge the new adjacent operations, so altogether this gives a nice little code size reduction of about 80 bytes. Signed-off-by: Rasmus Villemoes --- drivers/net/ethernet/atheros/atlx/atl1.c | 3 +-- drivers/net/ethernet/atheros/atlx/atl2.c | 12 ++++-------- 2 files changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c index 2c8f398aeda9..d9d61d6e8386 100644 --- a/drivers/net/ethernet/atheros/atlx/atl1.c +++ b/drivers/net/ethernet/atheros/atlx/atl1.c @@ -1667,8 +1667,7 @@ static void atl1_via_workaround(struct atl1_adapter *adapter) unsigned long value; value = ioread16(adapter->hw.hw_addr + PCI_COMMAND); - if (value & PCI_COMMAND_INTX_DISABLE) - value &= ~PCI_COMMAND_INTX_DISABLE; + value &= ~PCI_COMMAND_INTX_DISABLE; iowrite32(value, adapter->hw.hw_addr + PCI_COMMAND); } diff --git a/drivers/net/ethernet/atheros/atlx/atl2.c b/drivers/net/ethernet/atheros/atlx/atl2.c index 84a09e8ddd9c..46d1b959daa8 100644 --- a/drivers/net/ethernet/atheros/atlx/atl2.c +++ b/drivers/net/ethernet/atheros/atlx/atl2.c @@ -1278,14 +1278,10 @@ static void atl2_setup_pcicmd(struct pci_dev *pdev) pci_read_config_word(pdev, PCI_COMMAND, &cmd); - if (cmd & PCI_COMMAND_INTX_DISABLE) - cmd &= ~PCI_COMMAND_INTX_DISABLE; - if (cmd & PCI_COMMAND_IO) - cmd &= ~PCI_COMMAND_IO; - if (0 == (cmd & PCI_COMMAND_MEMORY)) - cmd |= PCI_COMMAND_MEMORY; - if (0 == (cmd & PCI_COMMAND_MASTER)) - cmd |= PCI_COMMAND_MASTER; + cmd &= ~PCI_COMMAND_INTX_DISABLE; + cmd &= ~PCI_COMMAND_IO; + cmd |= PCI_COMMAND_MEMORY; + cmd |= PCI_COMMAND_MASTER; pci_write_config_word(pdev, PCI_COMMAND, cmd); /* -- 2.1.3