ArmPkg/Library/CompilerIntrinsicsLib/Arm/switchu8.S

   1 #/** @file
   2 #  Compiler intrinsic for ARM compiler
   3 #
   4 #  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   5 #  This program and the accompanying materials
   6 #  are licensed and made available under the terms and conditions of the BSD License
   7 #  which accompanies this distribution.  The full text of the license may be found at
   8 #  http)://opensource.org/licenses/bsd-license.php
   9 #
  10 #  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 #  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.;
  12 #
  13 #**/
  14 #
  15
  16 #include <AsmMacroIoLib.h>
  17
  18 .syntax unified
  19
  20 ASM_FUNC(__switchu8)
  21     ldrb      ip,[lr,#-1]
  22     cmp       r0,ip
  23     ldrbcc    r0,[lr,r0]
  24     ldrbcs    r0,[lr,ip]
  25     add       ip,lr,r0,LSL #1
  26     bx        ip
  27