ArmPkg/Library/CompilerIntrinsicsLib/Arm/clzsi2.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   4 #
   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         .text
  16         .align 2
  17         GCC_ASM_EXPORT(__clzsi2)
  18
  19 ASM_PFX(__clzsi2):
  20         @ frame_needed = 1, uses_anonymous_args = 0
  21         stmfd   sp!, {r7, lr}
  22         add     r7, sp, #0
  23         movs    r3, r0, lsr #16
  24         movne   r3, #16
  25         moveq   r3, #0
  26         movne   r9, #0
  27         moveq   r9, #16
  28         mov     r3, r0, lsr r3
  29         tst     r3, #65280
  30         movne   r0, #8
  31         moveq   r0, #0
  32         movne   lr, #0
  33         moveq   lr, #8
  34         mov     r3, r3, lsr r0
  35         tst     r3, #240
  36         movne   r0, #4
  37         moveq   r0, #0
  38         movne   ip, #0
  39         moveq   ip, #4
  40         mov     r3, r3, lsr r0
  41         tst     r3, #12
  42         movne   r0, #2
  43         moveq   r0, #0
  44         movne   r1, #0
  45         moveq   r1, #2
  46         mov     r2, r3, lsr r0
  47         add     r3, lr, r9
  48         add     r0, r3, ip
  49         add     r1, r0, r1
  50         mov     r0, r2, lsr #1
  51         eor     r0, r0, #1
  52         ands    r0, r0, #1
  53         mvnne   r0, #0
  54         rsb     r3, r2, #2
  55         and     r0, r0, r3
  56         add     r0, r1, r0
  57         ldmfd   sp!, {r7, pc}