ArmPkg/Library/CompilerIntrinsicsLib/Arm/clzsi2.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   4 #
   5 # SPDX-License-Identifier: BSD-2-Clause-Patent
   6 #
   7 #------------------------------------------------------------------------------
   8
   9 #include <AsmMacroIoLib.h>
  10
  11 ASM_FUNC(__clzsi2)
  12   @ frame_needed = 1, uses_anonymous_args = 0
  13   stmfd  sp!, {r7, lr}
  14   add  r7, sp, #0
  15   movs  r3, r0, lsr #16
  16   movne  r3, #16
  17   moveq  r3, #0
  18   movne  r9, #0
  19   moveq  r9, #16
  20   mov  r3, r0, lsr r3
  21   tst  r3, #65280
  22   movne  r0, #8
  23   moveq  r0, #0
  24   movne  lr, #0
  25   moveq  lr, #8
  26   mov  r3, r3, lsr r0
  27   tst  r3, #240
  28   movne  r0, #4
  29   moveq  r0, #0
  30   movne  ip, #0
  31   moveq  ip, #4
  32   mov  r3, r3, lsr r0
  33   tst  r3, #12
  34   movne  r0, #2
  35   moveq  r0, #0
  36   movne  r1, #0
  37   moveq  r1, #2
  38   mov  r2, r3, lsr r0
  39   add  r3, lr, r9
  40   add  r0, r3, ip
  41   add  r1, r0, r1
  42   mov  r0, r2, lsr #1
  43   eor  r0, r0, #1
  44   ands  r0, r0, #1
  45   mvnne  r0, #0
  46   rsb  r3, r2, #2
  47   and  r0, r0, r3
  48   add  r0, r1, r0
  49   ldmfd  sp!, {r7, pc}