ArmPkg/Library/CompilerIntrinsicsLib/Arm/memmove.S

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  14
  15   .text
  16   .align 2
  17   GCC_ASM_EXPORT (memmove)
  18
  19 # VOID
  20 # EFIAPI
  21 # memmove (
  22 #  IN  VOID          *Destination,
  23 #  IN  CONST VOID    *Source,
  24 #  IN  UINT32        Size
  25 #  );
  26 ASM_PFX(memmove):
  27   CMP     r2, #0
  28   BXEQ    lr
  29   CMP     r0, r1
  30   BXEQ    lr
  31   BHI     memmove_backward
  32
  33 memmove_forward:
  34   LDRB    r3, [r1], #1
  35   STRB    r3, [r0], #1
  36   SUBS    r2, r2, #1
  37   BXEQ    lr
  38   B       memmove_forward
  39
  40 memmove_backward:
  41   add     r0, r2
  42   add     r1, r2
  43 memmove_backward_loop:
  44   LDRB    r3, [r1, #-1]!
  45   STRB    r3, [r0, #-1]!
  46   SUBS    r2, r2, #1
  47   BXEQ    lr
  48   B       memmove_backward_loop