ArmPkg/CompilerIntrinsicesLib: Fixed memmove() and memset()

- Fixed memmove when going backward: the copy started one byte
  after the end of the region to copy
- memset: - removed unused register
          - fixed arguments size and character arguments were
            actually reversed
- Added memmove() to ARM32 GCC

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16328 6f19259b-4bc3-4df7-8a09-765794883524

ArmPkg/Library/CompilerIntrinsicsLib/Arm/memmove.S

@@ -0,0 +1,48 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2011-2014, ARM Limited. All rights reserved.
+#
+# This program and the accompanying materials
+# are licensed and made available under the terms and conditions of the BSD License
+# which accompanies this distribution.  The full text of the license may be found at
+# http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#------------------------------------------------------------------------------
+
+  .text
+  .align 2
+  GCC_ASM_EXPORT (memmove)
+
+# VOID
+# EFIAPI
+# memmove (
+#  IN  VOID          *Destination,
+#  IN  CONST VOID    *Source,
+#  IN  UINT32        Size
+#  );
+ASM_PFX(memmove):
+  CMP     r2, #0
+  BXEQ    lr
+  CMP     r0, r1
+  BXEQ    lr
+  BHI     memmove_backward
+
+memmove_forward:
+  LDRB    r3, [r1], #1
+  STRB    r3, [r0], #1
+  SUBS    r2, r2, #1
+  BXEQ    lr
+  B       memmove_forward
+
+memmove_backward:
+  add     r0, r2
+  add     r1, r2
+memmove_backward_loop:
+  LDRB    r3, [r1, #-1]!
+  STRB    r3, [r0, #-1]!
+  SUBS    r2, r2, #1
+  BXEQ    lr
+  B       memmove_backward_loop