1 files changed, 84 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm b/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm
new file mode 100644
index 0000000000..2a8dc7d019
--- /dev/null
+++ b/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm
@@ -0,0 +1,84 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
+;
+; 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.
+;
+;------------------------------------------------------------------------------
+
+    EXPORT  InternalMemZeroMem
+    EXPORT  InternalMemSetMem
+    EXPORT  InternalMemSetMem16
+    EXPORT  InternalMemSetMem32
+    EXPORT  InternalMemSetMem64
+
+    AREA    SetMem, CODE, READONLY, CODEALIGN, ALIGN=5
+    THUMB
+
+InternalMemZeroMem
+    movs    r2, #0
+
+InternalMemSetMem
+    uxtb    r2, r2
+    orr     r2, r2, r2, lsl #8
+
+InternalMemSetMem16
+    uxth    r2, r2
+    orr     r2, r2, r2, lsr #16
+
+InternalMemSetMem32
+    mov     r3, r2
+
+InternalMemSetMem64
+    push    {r4, lr}
+    cmp     r1, #16                 ; fewer than 16 bytes of input?
+    add     r1, r1, r0              ; r1 := dst + length
+    add     lr, r0, #16
+    blt     L2
+    bic     lr, lr, #15             ; align output pointer
+
+    str     r2, [r0]                ; potentially unaligned store of 4 bytes
+    str     r3, [r0, #4]            ; potentially unaligned store of 4 bytes
+    str     r2, [r0, #8]            ; potentially unaligned store of 4 bytes
+    str     r3, [r0, #12]           ; potentially unaligned store of 4 bytes
+    beq     L1
+
+L0
+    add     lr, lr, #16             ; advance the output pointer by 16 bytes
+    subs    r4, r1, lr              ; past the output?
+    blt     L3                      ; break out of the loop
+    strd    r2, r3, [lr, #-16]      ; aligned store of 16 bytes
+    strd    r2, r3, [lr, #-8]
+    bne     L0                      ; goto beginning of loop
+L1
+    pop     {r4, pc}
+
+L2
+    subs    r4, r1, lr
+L3
+    adds    r4, r4, #16
+    subs    r1, r1, #8
+    cmp     r4, #4                  ; between 4 and 15 bytes?
+    blt     L4
+    cmp     r4, #8                  ; between 8 and 15 bytes?
+    str     r2, [lr, #-16]          ; overlapping store of 4 + (4 + 4) + 4 bytes
+    itt     gt
+    strgt   r3, [lr, #-12]
+    strgt   r2, [r1]
+    str     r3, [r1, #4]
+    pop     {r4, pc}
+
+L4
+    cmp     r4, #2                  ; 2 or 3 bytes?
+    strb    r2, [lr, #-16]          ; store 1 byte
+    it      ge
+    strhge  r2, [r1, #6]            ; store 2 bytes
+    pop     {r4, pc}
+
+    END