diff options
Diffstat (limited to 'Core/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm')
-rw-r--r-- | Core/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm b/Core/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm new file mode 100644 index 0000000000..c2e2842a63 --- /dev/null +++ b/Core/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.asm @@ -0,0 +1,96 @@ +;------------------------------------------------------------------------------
+;
+; 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
+
+InternalMemSetMem16
+ uxth r2, r2
+ lsl r1, r1, #1
+ orr r2, r2, r2, lsl #16
+ b B0
+
+InternalMemSetMem32
+ lsl r1, r1, #2
+ b B0
+
+InternalMemSetMem64
+ lsl r1, r1, #3
+ b B1
+
+ ALIGN 32
+InternalMemSetMem
+ uxtb r2, r2
+ orr r2, r2, r2, lsl #8
+ orr r2, r2, r2, lsl #16
+ b B0
+
+InternalMemZeroMem
+ movs r2, #0
+B0
+ mov r3, r2
+
+B1
+ 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
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