-;------------------------------------------------------------------------------ \r
+;------------------------------------------------------------------------------\r
;\r
; CopyMem() worker for ARM\r
;\r
; 32-bit aligned, else it does a byte copy. It also does a byte copy for\r
; any trailing bytes. It was updated to do 32-byte copies using stm/ldm.\r
;\r
-; Copyright (c) 2008-2010 Apple Inc. All rights reserved.<BR>\r
-; All rights reserved. This program and the accompanying materials\r
+; Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>\r
+; This program and the accompanying materials\r
; are licensed and made available under the terms and conditions of the BSD License\r
; which accompanies this distribution. The full text of the license may be found at\r
; http://opensource.org/licenses/bsd-license.php\r
/**\r
Copy Length bytes from Source to Destination. Overlap is OK.\r
\r
- This implementation \r
+ This implementation\r
\r
@param Destination Target of copy\r
@param Source Place to copy from\r
IN UINTN Length\r
)\r
**/\r
- EXPORT InternalMemCopyMem\r
-
- AREA AsmMemStuff, CODE, READONLY
-\r
-InternalMemCopyMem\r
- stmfd sp!, {r4-r11, lr}
- tst r0, #3
- mov r11, r0
- mov r10, r0
- mov ip, r2
- mov lr, r1
- movne r0, #0
- bne L4
- tst r1, #3
- movne r3, #0
- moveq r3, #1
- cmp r2, #31
- movls r0, #0
- andhi r0, r3, #1
-L4
- cmp r11, r1
- bcc L26
- bls L7
- rsb r3, r1, r11
- cmp ip, r3
- bcc L26
- cmp ip, #0
- beq L7
- add r10, r11, ip
- add lr, ip, r1
- b L16
-L29
- sub ip, ip, #8
- cmp ip, #7
- ldrd r2, [lr, #-8]!
- movls r0, #0
- cmp ip, #0
- strd r2, [r10, #-8]!
- beq L7
-L16
- cmp r0, #0
- bne L29
- sub r3, lr, #1
- sub ip, ip, #1
- ldrb r3, [r3, #0]
- sub r2, r10, #1
- cmp ip, #0
- sub r10, r10, #1
- sub lr, lr, #1
- strb r3, [r2, #0]
- bne L16
- b L7
-L11
- ldrb r3, [lr], #1
- sub ip, ip, #1
- strb r3, [r10], #1
-L26
- cmp ip, #0
- beq L7
-L30
- cmp r0, #0
- beq L11
- sub ip, ip, #32
- cmp ip, #31
- ldmia lr!, {r2-r9}
- movls r0, #0
- cmp ip, #0
- stmia r10!, {r2-r9}
- bne L30
-L7
- mov r0, r11
- ldmfd sp!, {r4-r11, pc}\r
- \r
+\r
+ INCLUDE AsmMacroExport.inc\r
+\r
+ RVCT_ASM_EXPORT InternalMemCopyMem\r
+ stmfd sp!, {r4-r11, lr}\r
+ // Save the input parameters in extra registers (r11 = destination, r14 = source, r12 = length)\r
+ mov r11, r0\r
+ mov r10, r0\r
+ mov r12, r2\r
+ mov r14, r1\r
+\r
+memcopy_check_overlapped\r
+ cmp r11, r1\r
+ // If (dest < source)\r
+ bcc memcopy_check_optim_default\r
+ // If (dest <= source). But with the previous condition -> If (dest == source)\r
+ bls memcopy_end\r
+\r
+ // If (source + length < dest)\r
+ rsb r3, r1, r11\r
+ cmp r12, r3\r
+ bcc memcopy_check_optim_default\r
+\r
+ // If (length == 0)\r
+ cmp r12, #0\r
+ beq memcopy_end\r
+\r
+ b memcopy_check_optim_overlap\r
+\r
+memcopy_check_optim_default\r
+ // Check if we can use an optimized path ((length >= 32) && destination word-aligned && source word-aligned) for the memcopy (optimized path if r0 == 1)\r
+ tst r0, #0xF\r
+ movne r0, #0\r
+ bne memcopy_default\r
+ tst r1, #0xF\r
+ movne r3, #0\r
+ moveq r3, #1\r
+ cmp r2, #31\r
+ movls r0, #0\r
+ andhi r0, r3, #1\r
+ b memcopy_default\r
+\r
+memcopy_check_optim_overlap\r
+ // r10 = dest_end, r14 = source_end\r
+ add r10, r11, r12\r
+ add r14, r12, r1\r
+\r
+ // Are we in the optimized case ((length >= 32) && dest_end word-aligned && source_end word-aligned)\r
+ cmp r2, #31\r
+ movls r0, #0\r
+ movhi r0, #1\r
+ tst r10, #0xF\r
+ movne r0, #0\r
+ tst r14, #0xF\r
+ movne r0, #0\r
+ b memcopy_overlapped\r
+\r
+memcopy_overlapped_non_optim\r
+ // We read 1 byte from the end of the source buffer\r
+ sub r3, r14, #1\r
+ sub r12, r12, #1\r
+ ldrb r3, [r3, #0]\r
+ sub r2, r10, #1\r
+ cmp r12, #0\r
+ // We write 1 byte at the end of the dest buffer\r
+ sub r10, r10, #1\r
+ sub r14, r14, #1\r
+ strb r3, [r2, #0]\r
+ bne memcopy_overlapped_non_optim\r
+ b memcopy_end\r
+\r
+// r10 = dest_end, r14 = source_end\r
+memcopy_overlapped\r
+ // Are we in the optimized case ?\r
+ cmp r0, #0\r
+ beq memcopy_overlapped_non_optim\r
+\r
+ // Optimized Overlapped - Read 32 bytes\r
+ sub r14, r14, #32\r
+ sub r12, r12, #32\r
+ cmp r12, #31\r
+ ldmia r14, {r2-r9}\r
+\r
+ // If length is less than 32 then disable optim\r
+ movls r0, #0\r
+\r
+ cmp r12, #0\r
+\r
+ // Optimized Overlapped - Write 32 bytes\r
+ sub r10, r10, #32\r
+ stmia r10, {r2-r9}\r
+\r
+ // while (length != 0)\r
+ bne memcopy_overlapped\r
+ b memcopy_end\r
+\r
+memcopy_default_non_optim\r
+ // Byte copy\r
+ ldrb r3, [r14], #1\r
+ sub r12, r12, #1\r
+ strb r3, [r10], #1\r
+\r
+memcopy_default\r
+ cmp r12, #0\r
+ beq memcopy_end\r
+\r
+// r10 = dest, r14 = source\r
+memcopy_default_loop\r
+ cmp r0, #0\r
+ beq memcopy_default_non_optim\r
+\r
+ // Optimized memcopy - Read 32 Bytes\r
+ sub r12, r12, #32\r
+ cmp r12, #31\r
+ ldmia r14!, {r2-r9}\r
+\r
+ // If length is less than 32 then disable optim\r
+ movls r0, #0\r
+\r
+ cmp r12, #0\r
+\r
+ // Optimized memcopy - Write 32 Bytes\r
+ stmia r10!, {r2-r9}\r
+\r
+ // while (length != 0)\r
+ bne memcopy_default_loop\r
+\r
+memcopy_end\r
+ mov r0, r11\r
+ ldmfd sp!, {r4-r11, pc}\r
+\r
END\r
- \r
+\r
projects / mirror_edk2.git / blobdiff