-#------------------------------------------------------------------------------ \r
+#------------------------------------------------------------------------------\r
#\r
# CopyMem() worker for ARM\r
#\r
# This file started out as C code that did 64 bit moves if the buffer was\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
+# 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
# This program and the accompanying materials\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
**/\r
.text\r
.align 2\r
-.globl ASM_PFX(InternalMemCopyMem)\r
-INTERWORK_FUNC(InternalMemCopyMem)\r
+GCC_ASM_EXPORT(InternalMemCopyMem)\r
\r
ASM_PFX(InternalMemCopyMem):\r
- stmfd sp!, {r4-r11, lr}\r
- tst r0, #3\r
- mov r11, r0\r
- mov r10, r0\r
- mov ip, r2\r
- mov lr, r1\r
- movne r0, #0\r
- bne L4\r
- tst r1, #3\r
- movne r3, #0\r
- moveq r3, #1\r
- cmp r2, #31\r
- movls r0, #0\r
- andhi r0, r3, #1\r
-L4:\r
- cmp r11, r1\r
- bcc L26\r
- bls L7\r
- rsb r3, r1, r11\r
- cmp ip, r3\r
- bcc L26\r
- cmp ip, #0\r
- beq L7\r
- add r10, r11, ip\r
- add lr, ip, r1\r
- b L16\r
-L29:\r
- sub ip, ip, #8\r
- cmp ip, #7\r
- ldrd r2, [lr, #-8]!\r
- movls r0, #0\r
- cmp ip, #0\r
- strd r2, [r10, #-8]!\r
- beq L7\r
-L16:\r
- cmp r0, #0\r
- bne L29\r
- sub r3, lr, #1\r
- sub ip, ip, #1\r
- ldrb r3, [r3, #0] \r
- sub r2, r10, #1\r
- cmp ip, #0\r
- sub r10, r10, #1\r
- sub lr, lr, #1\r
- strb r3, [r2, #0]\r
- bne L16\r
- b L7\r
-L11:\r
- ldrb r3, [lr], #1 \r
- sub ip, ip, #1\r
- strb r3, [r10], #1\r
-L26:\r
- cmp ip, #0\r
- beq L7\r
-L30:\r
- cmp r0, #0\r
- beq L11\r
- sub ip, ip, #32\r
- cmp ip, #31\r
- ldmia lr!, {r2-r9}\r
- movls r0, #0\r
- cmp ip, #0\r
- stmia r10!, {r2-r9}\r
- bne L30\r
-L7:\r
- mov r0, r11\r
- ldmfd sp!, {r4-r11, pc}\r
- \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
projects / mirror_edk2.git / blobdiff