185 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			185 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * String handling functions.
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|  *
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|  * Copyright IBM Corp. 2012
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|  */
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| 
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| #include <linux/linkage.h>
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| #include <asm/export.h>
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| #include <asm/nospec-insn.h>
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| 
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| 	GEN_BR_THUNK %r14
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| 
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| /*
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|  * void *memmove(void *dest, const void *src, size_t n)
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|  */
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| ENTRY(memmove)
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| 	ltgr	%r4,%r4
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| 	lgr	%r1,%r2
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| 	jz	.Lmemmove_exit
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| 	aghi	%r4,-1
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| 	clgr	%r2,%r3
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| 	jnh	.Lmemmove_forward
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| 	la	%r5,1(%r4,%r3)
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| 	clgr	%r2,%r5
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| 	jl	.Lmemmove_reverse
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| .Lmemmove_forward:
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| 	srlg	%r0,%r4,8
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| 	ltgr	%r0,%r0
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| 	jz	.Lmemmove_forward_remainder
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| .Lmemmove_forward_loop:
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| 	mvc	0(256,%r1),0(%r3)
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| 	la	%r1,256(%r1)
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| 	la	%r3,256(%r3)
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| 	brctg	%r0,.Lmemmove_forward_loop
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| .Lmemmove_forward_remainder:
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| 	larl	%r5,.Lmemmove_mvc
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| 	ex	%r4,0(%r5)
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| .Lmemmove_exit:
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| 	BR_EX	%r14
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| .Lmemmove_reverse:
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| 	ic	%r0,0(%r4,%r3)
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| 	stc	%r0,0(%r4,%r1)
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| 	brctg	%r4,.Lmemmove_reverse
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| 	ic	%r0,0(%r4,%r3)
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| 	stc	%r0,0(%r4,%r1)
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| 	BR_EX	%r14
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| .Lmemmove_mvc:
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| 	mvc	0(1,%r1),0(%r3)
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| EXPORT_SYMBOL(memmove)
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| 
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| /*
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|  * memset implementation
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|  *
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|  * This code corresponds to the C construct below. We do distinguish
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|  * between clearing (c == 0) and setting a memory array (c != 0) simply
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|  * because nearly all memset invocations in the kernel clear memory and
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|  * the xc instruction is preferred in such cases.
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|  *
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|  * void *memset(void *s, int c, size_t n)
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|  * {
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|  *	if (likely(c == 0))
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|  *		return __builtin_memset(s, 0, n);
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|  *	return __builtin_memset(s, c, n);
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|  * }
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|  */
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| ENTRY(memset)
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| 	ltgr	%r4,%r4
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| 	jz	.Lmemset_exit
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| 	ltgr	%r3,%r3
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| 	jnz	.Lmemset_fill
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| 	aghi	%r4,-1
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| 	srlg	%r3,%r4,8
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| 	ltgr	%r3,%r3
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| 	lgr	%r1,%r2
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| 	jz	.Lmemset_clear_remainder
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| .Lmemset_clear_loop:
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| 	xc	0(256,%r1),0(%r1)
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| 	la	%r1,256(%r1)
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| 	brctg	%r3,.Lmemset_clear_loop
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| .Lmemset_clear_remainder:
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| 	larl	%r3,.Lmemset_xc
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| 	ex	%r4,0(%r3)
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| .Lmemset_exit:
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| 	BR_EX	%r14
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| .Lmemset_fill:
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| 	cghi	%r4,1
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| 	lgr	%r1,%r2
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| 	je	.Lmemset_fill_exit
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| 	aghi	%r4,-2
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| 	srlg	%r5,%r4,8
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| 	ltgr	%r5,%r5
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| 	jz	.Lmemset_fill_remainder
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| .Lmemset_fill_loop:
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| 	stc	%r3,0(%r1)
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| 	mvc	1(255,%r1),0(%r1)
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| 	la	%r1,256(%r1)
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| 	brctg	%r5,.Lmemset_fill_loop
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| .Lmemset_fill_remainder:
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| 	stc	%r3,0(%r1)
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| 	larl	%r5,.Lmemset_mvc
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| 	ex	%r4,0(%r5)
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| 	BR_EX	%r14
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| .Lmemset_fill_exit:
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| 	stc	%r3,0(%r1)
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| 	BR_EX	%r14
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| .Lmemset_xc:
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| 	xc	0(1,%r1),0(%r1)
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| .Lmemset_mvc:
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| 	mvc	1(1,%r1),0(%r1)
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| EXPORT_SYMBOL(memset)
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| 
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| /*
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|  * memcpy implementation
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|  *
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|  * void *memcpy(void *dest, const void *src, size_t n)
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|  */
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| ENTRY(memcpy)
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| 	ltgr	%r4,%r4
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| 	jz	.Lmemcpy_exit
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| 	aghi	%r4,-1
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| 	srlg	%r5,%r4,8
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| 	ltgr	%r5,%r5
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| 	lgr	%r1,%r2
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| 	jnz	.Lmemcpy_loop
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| .Lmemcpy_remainder:
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| 	larl	%r5,.Lmemcpy_mvc
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| 	ex	%r4,0(%r5)
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| .Lmemcpy_exit:
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| 	BR_EX	%r14
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| .Lmemcpy_loop:
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| 	mvc	0(256,%r1),0(%r3)
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| 	la	%r1,256(%r1)
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| 	la	%r3,256(%r3)
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| 	brctg	%r5,.Lmemcpy_loop
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| 	j	.Lmemcpy_remainder
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| .Lmemcpy_mvc:
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| 	mvc	0(1,%r1),0(%r3)
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| EXPORT_SYMBOL(memcpy)
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| 
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| /*
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|  * __memset16/32/64
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|  *
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|  * void *__memset16(uint16_t *s, uint16_t v, size_t count)
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|  * void *__memset32(uint32_t *s, uint32_t v, size_t count)
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|  * void *__memset64(uint64_t *s, uint64_t v, size_t count)
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|  */
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| .macro __MEMSET bits,bytes,insn
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| ENTRY(__memset\bits)
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| 	ltgr	%r4,%r4
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| 	jz	.L__memset_exit\bits
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| 	cghi	%r4,\bytes
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| 	je	.L__memset_store\bits
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| 	aghi	%r4,-(\bytes+1)
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| 	srlg	%r5,%r4,8
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| 	ltgr	%r5,%r5
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| 	lgr	%r1,%r2
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| 	jz	.L__memset_remainder\bits
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| .L__memset_loop\bits:
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| 	\insn	%r3,0(%r1)
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| 	mvc	\bytes(256-\bytes,%r1),0(%r1)
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| 	la	%r1,256(%r1)
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| 	brctg	%r5,.L__memset_loop\bits
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| .L__memset_remainder\bits:
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| 	\insn	%r3,0(%r1)
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| 	larl	%r5,.L__memset_mvc\bits
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| 	ex	%r4,0(%r5)
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| 	BR_EX	%r14
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| .L__memset_store\bits:
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| 	\insn	%r3,0(%r2)
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| .L__memset_exit\bits:
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| 	BR_EX	%r14
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| .L__memset_mvc\bits:
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| 	mvc	\bytes(1,%r1),0(%r1)
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| .endm
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| 
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| __MEMSET 16,2,sth
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| EXPORT_SYMBOL(__memset16)
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| 
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| __MEMSET 32,4,st
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| EXPORT_SYMBOL(__memset32)
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| 
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| __MEMSET 64,8,stg
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| EXPORT_SYMBOL(__memset64)
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