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49 lines
688 B
ArmAsm
49 lines
688 B
ArmAsm
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/*
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* void *memcpy (void *to, const void *from, size_t count)
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*
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* Some optimization research can be found in media/doc/memcpy_optimize.txt
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*/
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.globl _memcpy
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_memcpy:
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push %ebp
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mov %esp,%ebp
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push %esi
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push %edi
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mov 0x8(%ebp),%edi
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mov 0xc(%ebp),%esi
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mov 0x10(%ebp),%ecx
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cld
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cmp $16,%ecx
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jb .L1
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mov %ecx,%edx
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test $3,%edi
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je .L2
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/*
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* Make the destination dword aligned
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*/
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mov %edi,%ecx
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and $3,%ecx
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sub $5,%ecx
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not %ecx
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sub %ecx,%edx
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rep movsb
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mov %edx,%ecx
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.L2:
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shr $2,%ecx
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rep movsl
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mov %edx,%ecx
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and $3,%ecx
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.L1:
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test %ecx,%ecx
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je .L3
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rep movsb
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.L3:
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pop %edi
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pop %esi
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mov 0x8(%ebp),%eax
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leave
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ret
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