forked from Bananymous/banan-os
88 lines
1.4 KiB
ArmAsm
88 lines
1.4 KiB
ArmAsm
.global memchr
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memchr:
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xchgl 4(%esp), %edi
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movl 8(%esp), %eax
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movl 12(%esp), %ecx
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movl $1, %edx
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cmpl $1, %ecx # clear ZF if count is zero
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repne scasb
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cmovel %edi, %edx
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leal -1(%edx), %eax
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movl 4(%esp), %edi
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ret
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.global memcmp
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memcmp:
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xchgl 4(%esp), %edi
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xchgl 8(%esp), %esi
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movl 12(%esp), %ecx
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testl %ecx, %ecx # set ZF if count is zero
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repe cmpsb
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jne .memcmp_not_equal
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xorl %eax, %eax
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jmp .memcmp_done
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.memcmp_not_equal:
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movzbl -1(%edi), %eax
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movzbl -1(%esi), %ecx
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subl %ecx, %eax
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.memcmp_done:
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movl 4(%esp), %edi
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movl 8(%esp), %esi
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ret
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.global memcpy
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memcpy:
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xchgl 4(%esp), %edi
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xchgl 8(%esp), %esi
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movl 12(%esp), %ecx
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movl %edi, %edx
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rep movsb
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movl 4(%esp), %edi
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movl 8(%esp), %esi
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movl %edx, %eax
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ret
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.global memmove
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memmove:
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xchgl 4(%esp), %edi
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xchgl 8(%esp), %esi
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movl 12(%esp), %ecx
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movl %edi, %edx
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cmpl %edi, %esi
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jb .memmove_slow
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rep movsb
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.memmove_done:
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movl 4(%esp), %edi
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movl 8(%esp), %esi
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movl %edx, %eax
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ret
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.memmove_slow:
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leal -1(%edi, %ecx), %edi
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leal -1(%esi, %ecx), %esi
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std
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rep movsb
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cld
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jmp .memmove_done
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.global memset
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memset:
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xchgl 4(%esp), %edi
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movl 8(%esp), %eax
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movl 12(%esp), %ecx
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movl %edi, %edx
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rep stosb
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movl 4(%esp), %edi
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movl %edx, %eax
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ret
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.global strlen
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strlen:
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xchgl 4(%esp), %edi
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xorb %al, %al
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movl $-1, %ecx
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repne scasb
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movl 4(%esp), %edi
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movl $-2, %eax
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subl %ecx, %eax
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ret
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