From f95a4a932476be2ba99e2fd081e8d2bc6ea12813 Mon Sep 17 00:00:00 2001 From: PikalaxALT Date: Fri, 15 Dec 2017 09:38:53 -0500 Subject: Import newlib and create makefile --- newlib/libc/machine/i386/memmove.S | 74 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 newlib/libc/machine/i386/memmove.S (limited to 'newlib/libc/machine/i386/memmove.S') diff --git a/newlib/libc/machine/i386/memmove.S b/newlib/libc/machine/i386/memmove.S new file mode 100644 index 0000000..e1aca0d --- /dev/null +++ b/newlib/libc/machine/i386/memmove.S @@ -0,0 +1,74 @@ +/* + * ==================================================== + * Copyright (C) 1998 by Cygnus Solutions. All rights reserved. + * + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + + #include "i386mach.h" + + .global SYM (memmove) + +SYM (memmove): + + pushl ebp + movl esp,ebp + pushl esi + pushl edi + pushl ebx + movl 8(ebp),edi + movl 16(ebp),ecx + movl 12(ebp),esi + +/* check for destructive overlap (src < dst && dst < src + length) */ + + cld + cmpl edi,esi + jae .L2 + leal -1(ecx,esi),ebx + cmpl ebx,edi + ja .L2 + +/* destructive overlap, must copy backwards...do it a byte at a time since it is uncommon */ + + decl edi + movl ebx,esi + addl ecx,edi + std + jmp BYTEMOVE +.L2: +#ifndef __OPTIMIZE_SIZE__ +/* non-destructive overlap so we can try and move 4 bytes at a time */ + + movl esi,eax + orl edi,eax + testb $3,al + jne BYTEMOVE + shrl $2,ecx + rep + movsl + +/* calculate any remainder bytes after moving doublewords */ + + movl 16(ebp),ecx + andl $3,ecx + +#endif /* not __OPTIMIZE_SIZE__ */ + +/* move any unaligned bytes or remainder bytes, one at a time */ + +BYTEMOVE: + rep + movsb + + movl 8(ebp),eax + + leal -12(ebp),esp + popl ebx + popl edi + popl esi + leave + ret -- cgit v1.2.3