strcpy.S (1076B)
1 /* $Id: //depot/blt/lib/strcpy.S#1 $ */ 2 3 /* $OpenBSD: strcpy.S,v 1.2 1996/09/27 06:47:50 mickey Exp $ */ 4 5 /* 6 * Written by J.T. Conklin <jtc@netbsd.org>. 7 * Public domain. 8 */ 9 10 /* 11 * NOTE: I've unrolled the loop eight times: large enough to make a 12 * significant difference, and small enough not to totally trash the 13 * cache. 14 */ 15 16 #include <i386/asm.h> 17 18 FUNCTION (strcpy) 19 movl 4(%esp),%ecx /* dst address */ 20 movl 8(%esp),%edx /* src address */ 21 pushl %ecx /* push dst address */ 22 23 .align 2,0x90 24 L1: movb (%edx),%al /* unroll loop, but not too much */ 25 movb %al,(%ecx) 26 testb %al,%al 27 jz L2 28 movb 1(%edx),%al 29 movb %al,1(%ecx) 30 testb %al,%al 31 jz L2 32 movb 2(%edx),%al 33 movb %al,2(%ecx) 34 testb %al,%al 35 jz L2 36 movb 3(%edx),%al 37 movb %al,3(%ecx) 38 testb %al,%al 39 jz L2 40 movb 4(%edx),%al 41 movb %al,4(%ecx) 42 testb %al,%al 43 jz L2 44 movb 5(%edx),%al 45 movb %al,5(%ecx) 46 testb %al,%al 47 jz L2 48 movb 6(%edx),%al 49 movb %al,6(%ecx) 50 testb %al,%al 51 jz L2 52 movb 7(%edx),%al 53 movb %al,7(%ecx) 54 addl $8,%edx 55 addl $8,%ecx 56 testb %al,%al 57 jnz L1 58 L2: popl %eax /* pop dst address */ 59 ret