/* * Written by J.T. Conklin . * Public domain. * Adapted for NetBSD/x86_64 by Frank van der Linden */ #include #if defined(LIBC_SCCS) RCSID("$NetBSD: strcmp.S,v 1.1 2001/06/19 00:22:47 fvdl Exp $") #endif /* * NOTE: I've unrolled the loop eight times: large enough to make a * significant difference, and small enough not to totally trash the * cache. */ ENTRY(strcmp) jmp L2 /* Jump into the loop. */ L1: incq %rdi incq %rsi L2: movb (%rdi),%cl testb %cl,%cl /* null terminator */ jz L3 cmpb %cl,(%rsi) /* chars match */ jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) jne L3 incq %rdi incq %rsi movb (%rdi),%cl testb %cl,%cl jz L3 cmpb %cl,(%rsi) je L1 L3: movzbl (%rdi),%eax /* unsigned comparison */ movzbl (%rsi),%edx subl %edx,%eax ret