| The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame^] | 1 | /* $OpenBSD: strcmp.S,v 1.3 2005/08/07 11:30:38 espie Exp $ */ |
| 2 | /* |
| 3 | * Written by J.T. Conklin <jtc@netbsd.org>. |
| 4 | * Public domain. |
| 5 | */ |
| 6 | |
| 7 | #include <machine/asm.h> |
| 8 | |
| 9 | /* |
| 10 | * NOTE: I've unrolled the loop eight times: large enough to make a |
| 11 | * significant difference, and small enough not to totally trash the |
| 12 | * cache. |
| 13 | */ |
| 14 | |
| 15 | ENTRY(strcmp) |
| 16 | movl 0x04(%esp),%eax |
| 17 | movl 0x08(%esp),%edx |
| 18 | jmp L2 /* Jump into the loop! */ |
| 19 | |
| 20 | .align 2,0x90 |
| 21 | L1: incl %eax |
| 22 | incl %edx |
| 23 | L2: movb (%eax),%cl |
| 24 | testb %cl,%cl /* null terminator??? */ |
| 25 | jz L3 |
| 26 | cmpb %cl,(%edx) /* chars match??? */ |
| 27 | jne L3 |
| 28 | incl %eax |
| 29 | incl %edx |
| 30 | movb (%eax),%cl |
| 31 | testb %cl,%cl |
| 32 | jz L3 |
| 33 | cmpb %cl,(%edx) |
| 34 | jne L3 |
| 35 | incl %eax |
| 36 | incl %edx |
| 37 | movb (%eax),%cl |
| 38 | testb %cl,%cl |
| 39 | jz L3 |
| 40 | cmpb %cl,(%edx) |
| 41 | jne L3 |
| 42 | incl %eax |
| 43 | incl %edx |
| 44 | movb (%eax),%cl |
| 45 | testb %cl,%cl |
| 46 | jz L3 |
| 47 | cmpb %cl,(%edx) |
| 48 | jne L3 |
| 49 | incl %eax |
| 50 | incl %edx |
| 51 | movb (%eax),%cl |
| 52 | testb %cl,%cl |
| 53 | jz L3 |
| 54 | cmpb %cl,(%edx) |
| 55 | jne L3 |
| 56 | incl %eax |
| 57 | incl %edx |
| 58 | movb (%eax),%cl |
| 59 | testb %cl,%cl |
| 60 | jz L3 |
| 61 | cmpb %cl,(%edx) |
| 62 | jne L3 |
| 63 | incl %eax |
| 64 | incl %edx |
| 65 | movb (%eax),%cl |
| 66 | testb %cl,%cl |
| 67 | jz L3 |
| 68 | cmpb %cl,(%edx) |
| 69 | jne L3 |
| 70 | incl %eax |
| 71 | incl %edx |
| 72 | movb (%eax),%cl |
| 73 | testb %cl,%cl |
| 74 | jz L3 |
| 75 | cmpb %cl,(%edx) |
| 76 | je L1 |
| 77 | .align 2, 0x90 |
| 78 | L3: movzbl (%eax),%eax /* unsigned comparison */ |
| 79 | movzbl (%edx),%edx |
| 80 | subl %edx,%eax |
| 81 | ret |