diff options
author | Christopher Faylor <me@cgf.cx> | 2000-02-17 22:39:52 +0300 |
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committer | Christopher Faylor <me@cgf.cx> | 2000-02-17 22:39:52 +0300 |
commit | 8a0efa53e44919bcf5ccb1d3353618a82afdf8bc (patch) | |
tree | 68c3dbf3f2c6fd5d49777def9914d77b5cd4589d /newlib/libc/machine/i386/strchr.S | |
parent | 1fd5e000ace55b323124c7e556a7a864b972a5c4 (diff) |
import newlib-2000-02-17 snapshot
Diffstat (limited to 'newlib/libc/machine/i386/strchr.S')
-rw-r--r-- | newlib/libc/machine/i386/strchr.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/newlib/libc/machine/i386/strchr.S b/newlib/libc/machine/i386/strchr.S new file mode 100644 index 000000000..f224f380c --- /dev/null +++ b/newlib/libc/machine/i386/strchr.S @@ -0,0 +1,84 @@ +/* + * ==================================================== + * 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 (strchr) + +SYM (strchr): + + pushl ebp + movl esp,ebp + pushl edi + pushl ebx + xorl ebx,ebx + movl 8(ebp),edi + movb 12(ebp),bl + +#ifndef __OPTIMIZE_SIZE__ +/* check if string is aligned, if not do check one byte at a time */ + test $3,edi + jne L9 + +/* create 4 byte mask which is just the desired byte repeated 4 times */ + movl ebx,ecx + sall $8,ebx + subl $4,edi + orl ecx,ebx + movl ebx,edx + sall $16,ebx + orl edx,ebx + +/* loop performing 4 byte mask checking for 0 byte or desired byte */ + .p2align 4,,7 +L10: + addl $4,edi + movl (edi),ecx + leal -16843009(ecx),edx + movl ecx,eax + notl eax + andl eax,edx + testl $-2139062144,edx + jne L9 + + movl ebx,eax + xorl ecx,eax + leal -16843009(eax),edx + notl eax + andl eax,edx + testl $-2139062144,edx + je L10 +#endif /* not __OPTIMIZE_SIZE__ */ + +/* loop while (*s && *s++ != c) */ +L9: + leal -1(edi),eax + .p2align 4,,7 +L15: + incl eax + movb (eax),dl + testb dl,dl + je L14 + cmpb bl,dl + jne L15 + +L14: +/* if (*s == c) return address otherwise return NULL */ + cmpb bl,(eax) + je L19 + xorl eax,eax + +L19: + leal -8(ebp),esp + popl ebx + popl edi + leave + ret + |