diff options
Diffstat (limited to 'newlib/libc/machine/i386/strlen.S')
| -rw-r--r-- | newlib/libc/machine/i386/strlen.S | 65 |
1 files changed, 1 insertions, 64 deletions
diff --git a/newlib/libc/machine/i386/strlen.S b/newlib/libc/machine/i386/strlen.S index 0e3cb640c..459b3a959 100644 --- a/newlib/libc/machine/i386/strlen.S +++ b/newlib/libc/machine/i386/strlen.S @@ -1,6 +1,6 @@ /* * ==================================================== - * Copyright (C) 1998, 2002, 2008 by Red Hat Inc. All rights reserved. + * Copyright (C) 1998, 2002 by Red Hat Inc. All rights reserved. * * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice @@ -20,75 +20,12 @@ SYM (strlen): pushl edi movl 8(ebp),edx -#ifdef __OPTIMIZE_SIZE__ cld movl edx,edi movl $4294967295,ecx xor eax,eax repnz scasb -#else -/* Modern x86 hardware is much faster at double-word - manipulation than with bytewise repnz scasb. */ - -/* Do byte-wise checks until string is aligned. */ - movl edx,edi - test $3,edi - je L5 - movb (edi),cl - incl edi - testb cl,cl - je L15 - - test $3,edi - je L5 - movb (edi),cl - incl edi - testb cl,cl - je L15 - - test $3,edi - je L5 - movb (edi),cl - incl edi - testb cl,cl - je L15 - -L5: - subl $4,edi - -/* loop performing 4 byte mask checking for desired 0 byte */ - .p2align 4,,7 -L10: - addl $4,edi - movl (edi),ecx - leal -16843009(ecx),eax - notl ecx - andl ecx,eax - testl $-2139062144,eax - je L10 - -/* Find which of four bytes is 0. */ - notl ecx - incl edi - - testb cl,cl - je L15 - incl edi - shrl $8,ecx - - testb cl,cl - je L15 - incl edi - shrl $8,ecx - - testb cl,cl - je L15 - incl edi - -#endif - -L15: subl edx,edi leal -1(edi),eax |