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--- Libc/Libc-320/ppc/string/strlen.s
+++ /dev/null
@@ -1,117 +0,0 @@
-/*
- * Copyright (c) 2000-2001 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-#define ASSEMBLER
-#include <mach/ppc/asm.h>
-#undef ASSEMBLER
-
-;
-;
-; Strlen, optimized for PPC. The routine we use is 2-3x faster
-; then the simple loop which checks each byte for zero.
-; For 0- and 1-byte strings, the simple routine is faster, but
-; only by a few cycles. The algorithm used was adapted from the
-; Mac OS 9 stdCLib strcopy routine, which was originally
-; written by Gary Davidian. It relies on the following rather
-; inobvious but very efficient test:
-;
-; y = dataWord + 0xFEFEFEFF
-; z = ~dataWord & 0x80808080
-; if ( y & z ) = 0 then all bytes in dataWord are non-zero
-;
-; The test maps any non-zero byte to zeros and any zero byte to 0x80,
-; with one exception: 0x01 bytes preceeding the first zero are also
-; mapped to 0x80.
-;
-;
-; int strlen(ptr)
-;
-;
-
- .align 5
- .globl EXT(strlen)
-LEXT(strlen)
-
- andi. r4,r3,0x03 ; test alignment first
- mr r9,r3 ; store the original address for later use....
- bne LalignSource ; align the source addr if not already aligned
-Llentry:
- lis r5,hi16(0xFEFEFEFF)
- lis r6,hi16(0x80808080)
- subi r3,r3,0x04 ; pre-decrement r3 for the lwzu
- ori r5,r5,lo16(0xFEFEFEFF) ; r5=0xFEFEFEFF
- ori r6,r6,lo16(0x80808080) ; r6=0x80808080
-
-LLoop:
- lwzu r8,4(r3) ; get the first 4 bytes and increment address
- add r4,r5,r8 ; r4= data + 0xFEFEFEFF
- andc r7,r6,r8 ; r7= ~data & 0x80808080
- and. r4,r4,r7 ; r4= r4 & r7
- beq LLoop ; if r4 is zero, then all bytes are non-zero
-
-; Now we know one of the bytes in r8 is zero,
-; we just have to figure out which one.
-; We have mapped 0 bytes to 0x80, and nonzero bytes to 0x00,
-; with one exception:
-; 0x01 bytes preceeding the first zero are also mapped to 0x80.
-; So we have to mask out the 0x80s caused by 0x01s before
-; counting leading zeroes to get the bytes in last word.
-
- rlwinm r5,r8,7,0,31 ; move 0x01 bits to 0x80 position
- subf r3,r9,r3 ; start to compute string length
- andc r4,r4,r5 ; turn off false hits from 0x0100 worst case
- cntlzw r7,r4 ; now we can count leading 0s
- srwi r7,r7,3 ; convert 0,8,16,24 to 0,1,2,3
- add r3,r3,r7 ; add in nonzero bytes in last word
- blr
-
-; We must align the source address for two reasons: to avoid spurious page
-; faults, and for speed.
-; r4 = low 2 bits of address (1,2, or 3)
-; r3 = address
-; r9 = original address (still same as r3)
-
-LalignSource:
- lbz r5,0(r3) ; get the first byte...
- subic. r4,r4,2 ; test for 1, 2 or 3 bytes
- addi r3,r3,1 ; increment address
- addi r6,r9,1 ; now r6==r3
- cmpwi cr1,r5,0 ; zero?
- beq cr1,Lreturn ; if its zero return zero
- bgt Llentry ; address is aligned now if low bits were 3
-
- lbz r5,0(r3) ; get the next byte...
- addi r3,r3,1 ; increment address
- cmpwi cr1,r5,0 ; zero?
- beq cr1,Lreturn ; if its zero return one
- beq Llentry ; addr is aligned now if low bits were 2
-
- lbz r5,0(r3) ; get the next byte...
- addi r3,r3,1 ; increment address
- cmpwi cr1,r5,0 ; zero?
- bne cr1,Llentry ; not zero, continue check (now aligned)
-Lreturn:
- sub r3,r3,r6 ; get string length (0, 1, or 2)
- blr
-