76 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			76 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|   (C) Copyright 2008
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|   International Business Machines Corporation,
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|   All rights reserved.
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| 
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|   Redistribution and use in source and binary forms, with or without
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|   modification, are permitted provided that the following conditions are met:
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| 
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|     * Redistributions of source code must retain the above copyright notice,
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|   this list of conditions and the following disclaimer.
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|     * Redistributions in binary form must reproduce the above copyright
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|   notice, this list of conditions and the following disclaimer in the
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|   documentation and/or other materials provided with the distribution.
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|     * Neither the names of the copyright holders nor the names of their
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|   contributors may be used to endorse or promote products derived from
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|   this software without specific prior written permission.
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| 
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|   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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|   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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|   TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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|   PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
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|   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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|   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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|   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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|   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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|   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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|   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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|   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| */
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| 
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| #include <spu_intrinsics.h>
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| #include "vec_literal.h"
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| 
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| /*
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|  * Supply the inline _straddr for use by strncpy and strncat.
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| *
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| * _straddr: search the string s, and return the address of the first byte
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| * containing zero.
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| */
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| static inline char *_straddr(const char *s)
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| {
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|   unsigned int cnt, cmp, skip, mask;
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|   vec_uchar16 *ptr, data;
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| 
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|   /*
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|    * Compensate for unaligned strings.
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|    */
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|   ptr = (vec_uchar16 *)s; /* implicit (s & ~0xf) */
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|   skip = (unsigned int)(ptr) & 0xf;
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|   /*
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|    * skip the first skip bytes starting at (s & ~0xf).
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|    */
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|   mask = 0xFFFF >> skip;
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| 
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|   data = *ptr;
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|   cmp = spu_extract(spu_gather(spu_cmpeq(data, 0)), 0);
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|   cmp &= mask;
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| 
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|   cnt = spu_extract(spu_cntlz(spu_promote(cmp, 0)), 0);
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| 
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|   while (cnt == 32) {
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|     data = *++ptr;
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|     cnt = spu_extract(spu_cntlz(spu_gather(spu_cmpeq(data, 0))), 0);
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|     /*
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|      * The first 16 bits for gather on a byte vector are zero, so if cnt
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|      * is 32, none of the 16 bytes in data was zero. And, there are (cnt -
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|      * 16) non-zero bytes in data.
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|      */
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|   }
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|   /*
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|    * The first non-zero byte is at ptr aligned down plus the number of
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|    * non-zero bytes seen.
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|    */
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|   return ((char*) (((int) ptr & ~0xf) + (cnt - 16)));
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| }
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