83 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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| (C) Copyright IBM Corp. 2005, 2006
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| 
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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 name of IBM nor the names of its contributors may be 
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| used to endorse or promote products derived from this software without 
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| specific prior written permission.
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| 
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| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
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| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
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| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
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| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
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| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
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| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
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| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
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| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
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| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
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| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
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| POSSIBILITY OF SUCH DAMAGE.
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| 
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| Author: Andreas Neukoetter (ti95neuk@de.ibm.com)
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| */
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| 
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| #include <sys/types.h>
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| #include <errno.h>
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| #include <spu_intrinsics.h>
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| 
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| extern caddr_t  _end;
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| #define STACKSIZE 4096
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| 
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| void *
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| sbrk (ptrdiff_t increment)
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| {
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| 	static caddr_t heap_ptr = NULL;
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| 	caddr_t base;
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| 	vector unsigned int sp_reg, sp_delta;
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| 	vector unsigned int *sp_ptr;
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| 	caddr_t sps;
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| 
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| 	/* The stack pointer register.  */
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| 	volatile register vector unsigned int sp_r1 __asm__("1");
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| 	
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| 	if (heap_ptr == NULL)
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| 	  heap_ptr = (caddr_t) & _end;
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| 	
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| 	sps = (caddr_t) spu_extract (sp_r1, 0);
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| 	if (((int) sps - STACKSIZE - (int) heap_ptr) >= increment)
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| 	  {
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| 	    base = heap_ptr;
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| 	    heap_ptr += increment;
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| 	    
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| 	    sp_delta = (vector unsigned int) spu_insert (increment, spu_splats (0), 1);
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| 
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| 	    /* Subtract sp_delta from the SP limit (word 1).  */
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| 	    sp_r1 = spu_sub (sp_r1, sp_delta);
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| 	    
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| 	    /* Fix-up backchain.  */
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| 	    sp_ptr = (vector unsigned int *) spu_extract (sp_r1, 0);
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| 	    do
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| 	      {
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| 		sp_reg = *sp_ptr;
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| 		*sp_ptr = (vector unsigned int) spu_sub (sp_reg, sp_delta);
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| 	      }
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| 	    while ((sp_ptr = (vector unsigned int *) spu_extract (sp_reg, 0)));
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| 
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| 	    return (base);
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| 	  }
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| 	else
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| 	  {
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| 	    errno = ENOMEM;
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| 	    return ((void *) -1);
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| 	  }
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| }
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