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											2005-04-16 15:20:36 -07:00
										 |  |  | /* $Id: memset.S,v 1.1 2000/04/14 16:49:01 mjd Exp $ | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  * "memset" implementation of SuperH | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  * Copyright (C) 1999  Niibe Yutaka | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | /* | 
					
						
							|  |  |  |  *            void *memset(void *s, int c, size_t n);
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							|  |  |  |  */ | 
					
						
							|  |  |  | 
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							|  |  |  | #include <linux/linkage.h> | 
					
						
							|  |  |  | 
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							|  |  |  | ENTRY(memset) | 
					
						
							|  |  |  | 	tst	r6,r6 | 
					
						
							|  |  |  | 	bt/s	5f		! if n=0, do nothing | 
					
						
							|  |  |  | 	 add	r6,r4 | 
					
						
							|  |  |  | 	mov	#12,r0 | 
					
						
							|  |  |  | 	cmp/gt	r6,r0 | 
					
						
							|  |  |  | 	bt/s	4f		! if it's too small, set a byte at once | 
					
						
							|  |  |  | 	 mov	r4,r0 | 
					
						
							|  |  |  | 	and	#3,r0 | 
					
						
							|  |  |  | 	cmp/eq	#0,r0 | 
					
						
							|  |  |  | 	bt/s	2f		! It's aligned | 
					
						
							|  |  |  | 	 sub	r0,r6 | 
					
						
							|  |  |  | 1: | 
					
						
							|  |  |  | 	dt	r0 | 
					
						
							|  |  |  | 	bf/s	1b | 
					
						
							|  |  |  | 	 mov.b	r5,@-r4
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							|  |  |  | 2:				! make VVVV | 
					
						
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										 |  |  | 	extu.b	r5,r5 | 
					
						
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											2005-04-16 15:20:36 -07:00
										 |  |  | 	swap.b	r5,r0		!   V0 | 
					
						
							|  |  |  | 	or	r0,r5		!   VV | 
					
						
							|  |  |  | 	swap.w	r5,r0		! VV00 | 
					
						
							|  |  |  | 	or	r0,r5		! VVVV | 
					
						
							|  |  |  | 	! | 
					
						
							|  |  |  | 	mov	r6,r0 | 
					
						
							|  |  |  | 	shlr2	r0 | 
					
						
							|  |  |  | 	shlr	r0		! r0 = r6 >> 3 | 
					
						
							|  |  |  | 3: | 
					
						
							|  |  |  | 	dt	r0 | 
					
						
							|  |  |  | 	mov.l	r5,@-r4		! set 8-byte at once
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							|  |  |  | 	bf/s	3b | 
					
						
							|  |  |  | 	 mov.l	r5,@-r4
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							|  |  |  | 	! | 
					
						
							|  |  |  | 	mov	#7,r0 | 
					
						
							|  |  |  | 	and	r0,r6 | 
					
						
							|  |  |  | 	tst	r6,r6 | 
					
						
							|  |  |  | 	bt	5f | 
					
						
							|  |  |  | 	! fill bytes | 
					
						
							|  |  |  | 4: | 
					
						
							|  |  |  | 	dt	r6 | 
					
						
							|  |  |  | 	bf/s	4b | 
					
						
							|  |  |  | 	 mov.b	r5,@-r4
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							|  |  |  | 5: | 
					
						
							|  |  |  | 	rts | 
					
						
							|  |  |  | 	 mov	r4,r0 |