108 lines
		
	
	
	
		
			1.6 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			108 lines
		
	
	
	
		
			1.6 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|   | /* | ||
|  |  * "memset" implementation for SH4 | ||
|  |  * | ||
|  |  * Copyright (C) 1999  Niibe Yutaka | ||
|  |  * Copyright (c) 2009  STMicroelectronics Limited | ||
|  |  * Author: Stuart Menefy <stuart.menefy:st.com> | ||
|  |  */ | ||
|  | 
 | ||
|  | /* | ||
|  |  *            void *memset(void *s, int c, size_t n);
 | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <linux/linkage.h> | ||
|  | 
 | ||
|  | ENTRY(memset) | ||
|  | 	mov	#12,r0 | ||
|  | 	add	r6,r4 | ||
|  | 	cmp/gt	r6,r0 | ||
|  | 	bt/s	40f		! 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
 | ||
|  | 2:				! make VVVV | ||
|  | 	extu.b	r5,r5 | ||
|  | 	swap.b	r5,r0		!   V0 | ||
|  | 	or	r0,r5		!   VV | ||
|  | 	swap.w	r5,r0		! VV00 | ||
|  | 	or	r0,r5		! VVVV | ||
|  | 
 | ||
|  | 	! Check if enough bytes need to be copied to be worth the big loop | ||
|  | 	mov	#0x40, r0	! (MT) | ||
|  | 	cmp/gt	r6,r0		! (MT)  64 > len => slow loop | ||
|  | 
 | ||
|  | 	bt/s	22f | ||
|  | 	 mov	r6,r0 | ||
|  | 
 | ||
|  | 	! align the dst to the cache block size if necessary | ||
|  | 	mov	r4, r3 | ||
|  | 	mov	#~(0x1f), r1 | ||
|  | 
 | ||
|  | 	and	r3, r1 | ||
|  | 	cmp/eq	r3, r1 | ||
|  | 
 | ||
|  | 	bt/s	11f		! dst is already aligned | ||
|  | 	 sub	r1, r3		! r3-r1 -> r3 | ||
|  | 	shlr2	r3		! number of loops | ||
|  | 
 | ||
|  | 10:	mov.l	r5,@-r4
 | ||
|  | 	dt	r3 | ||
|  | 	bf/s	10b | ||
|  | 	 add	#-4, r6 | ||
|  | 
 | ||
|  | 11:	! dst is 32byte aligned | ||
|  | 	mov	r6,r2 | ||
|  | 	mov	#-5,r0 | ||
|  | 	shld	r0,r2		! number of loops | ||
|  | 
 | ||
|  | 	add	#-32, r4 | ||
|  | 	mov	r5, r0 | ||
|  | 12: | ||
|  | 	movca.l	r0,@r4
 | ||
|  | 	mov.l	r5,@(4, r4)
 | ||
|  | 	mov.l	r5,@(8, r4)
 | ||
|  | 	mov.l	r5,@(12,r4)
 | ||
|  | 	mov.l	r5,@(16,r4)
 | ||
|  | 	mov.l	r5,@(20,r4)
 | ||
|  | 	add	#-0x20, r6 | ||
|  | 	mov.l	r5,@(24,r4)
 | ||
|  | 	dt	r2 | ||
|  | 	mov.l	r5,@(28,r4)
 | ||
|  | 	bf/s	12b | ||
|  | 	 add	#-32, r4 | ||
|  | 
 | ||
|  | 	add	#32, r4 | ||
|  | 	mov	#8, r0 | ||
|  | 	cmp/ge	r0, r6 | ||
|  | 	bf	40f | ||
|  | 
 | ||
|  | 	mov	r6,r0 | ||
|  | 22: | ||
|  | 	shlr2	r0 | ||
|  | 	shlr	r0		! r0 = r6 >> 3 | ||
|  | 3: | ||
|  | 	dt	r0 | ||
|  | 	mov.l	r5,@-r4		! set 8-byte at once
 | ||
|  | 	bf/s	3b | ||
|  | 	 mov.l	r5,@-r4
 | ||
|  | 	! | ||
|  | 	mov	#7,r0 | ||
|  | 	and	r0,r6 | ||
|  | 
 | ||
|  | 	! fill bytes (length may be zero) | ||
|  | 40:	tst	r6,r6 | ||
|  | 	bt	5f | ||
|  | 4: | ||
|  | 	dt	r6 | ||
|  | 	bf/s	4b | ||
|  | 	 mov.b	r5,@-r4
 | ||
|  | 5: | ||
|  | 	rts | ||
|  | 	 mov	r4,r0 |