62 lines
		
	
	
	
		
			747 B
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			62 lines
		
	
	
	
		
			747 B
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|   | /* memset.S */ | ||
|  | 
 | ||
|  | #include <asm/linkage.h> | ||
|  | 
 | ||
|  | #if defined(__H8300H__)  | ||
|  | 	.h8300h | ||
|  | #endif | ||
|  | #if defined(__H8300S__)  | ||
|  | 	.h8300s | ||
|  | #endif | ||
|  | 	.text | ||
|  | 
 | ||
|  | .global	SYMBOL_NAME(memset) | ||
|  | 
 | ||
|  | ;;void *memset(*ptr, int c, size_t count)
 | ||
|  | ;; ptr = er0
 | ||
|  | ;; c   = er1(r1l)
 | ||
|  | ;; count = er2
 | ||
|  | SYMBOL_NAME_LABEL(memset) | ||
|  | 	btst	#0,r0l | ||
|  | 	beq	2f | ||
|  | 
 | ||
|  | 	;; odd address
 | ||
|  | 1: | ||
|  | 	mov.b	r1l,@er0
 | ||
|  | 	adds	#1,er0 | ||
|  | 	dec.l	#1,er2 | ||
|  | 	beq	6f | ||
|  | 
 | ||
|  | 	;; even address
 | ||
|  | 2: | ||
|  | 	mov.l	er2,er3 | ||
|  | 	cmp.l	#4,er2 | ||
|  | 	blo	4f | ||
|  | 	;; count>=4 -> count/4
 | ||
|  | #if defined(__H8300H__) | ||
|  | 	shlr.l	er2 | ||
|  | 	shlr.l	er2 | ||
|  | #endif | ||
|  | #if defined(__H8300S__) | ||
|  | 	shlr.l	#2,er2 | ||
|  | #endif | ||
|  | 	;; byte -> long
 | ||
|  | 	mov.b	r1l,r1h | ||
|  | 	mov.w	r1,e1 | ||
|  | 3: | ||
|  | 	mov.l	er1,@er0
 | ||
|  | 	adds	#4,er0 | ||
|  | 	dec.l	#1,er2 | ||
|  | 	bne	3b | ||
|  | 4: | ||
|  | 	;; count % 4
 | ||
|  | 	and.b	#3,r3l | ||
|  | 	beq	6f | ||
|  | 5: | ||
|  | 	mov.b	r1l,@er0
 | ||
|  | 	adds	#1,er0 | ||
|  | 	dec.b	r3l | ||
|  | 	bne	5b | ||
|  | 6: | ||
|  | 	rts |