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- TEXT strcpy(SB), $0
- MOVW s2+4(FP),R2 /* R2 is from pointer */
- MOVW R1, R3 /* R3 is to pointer */
- /*
- * align 'from' pointer
- */
- l1:
- AND $3, R2, R5
- ADDU $1, R2
- BEQ R5, l2
- MOVB -1(R2), R5
- ADDU $1, R3
- MOVB R5, -1(R3)
- BNE R5, l1
- RET
- /*
- * test if 'to' is also alligned
- */
- l2:
- AND $3,R3, R5
- BEQ R5, l4
- /*
- * copy 4 at a time, 'to' not aligned
- */
- l3:
- MOVW -1(R2), R4
- ADD $4, R2
- ADD $4, R3
- SRL $24,R4, R5
- MOVB R5, -4(R3)
- BEQ R5, out
- SRL $16,R4, R5
- AND $0xff, R5
- MOVB R5, -3(R3)
- BEQ R5, out
- SRL $8,R4, R5
- AND $0xff, R5
- MOVB R5, -2(R3)
- BEQ R5, out
- AND $0xff,R4, R5
- MOVB R5, -1(R3)
- BNE R5, l3
- out:
- RET
- /*
- * word at a time both aligned
- */
- l4:
- MOVW $0xff000000, R7
- MOVW $0x00ff0000, R8
- l5:
- ADDU $4, R3
- MOVW -1(R2), R4 /* fetch */
- ADDU $4, R2
- AND R7,R4, R5 /* is it byte 0 */
- AND R8,R4, R6 /* is it byte 1 */
- BEQ R5, b0
- AND $0xff00,R4, R5 /* is it byte 2 */
- BEQ R6, b1
- AND $0xff,R4, R6 /* is it byte 3 */
- BEQ R5, b2
- MOVW R4, -4(R3) /* store */
- BNE R6, l5
- JMP out
- b0:
- MOVB $0, -4(R3)
- JMP out
- b1:
- SRL $24, R4
- MOVB R4, -4(R3)
- MOVB $0, -3(R3)
- JMP out
- b2:
- SRL $24,R4, R5
- MOVB R5, -4(R3)
- SRL $16, R4
- MOVB R4, -3(R3)
- MOVB $0, -2(R3)
- JMP out
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