/* * R4000-compatible memset uses V instructions. * The kernel uses the 3000 compilers, but we can * use this procedure for speed. */ TEXT memset(SB),$16 MOVW R1, 0(FP) MOVW n+8(FP), R3 /* R3 is count */ MOVW p+0(FP), R4 /* R4 is pointer */ MOVW c+4(FP), R5 /* R5 is char */ ADDU R3,R4, R6 /* R6 is end pointer */ /* * if not at least 8 chars, * dont even mess around. * 7 chars to guarantee any * rounding up to a word * boundary and 8 characters * to get at least maybe one * full word store. */ SGT $8,R3, R1 BNE R1, out /* * turn R5 into a doubleword of characters */ AND $0xff, R5 SLLV $8,R5, R1 OR R1, R5 SLLV $16,R5, R1 OR R1, R5 SLLV $32,R5, R1 OR R1, R5 /* * store one byte at a time until pointer * is alligned on a doubleword boundary */ l1: AND $7,R4, R1 BEQ R1, l2 MOVB R5, 0(R4) ADDU $1, R4 JMP l1 /* * turn R3 into end pointer-31 * store 32 at a time while theres room */ l2: ADDU $-31,R6, R3 l3: SGTU R3,R4, R1 BEQ R1, l4 MOVV R5, 0(R4) MOVV R5, 8(R4) ADDU $32, R4 MOVV R5, -16(R4) MOVV R5, -8(R4) JMP l3 /* * turn R3 into end pointer-3 * store 4 at a time while theres room */ l4: ADDU $-3,R6, R3 l5: SGTU R3,R4, R1 BEQ R1, out MOVW R5, 0(R4) ADDU $4, R4 JMP l5 /* * last loop, store byte at a time */ out: SGTU R6,R4 ,R1 BEQ R1, ret MOVB R5, 0(R4) ADDU $1, R4 JMP out ret: MOVW s1+0(FP), R1 RET END