/* $NetBSD: memset.S,v 1.2 1999/03/15 06:34:10 jonathan Exp $ */ #include #include #include .set noreorder /* * memset(void *s1, int c, int len) */ LEAF(memset) .set noreorder blt a2, 12, smallclr # small amount to clear? move v0, a0 # save s1 for result sll t1, a1, 8 # compute c << 8 in t1 or t1, t1, a1 # compute c << 8 | c in 11 sll t2, t1, 16 # shift that left 16 or t1, t2, t1 # or together subu t0, zero, a0 # compute # bytes to word align address and t0, t0, 3 beq t0, zero, 1f # skip if word aligned subu a2, a2, t0 # subtract from remaining count SWHI t1, 0(a0) # store 1, 2, or 3 bytes to align addu a0, a0, t0 1: and v1, a2, 3 # compute number of whole words left subu t0, a2, v1 subu a2, a2, t0 addu t0, t0, a0 # compute ending address 2: addu a0, a0, 4 # clear words bne a0, t0, 2b # unrolling loop does not help sw t1, -4(a0) # since we are limited by memory speed smallclr: ble a2, zero, 2f addu t0, a2, a0 # compute ending address 1: addu a0, a0, 1 # clear bytes bne a0, t0, 1b sb a1, -1(a0) 2: j ra nop .set reorder END(memset)