/*- * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Ralph Campbell. * * %sccs.include.redist.c% */ #include #if defined(LIBC_SCCS) && !defined(lint) ASMSTR("@(#)bzero.s 5.3 (Berkeley) 07/26/92") #endif /* LIBC_SCCS and not lint */ /* bzero(s1, n) */ LEAF(bzero) .set noreorder blt a1, 12, smallclr # small amount to clear? subu a3, zero, a0 # compute # bytes to word align address and a3, a3, 3 beq a3, zero, 1f # skip if word aligned subu a1, a1, a3 # subtract from remaining count swr zero, 0(a0) # clear 1, 2, or 3 bytes to align addu a0, a0, a3 1: and v0, a1, 3 # compute number of words left subu a3, a1, v0 move a1, v0 addu a3, a3, a0 # compute ending address 2: addu a0, a0, 4 # clear words bne a0, a3, 2b # unrolling loop doesn't help sw zero, -4(a0) # since we're limited by memory speed smallclr: ble a1, zero, 2f addu a3, a1, a0 # compute ending address 1: addu a0, a0, 1 # clear bytes bne a0, a3, 1b sb zero, -1(a0) 2: j ra nop END(bzero)