/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ * */ #include <ppc/asm.h> #include <ppc/proc_reg.h> # # void setbit(int bitno, int *s) # # Set indicated bit in bit string. # Note: being big-endian, bit 0 is 0x80000000. ENTRY(setbit,TAG_NO_FRAME_USED) rlwinm r8,r3,29,3,31 /* Get byte displacement */ rlwinm r9,r3,0,29,31 /* Get bit within byte */ li r6,0x80 /* Start with bit 0 */ lbzx r5,r4,r8 /* Grab target byte */ srw r6,r6,r9 /* Get the right bit (fits right into the load cycle) */ or r5,r5,r6 /* Turn on the right bit */ stbx r5,r4,r8 /* Save the byte back */ blr # # void clrbit(int bitno, int *s) # # Clear indicated bit in bit string. # Note: being big-endian, bit 0 is 0x80000000. ENTRY(clrbit,TAG_NO_FRAME_USED) rlwinm r8,r3,29,3,31 /* Get byte displacement */ rlwinm r9,r3,0,29,31 /* Get bit within byte */ li r6,0x80 /* Start with bit 0 */ lbzx r5,r4,r8 /* Grab target byte */ srw r6,r6,r9 /* Get the right bit (fits right into the load cycle) */ andc r5,r5,r6 /* Turn off the right bit */ stbx r5,r4,r8 /* Save the byte back */ blr # /* # * Find first bit set in bit string. # */ # int # ffsbit(int *s) # # Returns the bit index of the first bit set (starting from 0) # Assumes pointer is word-aligned ENTRY(ffsbit, TAG_NO_FRAME_USED) lwz r0, 0(ARG0) mr ARG1, ARG0 /* Free up ARG0 for result */ cmpwi r0, 0 /* Check against zero... */ cntlzw ARG0, r0 /* Free inst... find the set bit... */ bnelr+ /* Return if bit in first word */ .L_ffsbit_lp: lwz r0, 4(ARG1) addi ARG1, ARG1, 4 cmpwi r0, 0 /* Check against zero... */ cntlzw r12, r0 add ARG0, ARG0, r12 /* ARG0 keeps bit count */ beq+ .L_ffsbit_lp blr /* * int tstbit(int bitno, int *s) * * Test indicated bit in bit string. * Note: being big-endian, bit 0 is 0x80000000. */ ENTRY2(tstbit, testbit, TAG_NO_FRAME_USED) rlwinm r8,r3,29,3,31 /* Get byte displacement */ rlwinm r9,r3,0,29,31 /* Get bit within byte */ lbzx r5,r4,r8 /* Grab target byte */ addi r9,r9,25 /* Get actual shift value */ rlwnm r3,r5,r9,31,31 /* Pass the bit back */ blr