| bzero.S (178580) | bzero.S (209231) |
|---|---|
| 1/* $NetBSD: bzero.S,v 1.8 2003/08/07 16:42:16 agc Exp $ */ | 1/* $NetBSD: bzero.S,v 1.10 2009/12/14 02:53:52 matt Exp $ */ |
| 2 3/*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Ralph Campbell. 9 * --- 18 unchanged lines hidden (view full) --- 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <machine/asm.h> | 2 3/*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Ralph Campbell. 9 * --- 18 unchanged lines hidden (view full) --- 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <machine/asm.h> |
| 36__FBSDID("$FreeBSD: head/lib/libc/mips/string/bzero.S 178580 2008-04-26 12:08:02Z imp $"); | 36__FBSDID("$FreeBSD: head/lib/libc/mips/string/bzero.S 209231 2010-06-16 12:55:14Z jchandra $"); |
| 37 38#if defined(LIBC_SCCS) && !defined(lint) | 37 38#if defined(LIBC_SCCS) && !defined(lint) |
| 39#if 0 |
|
| 39 ASMSTR("from: @(#)bzero.s 8.1 (Berkeley) 6/4/93") | 40 ASMSTR("from: @(#)bzero.s 8.1 (Berkeley) 6/4/93") |
| 40 ASMSTR("$NetBSD: bzero.S,v 1.8 2003/08/07 16:42:16 agc Exp $") | 41#else 42 ASMSTR("$NetBSD: bzero.S,v 1.10 2009/12/14 02:53:52 matt Exp $") 43#endif |
| 41#endif /* LIBC_SCCS and not lint */ 42 | 44#endif /* LIBC_SCCS and not lint */ 45 |
| 46#define _LOCORE /* XXX not really, just assembly-code source */ 47#include <machine/endian.h> |
|
| 43 44#ifdef __ABICALLS__ 45 .abicalls 46#endif 47 48/* bzero(s1, n) */ 49 50LEAF(bzero) 51 .set noreorder | 48 49#ifdef __ABICALLS__ 50 .abicalls 51#endif 52 53/* bzero(s1, n) */ 54 55LEAF(bzero) 56 .set noreorder |
| 52 blt a1, 12, smallclr # small amount to clear? 53 subu a3, zero, a0 # compute # bytes to word align address 54 and a3, a3, 3 55 beq a3, zero, 1f # skip if word aligned 56 subu a1, a1, a3 # subtract from remaining count 57#ifdef __MIPSEB__ 58 swl zero, 0(a0) # clear 1, 2, or 3 bytes to align 59#else 60 swr zero, 0(a0) # clear 1, 2, or 3 bytes to align | 57 blt a1, 3*SZREG, smallclr # small amount to clear? 58 PTR_SUBU a3, zero, a0 # compute # bytes to word align address 59 and a3, a3, SZREG-1 60 beq a3, zero, 1f # skip if word aligned 61#if SZREG == 4 62 PTR_SUBU a1, a1, a3 # subtract from remaining count 63 SWHI zero, 0(a0) # clear 1, 2, or 3 bytes to align 64 PTR_ADDU a0, a0, a3 |
| 61#endif | 65#endif |
| 62 addu a0, a0, a3 | 66#if SZREG == 8 67 PTR_SUBU a1, a1, a3 # subtract from remaining count 68 PTR_ADDU a0, a0, a3 # align dst to next word 69 sll a3, a3, 3 # bits to bytes 70 li a2, -1 # make a mask 71#if _BYTE_ORDER == _BIG_ENDIAN 72 REG_SRLV a2, a2, a3 # we want to keep the MSB bytes 73#endif 74#if _BYTE_ORDER == _LITTLE_ENDIAN 75 REG_SLLV a2, a2, a3 # we want to keep the LSB bytes 76#endif 77 nor a2, zero, a2 # complement the mask 78 REG_L v0, -SZREG(a0) # load the word to partially clear 79 and v0, v0, a2 # clear the bytes 80 REG_S v0, -SZREG(a0) # store it back 81#endif |
| 631: | 821: |
| 64 and v0, a1, 3 # compute number of words left 65 subu a3, a1, v0 66 move a1, v0 67 addu a3, a3, a0 # compute ending address | 83 and v0, a1, SZREG-1 # compute number of words left 84 PTR_SUBU a3, a1, v0 85 move a1, v0 86 PTR_ADDU a3, a3, a0 # compute ending address |
| 682: | 872: |
| 69 addu a0, a0, 4 # clear words 70 bne a0, a3, 2b # unrolling loop doesnt help 71 sw zero, -4(a0) # since we are limited by memory speed | 88 PTR_ADDU a0, a0, SZREG # clear words 89 bne a0, a3, 2b # unrolling loop doesnt help 90 REG_S zero, -SZREG(a0) # since we are limited by memory speed |
| 72smallclr: | 91smallclr: |
| 73 ble a1, zero, 2f 74 addu a3, a1, a0 # compute ending address | 92 ble a1, zero, 2f 93 PTR_ADDU a3, a1, a0 # compute ending address |
| 751: | 941: |
| 76 addu a0, a0, 1 # clear bytes 77 bne a0, a3, 1b 78 sb zero, -1(a0) | 95 PTR_ADDU a0, a0, 1 # clear bytes 96 bne a0, a3, 1b 97 sb zero, -1(a0) |
| 792: | 982: |
| 80 j ra | 99 j ra |
| 81 nop 82END(bzero) | 100 nop 101END(bzero) |