Sync with libc: use bzero-based assembly version of memset().
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kleink
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@ -1,10 +1,10 @@
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# $NetBSD: Makefile.inc,v 1.26 2000/11/01 19:37:20 thorpej Exp $
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# $NetBSD: Makefile.inc,v 1.27 2001/07/01 11:55:36 kleink Exp $
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SRCS+= __main.c __assert.c \
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imax.c imin.c lmax.c lmin.c max.c min.c ulmax.c ulmin.c \
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bswap16.c bswap32.c bswap64.c \
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bcmp.c bzero.S ffs.S \
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memchr.c memcmp.c memset.c \
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memchr.c memcmp.c memset.S \
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strcat.c strcmp.c strcpy.c strlen.S strcasecmp.c \
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strncasecmp.c strncmp.c strncpy.c \
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scanc.c skpc.c \
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@ -1,4 +1,4 @@
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/* $NetBSD: bzero.S,v 1.5 1999/03/05 09:18:32 pk Exp $ */
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/* $NetBSD: bzero.S,v 1.6 2001/07/01 11:55:36 kleink Exp $ */
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/*
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* Copyright (c) 1992, 1993
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@ -44,32 +44,61 @@
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#if 0
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.asciz "@(#)bzero.s 8.1 (Berkeley) 6/4/93"
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#else
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RCSID("$NetBSD: bzero.S,v 1.5 1999/03/05 09:18:32 pk Exp $")
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RCSID("$NetBSD: bzero.S,v 1.6 2001/07/01 11:55:36 kleink Exp $")
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#endif
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#endif /* LIBC_SCCS and not lint */
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/*
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* bzero(addr, len)
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*
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* We should unroll the loop, but at the moment this would
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* gain nothing since the `std' instructions are what limits us.
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*/
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#ifdef MEMSET
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/*
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* void *
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* memset(void *addr, int pattern, size_t len)
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*/
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ENTRY(memset)
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! %o0 = addr, %o1 = pattern, %o2 = len
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/*
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* Expand the byte pattern to fill 64 bits in an even-aligned
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* register pair; shuffle arguments to match those of bzero.
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*/
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and %o1, 0xff, %o3
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mov %o2, %o1 ! shuffle argument
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sll %o3, 8, %o2
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or %o2, %o3, %o2
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mov %o0, %g1 ! save original pointer
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sll %o2, 16, %o3
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or %o2, %o3, %o2
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! Optimize a common case: addr and len are both multiples of 8.
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or %o0, %o1, %o5
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btst 7, %o5 ! ((addr | len) & 7) != 0?
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bnz 1f ! if so, cannot optimize
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mov %o2, %o3 ! in any case, complete pat expansion
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#else
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/*
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* void
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* bzero(void *addr, size_t len)
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*/
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ENTRY(bzero)
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! %o0 = addr, %o1 = len
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clr %o2
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! Optimize a common case: addr and len are both multiples of 8.
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or %o0, %o1, %o2
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btst 7, %o2 ! ((addr | len) & 7) != 0?
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or %o0, %o1, %o5
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btst 7, %o5 ! ((addr | len) & 7) != 0?
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bnz 1f ! if so, cannot optimize
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clr %g1 ! in any case, we want g1=0
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clr %o3 ! in any case, we want o3=0
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#endif
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/* `Good' operands, can just store doubles. */
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0:
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deccc 8, %o1 ! while ((len -= 8) >= 0)
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bge,a 0b
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std %g0, [%o0 + %o1] ! *(quad *)(addr + len) = 0;
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std %o2, [%o0 + %o1] ! *(quad *)(addr + len) = 0;
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retl
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nop
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nop
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/*
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* Either the address is unaligned, or the count is not a
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@ -85,7 +114,7 @@ ENTRY(bzero)
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2:
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deccc %o1 ! while (--len >= 0)
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bge,a 2b
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stb %g0, [%o0 + %o1] ! addr[len] = 0;
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stb %o2, [%o0 + %o1] ! addr[len] = 0;
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retl
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nop
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@ -97,21 +126,21 @@ Lstd:
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*/
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bz,a 1f ! if (addr & 1) {
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btst 2, %o0
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stb %g0, [%o0] ! *addr = 0;
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stb %o2, [%o0] ! *addr = 0;
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inc %o0 ! addr++;
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dec %o1 ! len--;
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btst 2, %o0 ! }
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1:
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bz,a 1f ! if (addr & 2) {
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btst 4, %o0
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sth %g0, [%o0] ! *(short *)addr = 0;
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sth %o2, [%o0] ! *(short *)addr = 0;
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inc 2, %o0 ! addr += 2;
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dec 2, %o1 ! len -= 2;
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btst 4, %o0 ! }
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1:
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bz 1f ! if (addr & 4) {
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dec 8, %o1
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st %g0, [%o0] ! *(int *)addr = 0;
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st %o2, [%o0] ! *(int *)addr = 0;
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inc 4, %o0 ! addr += 4;
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dec 4, %o1 ! len -= 4;
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! }
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@ -121,12 +150,12 @@ Lstd:
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* the remaining count is 8, 1 if it is 9, etc.).
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*/
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1:
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std %g0, [%o0] ! do {
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std %o2, [%o0] ! do {
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2: ! *(quad *)addr = 0;
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inc 8, %o0 ! addr += 8;
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deccc 8, %o1 ! } while ((len -= 8) >= 0);
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bge,a 2b
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std %g0, [%o0]
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std %o2, [%o0]
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/*
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* Len is in [-8..-1] where -8 => done, -7 => 1 byte to zero,
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@ -135,16 +164,20 @@ Lstd:
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btst 4, %o1
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bz 1f ! if (len & 4) {
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btst 2, %o1
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st %g0, [%o0] ! *(int *)addr = 0;
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st %o2, [%o0] ! *(int *)addr = 0;
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inc 4, %o0 ! addr += 4;
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1:
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bz 1f ! if (len & 2) {
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btst 1, %o1
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sth %g0, [%o0] ! *(short *)addr = 0;
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sth %o2, [%o0] ! *(short *)addr = 0;
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inc 2, %o0 ! addr += 2;
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1:
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bnz,a 1f ! if (len & 1)
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stb %g0, [%o0] ! *addr = 0;
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stb %o2, [%o0] ! *addr = 0;
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1:
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retl
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#ifdef MEMSET
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mov %g1, %o0 ! restore original pointer
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#else
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nop
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#endif
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@ -0,0 +1,4 @@
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/* $NetBSD: memset.S,v 1.1 2001/07/01 11:55:36 kleink Exp $ */
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#define MEMSET
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#include "bzero.S"
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