/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
*/
/*
* char *memset(sp, c, n)
*
* Set an array of n chars starting at sp to the character c.
* Return sp.
*
* Fast assembler language version of the following C-program for memset
* which represents the `standard' for the C-library.
*
* void *
* memset(void *sp1, int c, size_t n)
* {
* if (n != 0) {
* char *sp = sp1;
* do {
* *sp++ = (char)c;
* } while (--n != 0);
* }
* return (sp1);
* }
*/
#include <sys/asm_linkage.h>
.section ".text"
.align 32
.wrchar:
retl
.empty ! next instruction is safe, %o0 still good
.wrbig:
andcc %o5, 7, %o3 ! is sp1 aligned on a 8 byte bound
bz,pt %ncc, .blkchk ! already double aligned
and %o1, 0xff, %o1 ! o1 is (char)c
sub %o3, 8, %o3 ! -(bytes till double aligned)
add %o2, %o3, %o2 ! update o2 with new count
! Set -(%o3) bytes till sp1 double aligned
1: stb %o1, [%o5] ! there is at least 1 byte to set
inccc %o3 ! byte clearing loop
bl,pt %ncc, 1b
inc %o5
! Now sp1 is double aligned (sp1 is found in %o5)
.blkchk:
sll %o1, 8, %o3
or %o1, %o3, %o1 ! now o1 has 2 bytes of c
sll %o1, 16, %o3
or %o1, %o3, %o1 ! now o1 has 4 bytes of c
sllx %o1, 32, %o3
or %o1, %o3, %o1 ! now o1 has 8 bytes of c
bgu,a,pn %ncc, .blkwr ! Do block write for large count
andcc %o5, 63, %o3 ! is sp1 block aligned?
and %o2, 24, %o3 ! o3 is {0, 8, 16, 24}
1: subcc %o3, 8, %o3 ! double-word loop
add %o5, 8, %o5
bgeu,a,pt %ncc, 1b
stx %o1, [%o5 - 8] ! already incremented the address
andncc %o2, 31, %o4 ! o4 has 32 byte aligned count
bz,pn %ncc, 3f ! First instruction of icache line
2:
subcc %o4, 32, %o4 ! main loop, 32 bytes per iteration
stx %o1, [%o5 - 8]
stx %o1, [%o5]
stx %o1, [%o5 + 8]
stx %o1, [%o5 + 16]
bnz,pt %ncc, 2b
add %o5, 32, %o5
3:
and %o2, 7, %o2 ! o2 has the remaining bytes (<8)
4:
deccc %o2 ! byte clearing loop
inc %o5
bgeu,a,pt %ncc, 4b
stb %o1, [%o5 - 9] ! already incremented the address
retl
nop ! %o0 still preserved
.blkwr:
bz,pn %ncc, .blalign ! now block aligned
sub %o3, 64, %o3 ! o3 is -(bytes till block aligned)
add %o2, %o3, %o2 ! o2 is the remainder
! Store -(%o3) bytes till dst is block (64 byte) aligned.
! Use double word stores.
! Recall that dst is already double word aligned
1:
stx %o1, [%o5]
addcc %o3, 8, %o3
bl,pt %ncc, 1b
add %o5, 8, %o5
! sp1 is block aligned
.blalign:
rd %fprs, %g1 ! g1 = fprs
and %o2, 63, %o3 ! calc bytes left after blk store.
andcc %g1, 0x4, %g1 ! fprs.du = fprs.dl = 0
bz,a %ncc, 2f ! Is fprs.fef == 0
wr %g0, 0x4, %fprs ! fprs.fef = 1
2:
brnz,pn %o1, 3f ! %o1 is safe to check all 64-bits
andn %o2, 63, %o4 ! calc size of blocks in bytes
fzero %d0
fzero %d2
fzero %d4
fzero %d6
fmuld %d0, %d0, %d8
fzero %d10
ba 4f
fmuld %d0, %d0, %d12
3:
! allocate 8 bytes of scratch space on the stack
add %sp, -SA(16), %sp
stx %o1, [%sp + STACK_BIAS + ALIGN8(MINFRAME)] ! move %o1 to %d0
ldd [%sp + STACK_BIAS + ALIGN8(MINFRAME)], %d0
fmovd %d0, %d2
add %sp, SA(16), %sp ! deallocate the scratch space
fmovd %d0, %d4
fmovd %d0, %d6
fmovd %d0, %d8
fmovd %d0, %d10
fmovd %d0, %d12
4:
fmovd %d0, %d14
! 1st quadrant has 64 bytes of c
! instructions 32-byte aligned here
stda %d0, [%o5]ASI_BLK_P
subcc %o4, 64, %o4
bgu,pt %ncc, 4b
add %o5, 64, %o5
! Set the remaining doubles
subcc %o3, 8, %o3 ! Can we store any doubles?
blu,pn %ncc, 6f
and %o2, 7, %o2 ! calc bytes left after doubles
5:
std %d0, [%o5] ! store the doubles
subcc %o3, 8, %o3
bgeu,pt %ncc, 5b
add %o5, 8, %o5
6:
! Set the remaining bytes
brz %o2, .exit ! safe to check all 64-bits
#if 0
! Terminate the copy with a partial store. (bug 1200071 does not apply)
! The data should be at d0
dec %o2 ! needed to get the mask right
edge8n %g0, %o2, %o4
stda %d0, [%o5]%o4, ASI_PST8_P
#else
7:
deccc %o2
stb %o1, [%o5]
bgu,pt %ncc, 7b
inc %o5
#endif
.exit:
membar #StoreLoad|#StoreStore
retl ! %o0 was preserved
wr %g1, %g0, %fprs ! fprs = g1 restore fprs
SET_SIZE(memset)