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Remove bzero().

This commit is contained in:
mycroft 1995-10-07 22:24:50 +00:00
parent be0a951c76
commit 6287d3d7b2
1 changed files with 0 additions and 102 deletions
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102
sys/arch/sparc/sparc/locore.s
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@ -4132,108 +4132,6 @@ ENTRY(qzero)
retl
nop
/*
* bzero(addr, len)
*
* We should unroll the loop, but at the moment this would
* gain nothing since the `std' instructions are what limits us.
*/
ALTENTRY(blkclr)
ENTRY(bzero)
! %o0 = addr, %o1 = len
! Optimize a common case: addr and len are both multiples of 8.
or %o0, %o1, %o2
btst 7, %o2 ! ((addr | len) & 7) != 0?
bnz 1f ! if so, cannot optimize
clr %g1 ! in any case, we want g1=0
/* `Good' operands, can just store doubles. */
0:
deccc 8, %o1 ! while ((len -= 8) >= 0)
bge,a 0b
std %g0, [%o0 + %o1] ! *(quad *)(addr + len) = 0;
retl
nop
/*
* Either the address is unaligned, or the count is not a
* multiple of 8, or both. We will have to align the address
* in order to use anything `better' than stb.
*/
1:
cmp %o1, 15 ! len >= 15?
bge,a Lstd ! yes, use std
btst 1, %o0 ! (but first check alignment)
! not enough to bother: do byte-at-a-time loop.
2:
deccc %o1 ! while (--len >= 0)
bge,a 2b
stb %g0, [%o0 + %o1] ! addr[len] = 0;
retl
nop
Lstd:
/*
* There are at least 15 bytes to zero.
* We may have to zero some initial stuff to align
* the address.
*/
bz,a 1f ! if (addr & 1) {
btst 2, %o0
stb %g0, [%o0] ! *addr = 0;
inc %o0 ! addr++;
dec %o1 ! len--;
btst 2, %o0 ! }
1:
bz,a 1f ! if (addr & 2) {
btst 4, %o0
sth %g0, [%o0] ! *(short *)addr = 0;
inc 2, %o0 ! addr += 2;
dec 2, %o1 ! len -= 2;
btst 4, %o0 ! }
1:
bz 1f ! if (addr & 4) {
dec 8, %o1
st %g0, [%o0] ! *(int *)addr = 0;
inc 4, %o0 ! addr += 4;
dec 4, %o1 ! len -= 4;
! }
/*
* Address is double word aligned; len is 8 less than
* the number of bytes remaining (i.e., len is 0 if
* the remaining count is 8, 1 if it is 9, etc.).
*/
1:
std %g0, [%o0] ! do {
2: ! *(quad *)addr = 0;
inc 8, %o0 ! addr += 8;
deccc 8, %o1 ! } while ((len -= 8) >= 0);
bge,a 2b
std %g0, [%o0]
/*
* Len is in [-8..-1] where -8 => done, -7 => 1 byte to zero,
* -6 => two bytes, etc. Mop up this remainder, if any.
*/
btst 4, %o1
bz 1f ! if (len & 4) {
btst 2, %o1
st %g0, [%o0] ! *(int *)addr = 0;
inc 4, %o0 ! addr += 4;
1:
bz 1f ! if (len & 2) {
btst 1, %o1
sth %g0, [%o0] ! *(short *)addr = 0;
inc 2, %o0 ! addr += 2;
1:
bnz,a 1f ! if (len & 1)
stb %g0, [%o0] ! *addr = 0;
1:
retl
nop
/*
* kernel bcopy/memcpy
* Assumes regions do not overlap; has no useful return value.