blob: d257f1818152cae5b06efb76af89bf29ab058875 [file] [log] [blame]
/* Written by Richard P. Curnow, SuperH (UK) Ltd.
Tight version of memset for the case of just clearing a page. It turns out
that having the alloco's spaced out slightly due to the increment/branch
pair causes them to contend less for access to the cache. Similarly,
keeping the stores apart from the allocos causes less contention. => Do two
separate loops. Do multiple stores per loop to amortise the
increment/branch cost a little.
r2 : source effective address (start of page)
Always clears 4096 bytes.
.section .text..SHmedia32,"ax"
.balign 8
.global sh64_page_clear
pta/l 1f, tr1
pta/l 2f, tr2
ptabs/l r18, tr0
movi 4096, r7
add r2, r7, r7
add r2, r63, r6
alloco r6, 0
addi r6, 32, r6
bgt/l r7, r6, tr1
add r2, r63, r6
st.q r6, 0, r63
st.q r6, 8, r63
st.q r6, 16, r63
st.q r6, 24, r63
addi r6, 32, r6
bgt/l r7, r6, tr2
blink tr0, r63