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- /*
- Copyright 2003 Richard Curnow, SuperH (UK) Ltd.
- This file is subject to the terms and conditions of the GNU General Public
- License. See the file "COPYING" in the main directory of this archive
- for more details.
- 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.
- Parameters:
- r2 : source effective address (start of page)
- Always clears 4096 bytes.
- Note : alloco guarded by synco to avoid TAKum03020 erratum
- */
- .section .text..SHmedia32,"ax"
- .little
- .balign 8
- .global sh64_page_clear
- 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
- 1:
- alloco r6, 0
- synco ! TAKum03020
- addi r6, 32, r6
- bgt/l r7, r6, tr1
- add r2, r63, r6
- 2:
- 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
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