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![Mao Zhongyi](/assets/img/avatar_default.png)
POSIX requires $PWD to be reliable, and we expect all shells used by qemu scripts to be relatively close to POSIX. Thus, it is smarter to avoid forking the pwd executable for something that is already available in the environment. So replace it with the following: sed -i 's/\(`pwd`\|\$(pwd)\)/$PWD/g' $(git grep -l pwd) Then delete a pointless line assigning PWD to itself. Cc: kwolf@redhat.com Cc: mreitz@redhat.com Cc: eblake@redhat.com Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com> Message-Id: <20181024094051.4470-2-maozhongyi@cmss.chinamobile.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: touch up commit message, reorder series, tweak a couple more files] Signed-off-by: Eric Blake <eblake@redhat.com>
108 lines
2.9 KiB
Plaintext
108 lines
2.9 KiB
Plaintext
// optimize TCG using extract op
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//
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// Copyright: (C) 2017 Philippe Mathieu-Daudé. GPLv2+.
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// Confidence: High
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// Options: --macro-file scripts/cocci-macro-file.h
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//
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// Nikunj A Dadhania optimization:
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// http://lists.nongnu.org/archive/html/qemu-devel/2017-02/msg05211.html
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// Aurelien Jarno optimization:
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// http://lists.nongnu.org/archive/html/qemu-devel/2017-05/msg01466.html
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//
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// This script can be run either using spatch locally or via a docker image:
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//
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// $ spatch \
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// --macro-file scripts/cocci-macro-file.h \
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// --sp-file scripts/coccinelle/tcg_gen_extract.cocci \
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// --keep-comments --in-place \
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// --use-gitgrep --dir target
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//
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// $ docker run --rm -v $PWD:$PWD -w $PWD philmd/coccinelle \
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// --macro-file scripts/cocci-macro-file.h \
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// --sp-file scripts/coccinelle/tcg_gen_extract.cocci \
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// --keep-comments --in-place \
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// --use-gitgrep --dir target
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@initialize:python@
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@@
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import sys
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fd = sys.stderr
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def debug(msg="", trailer="\n"):
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fd.write("[DBG] " + msg + trailer)
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def low_bits_count(value):
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bits_count = 0
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while (value & (1 << bits_count)):
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bits_count += 1
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return bits_count
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def Mn(order): # Mersenne number
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return (1 << order) - 1
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@match@
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identifier ret;
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metavariable arg;
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constant ofs, msk;
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position shr_p, and_p;
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@@
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(
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tcg_gen_shri_i32@shr_p
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tcg_gen_shri_i64@shr_p
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tcg_gen_shri_tl@shr_p
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)(ret, arg, ofs);
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... WHEN != ret
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(
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tcg_gen_andi_i32@and_p
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tcg_gen_andi_i64@and_p
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tcg_gen_andi_tl@and_p
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)(ret, ret, msk);
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@script:python verify_len depends on match@
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ret_s << match.ret;
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msk_s << match.msk;
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shr_p << match.shr_p;
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extract_len;
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@@
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is_optimizable = False
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debug("candidate at %s:%s" % (shr_p[0].file, shr_p[0].line))
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try: # only eval integer, no #define like 'SR_M' (cpp did this, else some headers are missing).
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msk_v = long(msk_s.strip("UL"), 0)
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msk_b = low_bits_count(msk_v)
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if msk_b == 0:
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debug(" value: 0x%x low_bits: %d" % (msk_v, msk_b))
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else:
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debug(" value: 0x%x low_bits: %d [Mersenne number: 0x%x]" % (msk_v, msk_b, Mn(msk_b)))
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is_optimizable = Mn(msk_b) == msk_v # check low_bits
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coccinelle.extract_len = "%d" % msk_b
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debug(" candidate %s optimizable" % ("IS" if is_optimizable else "is NOT"))
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except:
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debug(" ERROR (check included headers?)")
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cocci.include_match(is_optimizable)
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debug()
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@replacement depends on verify_len@
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identifier match.ret;
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metavariable match.arg;
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constant match.ofs, match.msk;
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position match.shr_p, match.and_p;
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identifier verify_len.extract_len;
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@@
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(
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-tcg_gen_shri_i32@shr_p(ret, arg, ofs);
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+tcg_gen_extract_i32(ret, arg, ofs, extract_len);
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... WHEN != ret
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-tcg_gen_andi_i32@and_p(ret, ret, msk);
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-tcg_gen_shri_i64@shr_p(ret, arg, ofs);
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+tcg_gen_extract_i64(ret, arg, ofs, extract_len);
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... WHEN != ret
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-tcg_gen_andi_i64@and_p(ret, ret, msk);
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-tcg_gen_shri_tl@shr_p(ret, arg, ofs);
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+tcg_gen_extract_tl(ret, arg, ofs, extract_len);
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... WHEN != ret
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-tcg_gen_andi_tl@and_p(ret, ret, msk);
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)
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