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From: Julia Lawall <julia.lawall@lip6.fr>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>,
	Gilles Muller <Gilles.Muller@lip6.fr>,
	Nicolas Palix <nicolas.palix@imag.fr>,
	linux-kernel@vger.kernel.org, cocci@systeme.lip6.fr
Subject: [PATCH v2] coccinelle: orplus: reorganize to improve performance
Date: Mon, 13 Nov 2017 06:53:35 +0100 (CET)	[thread overview]
Message-ID: <alpine.DEB.2.20.1711130649370.2483@hadrien> (raw)

Adding two #define constants is less common than performing & and |
operations on them, so put the addition first to reduce the set of cases
that have to be considered in detail.  At the same time, add & and |
patterns for both arguments of +, to account for commutativity and obtain
more results.

Running time is divided by 3 when applying this to the whole kernel on my
laptop with an Intel i5-6200U CPU.

Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>

---

v2: added SOB and fixed typos in the commit message

diff --git a/scripts/coccinelle/misc/orplus.cocci b/scripts/coccinelle/misc/orplus.cocci
index 81fabf3..08de5be 100644
--- a/scripts/coccinelle/misc/orplus.cocci
+++ b/scripts/coccinelle/misc/orplus.cocci
@@ -14,7 +14,19 @@ virtual report
 virtual context

 @r@
-constant c;
+constant c,c1;
+identifier i,i1;
+position p;
+@@
+
+(
+ c1 + c - 1
+|
+ c1@i1 +@p c@i
+)
+
+@s@
+constant r.c, r.c1;
 identifier i;
 expression e;
 @@
@@ -27,28 +39,31 @@ e & c@i
 e |= c@i
 |
 e &= c@i
+|
+e | c1@i
+|
+e & c1@i
+|
+e |= c1@i
+|
+e &= c1@i
 )

-@s@
-constant r.c,c1;
-identifier i1;
-position p;
+@depends on s@
+position r.p;
+constant c1,c2;
 @@

-(
- c1 + c - 1
-|
-*c1@i1 +@p c
-)
+* c1 +@p c2

-@script:python depends on org@
-p << s.p;
+@script:python depends on s && org@
+p << r.p;
 @@

 cocci.print_main("sum of probable bitmasks, consider |",p)

-@script:python depends on report@
-p << s.p;
+@script:python depends on s && report@
+p << r.p;
 @@

 msg = "WARNING: sum of probable bitmasks, consider |"

             reply	other threads:[~2017-11-13  5:53 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-13  5:53 Julia Lawall [this message]
2017-11-16  0:03 ` Masahiro Yamada

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