From: "mjw at redhat dot com" <sourceware-bugzilla@sourceware.org>
To: systemtap@sources.redhat.com
Subject: [Bug translator/11590] New: optimized pre/postfix operators on variable throw away initial variable assignment
Date: Wed, 12 May 2010 13:08:00 -0000 [thread overview]
Message-ID: <20100512092821.11590.mjw@redhat.com> (raw)
The following testcase shows that the original assignment of the variable is
ignored:
probe begin {
a = 5
// printf("%d ", a)
printf("%d ", (a++))
printf("%d ", (++a))
printf("%d ", (a--))
printf("%d\n", (--a))
exit()
}
$ stap test.stp
0 2 2 0
If we uncomment the actually first use the original assigned value of a things
look correct:
$ stap test.stp
5 5 7 7 5
This is an translation optimization issue, the original script also prints out
the correct value when unoptimized:
$ stap -u test.stp
5 7 7 5
--
Summary: optimized pre/postfix operators on variable throw away
initial variable assignment
Product: systemtap
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: translator
AssignedTo: systemtap at sources dot redhat dot com
ReportedBy: mjw at redhat dot com
http://sourceware.org/bugzilla/show_bug.cgi?id=11590
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next reply other threads:[~2010-05-12 9:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-12 13:08 mjw at redhat dot com [this message]
2010-05-12 15:20 ` [Bug translator/11590] " mjw at redhat dot com
2010-05-12 15:24 ` mjw at redhat dot com
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