From: LIU Hao <lh_mouse@126.com>
To: stefan@franke.ms, gcc-help@gcc.gnu.org
Subject: Re: AW: optimizer discards sign information
Date: Wed, 10 Apr 2024 17:57:14 +0800 [thread overview]
Message-ID: <20096916-dc47-4cc9-93c1-bc910ef07327@126.com> (raw)
In-Reply-To: <018d01da8b2c$59e89e90$0db9dbb0$@franke.ms>
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在 2024-04-10 17:49, stefan@franke.ms 写道:
> But I keep considering this as a bug. And clang behaves correctly!
Yes there have been many reports [1]. It's a missed optimization.
You may work around it by using 32-bit parameters, or casting either operand to u32; casting the
result will not help.
[1]
https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=SUSPENDED&bug_status=WAITING&bug_status=REOPENED&cf_gcctarget=x86_64&cf_gcctarget_type=allwordssubstr&cf_known_to_fail_type=allwords&cf_known_to_work_type=allwords&f0=OP&f1=OP&f2=product&f3=component&f4=alias&f5=short_desc&f7=content&f8=CP&f9=CP&j1=OR&list_id=423756&o2=substring&o3=substring&o4=substring&o5=substring&o6=substring&o7=matches&query_format=advanced&short_desc=sign%20extension&short_desc_type=allwordssubstr&v2=sign-extension&v3=sign-extension&v4=sign-extension&v5=sign-extension&v6=sign-extension&v7="sign-extension"
--
Best regards,
LIU Hao
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next prev parent reply other threads:[~2024-04-10 9:57 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-10 8:52 stefan
2024-04-10 9:16 ` Alexander Monakov
2024-04-10 9:19 ` Xi Ruoyao
2024-04-10 9:40 ` LIU Hao
2024-04-10 9:44 ` Xi Ruoyao
2024-04-10 9:51 ` LIU Hao
2024-04-10 9:52 ` Xi Ruoyao
2024-04-10 10:07 ` LIU Hao
2024-04-10 10:17 ` Xi Ruoyao
2024-04-10 10:03 ` AW: " stefan
2024-04-10 10:34 ` Xi Ruoyao
2024-04-10 9:24 ` stefan
2024-04-10 9:49 ` stefan
2024-04-10 9:54 ` Xi Ruoyao
2024-04-10 9:57 ` LIU Hao [this message]
2024-04-10 10:03 ` Xi Ruoyao
2024-04-10 11:52 ` David Brown
2024-04-10 14:25 ` Stefan Franke
2024-04-10 16:51 ` David Brown
2024-04-11 0:32 ` Oleg Endo
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