Date: Fri, 19 Jan 2018 10:43:50 -0800 (PST) From: "Rodney W. Grimes" <freebsd@pdx.rh.CN85.dnsmgr.net> To: cem@freebsd.org Cc: John Baldwin <jhb@freebsd.org>, src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r328159 - head/sys/modules Message-ID: <201801191843.w0JIhoVS073408@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <CAG6CVpVSjSbOwM=ktSJAjfapVNTFeNpnfZ1tMy-2-MKu9Rsmuw@mail.gmail.com>
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[ Charset UTF-8 unsupported, converting... ] > On Fri, Jan 19, 2018 at 9:51 AM, John Baldwin <jhb@freebsd.org> wrote: > > On Friday, January 19, 2018 04:34:06 AM Conrad Meyer wrote: > >> The logical result of a right shift >= the width of a type is zero, but our > >> compiler decides this is a warning (and thus, error). Just remove ccp(4) > >> from i386. > > > > You would think that. The shift instructions on x86 effectively ignore the > > upper bits of the count, so a 33-bit shift on i386 ends up being a 1-bit shift, > > etc. IIRC. > > This never becomes a shift instruction on x86 or any other arch ? it's > a constant before it reaches machine code. A constant that is produce by a? Shift insturction perhaps? Ok, that was pedantically over kill, but is what most likely happens. -- Rod Grimes rgrimes@freebsd.org
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