[llvm-commits] [llvm] r140624 - /llvm/trunk/lib/Target/PTX/PTXAsmPrinter.cpp

[Eli Friedman]

On Wed, Sep 28, 2011 at 4:58 AM, Justin Holewinski
<justin.holewinski at gmail.com> wrote:
> On Tue, Sep 27, 2011 at 4:01 PM, Eli Friedman <eli.friedman at gmail.com>
> wrote:
>>
>> On Tue, Sep 27, 2011 at 12:25 PM, Justin Holewinski
>> <justin.holewinski at gmail.com> wrote:
>> > Author: jholewinski
>> > Date: Tue Sep 27 14:25:49 2011
>> > New Revision: 140624
>> >
>> > URL: http://llvm.org/viewvc/llvm-project?rev=140624&view=rev
>> > Log:
>> > PTX: Fix case where printed alignment could be 0
>> >
>> > Modified:
>> >    llvm/trunk/lib/Target/PTX/PTXAsmPrinter.cpp
>> >
>> > Modified: llvm/trunk/lib/Target/PTX/PTXAsmPrinter.cpp
>> > URL:
>> > http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PTX/PTXAsmPrinter.cpp?rev=140624&r1=140623&r2=140624&view=diff
>> >
>> > ==============================================================================
>> > --- llvm/trunk/lib/Target/PTX/PTXAsmPrinter.cpp (original)
>> > +++ llvm/trunk/lib/Target/PTX/PTXAsmPrinter.cpp Tue Sep 27 14:25:49 2011
>> > @@ -480,7 +480,7 @@
>> >   unsigned alignment = gv->getAlignment();
>> >   if (alignment != 0) {
>> >     decl += ".align ";
>> > -    decl += utostr(Log2_32(gv->getAlignment()));
>> > +    decl += utostr(std::max(1U, Log2_32(gv->getAlignment())));
>> >     decl += " ";
>> >   }
>>
>> This looks wrong: you're making sure the alignment is at least 2 bytes?!
>
> No, this is making sure it is at least 1 byte. There were some cases where
> the Log2 function was returning 0.

log2(1) == 0.  log2(2) == 1.  Hence, your patch enforces a minimum
alignment of 2 bytes.

-Eli