[LLVMdev] strange dbgs() behavior: unable to print floats in machine backend
Craig Topper
craig.topper at gmail.com
Tue Nov 27 13:48:20 PST 2012
The explicit fix was just to prevent the build from succeeding and doing
something unexpected. raw_ostream.h isn't automatically included everywhere
so its not unexpected that you would need to include to print in a file
that wasn't previously printing.
On Tue, Nov 27, 2012 at 1:38 AM, Bjorn De Sutter <
bjorn.desutter at elis.ugent.be> wrote:
> Hi Craig,
>
> I updated from the trunk some minutes ago, and thus got the "explicit".
> PrintReg constructor. When I do not include raw_ostream.h after including
> Debug.h in the backend cpp files, I now get compilation errors, not only
> when trying to print floats but also in other places. For example, for the
> code
>
> bool ADRESRegisterInfo::hasReservedCallFrame(const MachineFunction &MF)
> const {
> dbgs() << "hasReservedCallFrame() = " <<
> !MF.getFrameInfo()->hasVarSizedObjects() << "\n";
> return !MF.getFrameInfo()->hasVarSizedObjects();
> }
>
> I get
>
> llvm[0]: Compiling ADRESRegisterInfo.cpp for Debug+Asserts build
> /work/llvm/trunk/llvm/lib/Target/ADRES/ADRESRegisterInfo.cpp: In member
> function 'bool llvm::ADRESRegisterInfo::hasReservedCallFrame(const
> llvm::MachineFunction&) const':
> /work/llvm/trunk/llvm/lib/Target/ADRES/ADRESRegisterInfo.cpp:38:83: error:
> no match for 'operator<<' in 'llvm::operator<<((* & llvm::dbgs()), (* &
> llvm::Twine(((const char*)"hasReservedCallFrame() = ")))) << !(&
> MF)->llvm::MachineFunction::getFrameInfo()->llvm::MachineFrameInfo::hasVarSizedObjects()'
> /work/llvm/trunk/llvm/lib/Target/ADRES/ADRESRegisterInfo.cpp:38:83: note:
> candidates are:
> /work/llvm/trunk/llvm/include/llvm/Type.h:412:28: note: llvm::raw_ostream&
> llvm::operator<<(llvm::raw_ostream&, llvm::Type&)
> /work/llvm/trunk/llvm/include/llvm/Type.h:412:28: note: no known
> conversion for argument 2 from 'bool' to 'llvm::Type&'
> /work/llvm/trunk/llvm/include/llvm/ADT/Twine.h:516:23: note:
> llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const llvm::Twine&)
> /work/llvm/trunk/llvm/include/llvm/ADT/Twine.h:516:23: note: no known
> conversion for argument 2 from 'bool' to 'const llvm::Twine&'
> /work/llvm/trunk/llvm/include/llvm/CodeGen/MachineOperand.h:685:21: note:
> llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const
> llvm::MachineOperand&)
> /work/llvm/trunk/llvm/include/llvm/CodeGen/MachineOperand.h:685:21: note:
> no known conversion for argument 2 from 'bool' to 'const
> llvm::MachineOperand&'
> /work/llvm/trunk/llvm/include/llvm/Value.h:320:21: note:
> llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const llvm::Value&)
> /work/llvm/trunk/llvm/include/llvm/Value.h:320:21: note: no known
> conversion for argument 2 from 'bool' to 'const llvm::Value&'
> /work/llvm/trunk/llvm/include/llvm/CodeGen/MachineInstr.h:1017:21: note:
> llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const
> llvm::MachineInstr&)
> /work/llvm/trunk/llvm/include/llvm/CodeGen/MachineInstr.h:1017:21: note:
> no known conversion for argument 2 from 'bool' to 'const
> llvm::MachineInstr&'
> /work/llvm/trunk/llvm/include/llvm/CodeGen/MachineBasicBlock.h:621:14:
> note: llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const
> llvm::MachineBasicBlock&)
> /work/llvm/trunk/llvm/include/llvm/CodeGen/MachineBasicBlock.h:621:14:
> note: no known conversion for argument 2 from 'bool' to 'const
> llvm::MachineBasicBlock&'
> /work/llvm/trunk/llvm/include/llvm/Target/TargetRegisterInfo.h:885:28:
> note: llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const
> llvm::PrintReg&)
> /work/llvm/trunk/llvm/include/llvm/Target/TargetRegisterInfo.h:885:28:
> note: no known conversion for argument 2 from 'bool' to 'const
> llvm::PrintReg&'
> /work/llvm/trunk/llvm/include/llvm/Target/TargetRegisterInfo.h:908:28:
> note: llvm::raw_ostream& llvm::operator<<(llvm::raw_ostream&, const
> llvm::PrintRegUnit&)
> /work/llvm/trunk/llvm/include/llvm/Target/TargetRegisterInfo.h:908:28:
> note: no known conversion for argument 2 from 'bool' to 'const
> llvm::PrintRegUnit&'
>
>
> Including the raw_ostream.h fixes this, but that is not a thing I should
> have to do, right?
>
> Best,
>
> Bjorn
>
>
>
>
> On 27 Nov 2012, at 09:05, Craig Topper <craig.topper at gmail.com> wrote:
>
> Can you try making the constructor "explicit" for PrintReg in
> include/llvm/Target/TargetRegisterInfo.h. I think you were getting an
> implicit conversion there which should probably be fixed anyway.
>
> On Mon, Nov 26, 2012 at 11:47 PM, Bjorn De Sutter <
> bjorn.desutter at elis.ugent.be> wrote:
>
>> Hi,
>>
>> that solved my problem on trunk as well, thanks. Strange that you have to
>> include this though.
>>
>> Bjorn
>>
>> On 27 Nov 2012, at 00:00, Daniel Prokesch <daniel.prokesch at gmail.com>
>> wrote:
>>
>> > Hi,
>> >
>> > I accidentally stumbled upon your post.
>> > I observed similar behaviour whenever I did not include
>> >
>> > #include "llvm/Support/Debug.h"
>> > #include "llvm/Support/raw_ostream.h"
>> >
>> > I'm working on release 3.1 though.
>> >
>> > hth, Daniel
>> >
>> > On 11/26/2012 03:00 PM, Bjorn De Sutter wrote:
>> >> Hi,
>> >>
>> >> I am trying to debug my backend, and observe very strange behavior
>> with dbgs():
>> >>
>> >> In the IfConverter, I have added two debugging lines that print
>> floating-point numbers for the sake of demonstration that such printing
>> works fine.
>> >>
>> >> bool MeetIfcvtSizeLimit(MachineBasicBlock &BB,
>> >> unsigned Cycle, unsigned Extra,
>> >> const BranchProbability &Prediction) const
>> {
>> >>
>> >> dbgs() << "OOPS " << 1.14 << "\n";
>> >> bool flag = Cycle > 0 && TII->isProfitableToIfCvt(BB,
>> Cycle, Extra,
>> >> Prediction);
>> >> dbgs() << "OOPS " << 1.15 << "\n";
>> >> return flag;
>> >> }
>> >>
>> >> This method invokes the backend method
>> >>
>> >> bool ADRESInstrInfo::isProfitableToIfCvt(MachineBasicBlock &MBB,
>> unsigned NumCycles, unsigned ExtraPredCycles,
>> >> const BranchProbability
>> &Probability) const {
>> >> dbgs() << "OOPS " << 1.16 << "\n";
>> >> }
>> >>
>> >> This invocation works as it should (verified with gdb). But when I
>> execute this code fragment, I get
>> >>
>> >> OOPS 1.140000e+00
>> >> OOPS %physreg1
>> >> OOPS 1.150000e+00
>> >>
>> >> So suddenly in the machine backend, the dbgs() ostream (which is still
>> the very same ostream as in the IfConverter, I checked the address with
>> gdb) prints floating point numbers as if they are physical registers. Any
>> idea what is going on or how I can force floating-point numbers to be
>> printed in the backend code? I want to do that to tune my if-predication
>> heuristics ...
>> >>
>> >> By the way, when I step through the isProfitableToIfCvt method, rather
>> than invoking a <<-operator in an ostream class, the constructor of the
>> Twine class is invoked ...
>> >>
>> >> Thanks,
>> >>
>> >> Bjorn De Sutter
>> >> Computer Systems Lab
>> >> Ghent University
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> LLVM Developers mailing list
>> >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
>> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
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>>
>
>
>
> --
> ~Craig
>
>
>
--
~Craig
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