Hello, how to get the numerical value of an constant operand? For ex. %tmp mul i32 %indvar, 6 , in this instruction second operand is a numerical constant with value 6. But i am only able to print it by using getOperand(1), not able to store it in any integer variable. Using getName() returns a empty string. Is there any way to solve this problem? Thank you. John Criswell-2 wrote:> > help__me_please wrote: >> Can you please give an example of creating an instruction (for example >> add >> instructions with two operand a and b)? I am trying instruction() for a >> while, but no success yet. >> > > You need to look for the appropriate subclass of llvm::Instruction and > find the method for creating a new instruction. The method is usually a > static method and takes arguments pointing to the values to use as > operands. Doxygen is your best resource for finding these methods. > > For example, if you look at > http://llvm.org/doxygen/classllvm_1_1AllocaInst.html, you can see that > the AllocaInst class (which represents an alloca instruction) has a > standard constructor method that takes the type of object to allocate, > the name of the new alloca instruction, an instruction before which to > insert the alloca instruction, etc. > > As another example, the CallInst class > (http://llvm.org/doxygen/classllvm_1_1CallInst.html) represents a call > instruction and has a static Create() method that you can use to create > a new call instruction. > > -- John T. > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > >-- View this message in context: http://old.nabble.com/Operand%2C-instruction-tp21961718p28329007.html Sent from the LLVM - Dev mailing list archive at Nabble.com.
Hi Ben,> if (ConstantInt *c = (ConstantInt *) dyn_cast<ConstantInt>(index)){ > errs()<< "And it's a constant!!!!!!1111oneone!! ("<<c->getZExtValue() > << ")\n"; > }I don't think you need the "(ConstantInt *)" cast. The getZExtValue will fail if the constant doesn't fit in 64 bits. Ciao, Duncan.
if (ConstantInt *c = (ConstantInt *) dyn_cast<ConstantInt>(index)){
errs() << "And it's a constant!!!!!!1111oneone!! ("
<<c->getZExtValue()
<< ")\n";
}
--
"Believe you can, believe you can't; either way you're right."
-Henry Ford
-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of help__me_please
Sent: Thursday, April 22, 2010 8:38 AM
To: llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] Operand, instruction
Hello, how to get the numerical value of an constant operand? For ex. %tmp mul
i32 %indvar, 6 , in this instruction second operand is a numerical
constant with value 6. But i am only able to print it by using
getOperand(1), not able to store it in any integer variable. Using getName()
returns a empty string. Is there any way to solve this problem?
Thank you.
John Criswell-2 wrote:>
> help__me_please wrote:
>> Can you please give an example of creating an instruction (for example
>> add
>> instructions with two operand a and b)? I am trying instruction() for a
>> while, but no success yet.
>>
>
> You need to look for the appropriate subclass of llvm::Instruction and
> find the method for creating a new instruction. The method is usually a
> static method and takes arguments pointing to the values to use as
> operands. Doxygen is your best resource for finding these methods.
>
> For example, if you look at
> http://llvm.org/doxygen/classllvm_1_1AllocaInst.html, you can see that
> the AllocaInst class (which represents an alloca instruction) has a
> standard constructor method that takes the type of object to allocate,
> the name of the new alloca instruction, an instruction before which to
> insert the alloca instruction, etc.
>
> As another example, the CallInst class
> (http://llvm.org/doxygen/classllvm_1_1CallInst.html) represents a call
> instruction and has a static Create() method that you can use to create
> a new call instruction.
>
> -- John T.
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
--
View this message in context:
http://old.nabble.com/Operand%2C-instruction-tp21961718p28329007.html
Sent from the LLVM - Dev mailing list archive at Nabble.com.
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Thanks for the quick reply. I am able to get the numerical value. But i also need the numerical value to be in value type, so that it can be used as operand of other instruction. For that i am trying to create a new ConstantInt, but i am unable to find create() function for ConstantInt. Thanks again for the quick and helpful reply. Ben Perry-3 wrote:> > if (ConstantInt *c = (ConstantInt *) dyn_cast<ConstantInt>(index)){ > errs() << "And it's a constant!!!!!!1111oneone!! (" <<c->getZExtValue() > << ")\n"; > } > > -- > "Believe you can, believe you can't; either way you're right." -Henry > Ford > > > -----Original Message----- > From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On > Behalf Of help__me_please > Sent: Thursday, April 22, 2010 8:38 AM > To: llvmdev at cs.uiuc.edu > Subject: Re: [LLVMdev] Operand, instruction > > > Hello, how to get the numerical value of an constant operand? For ex. %tmp > > mul i32 %indvar, 6 , in this instruction second operand is a numerical > constant with value 6. But i am only able to print it by using > getOperand(1), not able to store it in any integer variable. Using > getName() > returns a empty string. Is there any way to solve this problem? > Thank you. > > John Criswell-2 wrote: >> >> help__me_please wrote: >>> Can you please give an example of creating an instruction (for example >>> add >>> instructions with two operand a and b)? I am trying instruction() for a >>> while, but no success yet. >>> >> >> You need to look for the appropriate subclass of llvm::Instruction and >> find the method for creating a new instruction. The method is usually a >> static method and takes arguments pointing to the values to use as >> operands. Doxygen is your best resource for finding these methods. >> >> For example, if you look at >> http://llvm.org/doxygen/classllvm_1_1AllocaInst.html, you can see that >> the AllocaInst class (which represents an alloca instruction) has a >> standard constructor method that takes the type of object to allocate, >> the name of the new alloca instruction, an instruction before which to >> insert the alloca instruction, etc. >> >> As another example, the CallInst class >> (http://llvm.org/doxygen/classllvm_1_1CallInst.html) represents a call >> instruction and has a static Create() method that you can use to create >> a new call instruction. >> >> -- John T. >> >> >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >> >> > > -- > View this message in context: > http://old.nabble.com/Operand%2C-instruction-tp21961718p28329007.html > Sent from the LLVM - Dev mailing list archive at Nabble.com. > > _______________________________________________ > 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 > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > >-- View this message in context: http://old.nabble.com/Operand%2C-instruction-tp21961718p28331688.html Sent from the LLVM - Dev mailing list archive at Nabble.com.