llvm dev - Sep 2008 - [LLVMdev] Determining the register type of a MachineOperand

This only has the register class information, not the register type
information.

 

My register class has multiple register types and I need to know how to
differentiate which register type of my register class of the current
register.

The information in the MVT data type is what I need, i.e. the position
in the GPRVT array of each register.

 

Something equivalent to MVT getValueType() but for registers.

 

Thanks,

 

________________________________

From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu]
On Behalf Of Evan Cheng
Sent: Wednesday, September 24, 2008 10:22 AM
To: LLVM Developers Mailing List
Subject: Re: [LLVMdev] Determining the register type of a MachineOperand

 

You can get to the MachineInstr from a MachineOperand. Then get to its
TargetInstrDesc and TargetOperandInfo which has register class
information.

 

Evan

 

On Sep 23, 2008, at 12:44 PM, Villmow, Micah wrote:





How do I determine what type of register(i.e. i32, f32, etc..) I am
accessing from a MachineOperand? I.e. how do I get to the MVT struct, or
equivalent information, from a MachineOperand object?

 

Micah Villmow

Systems Engineer

Advanced Technology & Performance

Advanced Micro Devices Inc.

4555 Great America Pkwy,

Santa Clara, CA. 95054

P: 408-572-6219

F: 408-572-6596

 

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To my knowledge, I don't think there is an easy way to get the MVT  
information from a MachineOperand.   Why do you need it for?  In my  
mind, the MachineInstr and its associated operands represent a  
physical machine instruction and I typically want to think of those as  
machine opcodes and machine register files.  I am typically interested  
in the mapping of MVTs to register classes when I'm generating machine  
instructions.  Note that a register class may map to multiple MVTs  
depending on your description.

-- Mon Ping

On Sep 24, 2008, at 12:15 PM, Villmow, Micah wrote:
> This only has the register class information, not the register type  
> information.
>
> My register class has multiple register types and I need to know how  
> to differentiate which register type of my register class of the  
> current register.
> The information in the MVT data type is what I need, i.e. the  
> position in the GPRVT array of each register.
>
> Something equivalent to MVT getValueType() but for registers.
>
> Thanks,
>
> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev- 
> bounces at cs.uiuc.edu] On Behalf Of Evan Cheng
> Sent: Wednesday, September 24, 2008 10:22 AM
> To: LLVM Developers Mailing List
> Subject: Re: [LLVMdev] Determining the register type of a  
> MachineOperand
>
> You can get to the MachineInstr from a MachineOperand. Then get to  
> its TargetInstrDesc and TargetOperandInfo which has register class  
> information.
>
> Evan
>
> On Sep 23, 2008, at 12:44 PM, Villmow, Micah wrote:
>
>
> How do I determine what type of register(i.e. i32, f32, etc..) I am  
> accessing from a MachineOperand? I.e. how do I get to the MVT  
> struct, or equivalent information, from a MachineOperand object?
>
> Micah Villmow
> Systems Engineer
> Advanced Technology & Performance
> Advanced Micro Devices Inc.
> 4555 Great America Pkwy,
> Santa Clara, CA. 95054
> P: 408-572-6219
> F: 408-572-6596
>
> _______________________________________________
> 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
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On Wednesday 24 September 2008 15:23, Mon Ping Wang
wrote:
> To my knowledge, I don't think there is an easy way to get the MVT
> information from a MachineOperand.   Why do you need it for?  In my
See the thread I started on this very topic.  Spilling is one place you'd
like
to have this information.
> mind, the MachineInstr and its associated operands represent a
> physical machine instruction and I typically want to think of those as
> machine opcodes and machine register files.  I am typically interested
> in the mapping of MVTs to register classes when I'm generating machine
> instructions.  Note that a register class may map to multiple MVTs
> depending on your description.
Right, but the instruction opcode should give a clue about what the bits 
represent.  That mapping is what's currently missing.

                                              -Dave