llvm dev - Dec 2007 - [LLVMdev] strict aliasing warning in x86 land

/Volumes/mrs5/net/llvm/llvm/llvm/lib/Target/X86/X86ISelLowering.cpp:  
In member function 'llvm::SDOperand  
llvm::X86TargetLowering::LowerTRAMPOLINE(llvm::SDOperand,  
llvm::SelectionDAG&)':
/Volumes/mrs5/net/llvm/llvm/llvm/lib/Target/X86/X86ISelLowering.cpp: 
5305: warning: dereferencing type-punned pointer will break strict- 
aliasing rules

:-(

On Saturday 15 December 2007 08:36:02 Mike Stump wrote:
> /Volumes/mrs5/net/llvm/llvm/llvm/lib/Target/X86/X86ISelLowering.cpp:  
> In member function 'llvm::SDOperand  
> llvm::X86TargetLowering::LowerTRAMPOLINE(llvm::SDOperand,  
> llvm::SelectionDAG&)':
> /Volumes/mrs5/net/llvm/llvm/llvm/lib/Target/X86/X86ISelLowering.cpp: 
> 5305: warning: dereferencing type-punned pointer will break strict- 
> aliasing rules
> 
> :-(
Can you please paste the line (line number 5305 isn't in LowerTRAMPOLINE
in my tree...).

Thanks,

Duncan.

On Dec 15, 2007, at 2:15 AM, Duncan Sands wrote:
> Can you please paste the line (line number 5305 isn't in  
> LowerTRAMPOLINE
> in my tree...).
You have to run svn update for it to have that line...  :-)

     unsigned char N86Reg  =  
((X86RegisterInfo&)RegInfo).getX86RegNum(NestReg);

I've not thought long or hard about the validity of the warning...   
I'm hoping that it is accurate.  Let me know if you think otherwise.