[LLVMdev] Machine Verifier question.

[Jakob Stoklund Olesen]

On May 9, 2010, at 5:27 AM, Lang Hames wrote:

> Running the following command,
> 
> llc -asm-verbose=false -O3 Output/ReedSolomon.llvm.bc -o Output/ReedSolomon.llc.s -verify-machineinstrs
> 
> in llvm-test/SingleSource/Benchmarks/Misc currently yields seven errors, all of the form
> 
> *** Bad machine code: PHI operand is not live-out from predecessor ***
> - function:    main
> - basic block: bb2.i.preheader 0x1ba7680 (BB#5)
> - instruction: %reg1032<def> = PHI %reg1280, <BB#3>, %reg1287, <BB#4>
> - operand 1:   %reg1280
> 
> The code seems to run ok though.
> 
> Is this something that's worth looking in to, or just over zealous reporting by the machine verifier?

That sounds like a proper bug. Can you tell why %reg1280 is not live-out from BB#3?

/jakob