[PATCH] D105953: [MachineVerifier] Diagnose invalid INSERT_SUBREGs

[Jon Roelofs via Phabricator via llvm-commits]

jroelofs added inline comments.


================
Comment at: llvm/lib/CodeGen/MachineVerifier.cpp:1787
+    unsigned InsertedSize =
+        TRI->getRegSizeInBits(MI->getOperand(2).getReg(), *MRI);
+    unsigned SubRegSize = TRI->getSubRegIdxSize(MI->getOperand(3).getImm());
----------------
uabelho wrote:
> uabelho wrote:
> > Don't you need to take operand 2's subreg into account here?
> > 
> > I'm seeing failures for cases where
> > ```
> >  MI->getOperand(2).getReg()
> > ```
> > is indeed too big, but
> > ```
> > MI->getOperand(2).getSubReg()
> > ```
> > is specifying a subreg of a small enough size so there is no problem.
> This seems to work better for me:
> ```
>     unsigned InsertedSize;
>     if (unsigned SubIdx = MI->getOperand(2).getSubReg())
>       InsertedSize = TRI->getSubRegIdxSize(SubIdx);
>     else
>       InsertedSize =
>         TRI->getRegSizeInBits(MI->getOperand(2).getReg(), *MRI);
> ```
Good call, thanks!

4de74a7c4da3516d0d9119452cc073b061716b5d


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https://reviews.llvm.org/D105953