[PATCH] D20156: PR24071 Fix an assert in SelectionDAGBuilder

[Diana Picus via llvm-commits]

rovka added inline comments.

================
Comment at: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:6793-6799
@@ -6792,7 +6792,9 @@
       if (OpInfo.AssignedRegs.Regs.empty()) {
         LLVMContext &Ctx = *DAG.getContext();
         Ctx.emitError(CS.getInstruction(),
                       "couldn't allocate output register for constraint '" +
                           Twine(OpInfo.ConstraintCode) + "'");
+        auto VT = TLI.getValueType(DAG.getDataLayout(), CS.getType());
+        setValue(CS.getInstruction(), DAG.getUNDEF(VT));
         return;
       }
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rnk wrote:
> Can you wrap up most of these calls into a helper like SelectionDAGBuilder::emitInlineAsmError(const Twine &) so that we don't forget to call setValue in the future?
Good idea. I'll post an updated version of this next week, after we get the new llc diagnostic handler (so I can add the tests too). Thanks.


http://reviews.llvm.org/D20156