[PATCH] D20295: When looking for a spill slot in reg scavenger, find one that matches RC

[Matthias Braun via llvm-commits]

MatzeB added inline comments.

================
Comment at: llvm/trunk/lib/CodeGen/RegisterScavenging.cpp:445
@@ +444,3 @@
+      llvm_unreachable(Msg.str().c_str());
+      report_fatal_error(Msg);
+    }
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kparzysz wrote:
> I kept both.
This makes no sense. llvm_unreachable() is an indication that this case cannot happen and the compiler will actually optimize for this. There is a high chance it remove the report_fatal_error() in this case.
If you have an error that could actually be provoked by a user of the compiler (through inline assembly or similar) then report_fatal_error() is apropriate. If the problem can only be caused by a bug in llvm then llvm_unreachable() should be used.


Repository:
  rL LLVM

http://reviews.llvm.org/D20295