[llvm] r242264 - Use cast<> instead of dyn_cast to remove llvm_unreachable. NFC.

[Pete Cooper]

Author: pete
Date: Tue Jul 14 20:31:23 2015
New Revision: 242264

URL: http://llvm.org/viewvc/llvm-project?rev=242264&view=rev
Log:
Use cast<> instead of dyn_cast to remove llvm_unreachable.  NFC.

This code was checking if we are an ICmpInst or FCmpInst then throwing
unreachable if we are neither.  We must be one or the other, so use a
cast on the FCmpInst case to ensure that we are that case.  Then we can
avoid having an unreachable but still catch an error if we ever had another
subclass of CmpInst.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=242264&r1=242263&r2=242264&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Tue Jul 14 20:31:23 2015
@@ -1375,13 +1375,11 @@ SelectionDAGBuilder::EmitBranchForMerged
       ISD::CondCode Condition;
       if (const ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) {
         Condition = getICmpCondCode(IC->getPredicate());
-      } else if (const FCmpInst *FC = dyn_cast<FCmpInst>(Cond)) {
+      } else {
+        const FCmpInst *FC = cast<FCmpInst>(Cond);
         Condition = getFCmpCondCode(FC->getPredicate());
         if (TM.Options.NoNaNsFPMath)
           Condition = getFCmpCodeWithoutNaN(Condition);
-      } else {
-        (void)Condition; // silence warning.
-        llvm_unreachable("Unknown compare instruction");
       }
 
       CaseBlock CB(Condition, BOp->getOperand(0), BOp->getOperand(1), nullptr,