clarify some comments, simplify some checks, fix:
Regression/Transforms/IndVarsSimplify/2006-12-10-BitCast.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32420 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 9fc0c76..710983b 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1371,24 +1371,24 @@
       break;
 
     case Instruction::Trunc:
-      // We must prevent boolean types such as setne, etc. from entering here
-      // because we don't want to pass SCEVUnknown to the TruncateExpr.
-      if (I->getType()->isInteger() && I->getOperand(0)->getType()->isInteger())
+      // We don't handle trunc to bool yet.
+      if (I->getType()->isInteger())
         return SCEVTruncateExpr::get(getSCEV(I->getOperand(0)), 
                                      I->getType()->getUnsignedVersion());
       break;
 
     case Instruction::ZExt:
-      // We must prevent boolean types such as setne, etc. from entering here
-      // because we don't want to pass SCEVUnknown to the ZExtExpr.
-      if (I->getType()->isInteger() && I->getOperand(0)->getType()->isInteger())
+      // We don't handle zext from bool yet.
+      if (I->getOperand(0)->getType()->isInteger())
         return SCEVZeroExtendExpr::get(getSCEV(I->getOperand(0)), 
                                        I->getType()->getUnsignedVersion());
       break;
 
     case Instruction::BitCast:
       // BitCasts are no-op casts so we just eliminate the cast.
-      return getSCEV(I->getOperand(0));
+      if (I->getType()->isInteger() && I->getOperand(0)->getType()->isInteger())
+        return getSCEV(I->getOperand(0));
+      break;
 
     case Instruction::PHI:
       return createNodeForPHI(cast<PHINode>(I));