* Remove dead code from ExprTypeConvert.cpp

   - I->use_empty() can never be true because of the IHolder's
* Fix bug: test/Regression/Transforms/LevelRaise/2002-07-16-SourceAndDestCrash.ll
   - Add a new NewCasts member to VMC to keep track of casts that have been
     created and to ensure there is always a reference to the cast.
   - Extend ValueHandle a bit so it can be used in an STL container
   - Make sure we destroy the ValueMapCache before verifying the function
     in LevelRaise.cpp

llvm-svn: 2936

1 files changed, 15 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/LevelRaise.cpp b/llvm/lib/Transforms/LevelRaise.cpp
index 94aebcbc658..7e27c5f7f0b 100644
--- a/llvm/lib/Transforms/LevelRaise.cpp
+++ b/llvm/lib/Transforms/LevelRaise.cpp
@@ -225,17 +225,20 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
         PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", Src, CI, BB->getParent());
           
         DEBUG(cerr << "\nCONVERTING SRC EXPR TYPE:\n");
-        ValueMapCache ValueMap;
-        Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
-        if (Constant *CPV = dyn_cast<Constant>(E))
-          CI->replaceAllUsesWith(CPV);
+        { // ValueMap must be destroyed before function verified!
+          ValueMapCache ValueMap;
+          Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
 
-        BI = BB->begin();  // Rescan basic block.  BI might be invalidated.
-        PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
-        DEBUG(cerr << "DONE CONVERTING SRC EXPR TYPE: \n" << BB->getParent());
+          if (Constant *CPV = dyn_cast<Constant>(E))
+            CI->replaceAllUsesWith(CPV);
+          
+          PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
+          DEBUG(cerr << "DONE CONVERTING SRC EXPR TYPE: \n" << BB->getParent());
+        }
 
         DEBUG(assert(verifyFunction(*BB->getParent()) == false &&
                      "Function broken!"));
+        BI = BB->begin();  // Rescan basic block.  BI might be invalidated.
         ++NumExprTreesConv;
         return true;
       }
@@ -249,15 +252,17 @@ static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
         PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", Src, CI, BB->getParent());
 
         DEBUG(cerr << "\nCONVERTING EXPR TYPE:\n");
-        ValueMapCache ValueMap;
-        ConvertValueToNewType(CI, Src, ValueMap);  // This will delete CI!
+        { // ValueMap must be destroyed before function verified!
+          ValueMapCache ValueMap;
+          ConvertValueToNewType(CI, Src, ValueMap);  // This will delete CI!
+        }
 
-        BI = BB->begin();  // Rescan basic block.  BI might be invalidated.
         PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src);
         DEBUG(cerr << "DONE CONVERTING EXPR TYPE: \n\n" << BB->getParent());
 
         DEBUG(assert(verifyFunction(*BB->getParent()) == false &&
                      "Function broken!"));
+        BI = BB->begin();  // Rescan basic block.  BI might be invalidated.
         ++NumExprTreesConv;
         return true;
       }