Allow custom lowered FP_TO_SINT ops in the check for whether a larger

[oota-llvm.git] / lib / CodeGen / UnreachableBlockElim.cpp

diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp
index bcc124538d31c37b0ebc7d782158650ece079f55..1d4e5304f3b08313d6488fb571b24b7835a9a001 100644 (file)
--- a/lib/CodeGen/UnreachableBlockElim.cpp
+++ b/lib/CodeGen/UnreachableBlockElim.cpp
@@ -1,12 +1,12 @@
 //===-- UnreachableBlockElim.cpp - Remove unreachable blocks for codegen --===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by the LLVM research group and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+//
 //===----------------------------------------------------------------------===//
-// 
+//
 // This pass is an extremely simple version of the SimplifyCFG pass.  Its sole
 // job is to delete LLVM basic blocks that are not reachable from the entry
 // node.  To do this, it performs a simple depth first traversal of the CFG,
@@ -21,10 +21,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/Passes.h"
+#include "llvm/Constant.h"
+#include "llvm/Instructions.h"
 #include "llvm/Function.h"
 #include "llvm/Pass.h"
+#include "llvm/Type.h"
 #include "llvm/Support/CFG.h"
-#include "Support/DepthFirstIterator.h"
+#include "llvm/ADT/DepthFirstIterator.h"
 using namespace llvm;
 
 namespace {
@@ -52,10 +55,15 @@ bool UnreachableBlockElim::runOnFunction(Function &F) {
   std::vector<BasicBlock*> DeadBlocks;
   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
     if (!Reachable.count(I)) {
-      DeadBlocks.push_back(I);
-      for (succ_iterator SI = succ_begin(&*I), E = succ_end(&*I); SI != E; ++SI)
-        (*SI)->removePredecessor(I);
-      I->dropAllReferences();
+      BasicBlock *BB = I;
+      DeadBlocks.push_back(BB);
+      while (PHINode *PN = dyn_cast<PHINode>(BB->begin())) {
+        PN->replaceAllUsesWith(Constant::getNullValue(PN->getType()));
+        BB->getInstList().pop_front();
+      }
+      for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI)
+        (*SI)->removePredecessor(BB);
+      BB->dropAllReferences();
     }
 
   if (DeadBlocks.empty()) return false;