Don't delete volatile loads. Doing so is not safe.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40448 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/Transforms/Scalar/FastDLE.cpp b/lib/Transforms/Scalar/FastDLE.cpp
index 001f834b5f..74712ad83f 100644
--- a/lib/Transforms/Scalar/FastDLE.cpp
+++ b/lib/Transforms/Scalar/FastDLE.cpp
@@ -69,6 +69,12 @@ bool FDLE::runOnBasicBlock(BasicBlock &BB) {
   for (BasicBlock::iterator BBI = BB.begin(), BBE = BB.end(); BBI != BBE; ++BBI) {
     // If we find a store or a free...
     if (LoadInst* L = dyn_cast<LoadInst>(BBI)) {
+      // We can't delete volatile loads
+      if (L->isVolatile()) {
+        lastLoad[L->getPointerOperand()] = L;
+        continue;
+      }
+      
       Value* pointer = L->getPointerOperand();
       LoadInst*& last = lastLoad[pointer];