[Utils] salvageDI: Add a comment and move a call earlier, NFC

llvm-svn: 325280

1 files changed, 3 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 39d66e0f9b0..e75127f77e8 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1492,6 +1492,7 @@ void llvm::salvageDebugInfo(Instruction &I) {
     return;
 
   auto &M = *I.getModule();
+  auto &DL = M.getDataLayout();
 
   auto wrapMD = [&](Value *V) {
     return MetadataAsValue::get(I.getContext(), ValueAsMetadata::get(V));
@@ -1519,7 +1520,7 @@ void llvm::salvageDebugInfo(Instruction &I) {
   };
 
   if (auto *CI = dyn_cast<CastInst>(&I)) {
-    if (!CI->isNoopCast(M.getDataLayout()))
+    if (!CI->isNoopCast(DL))
       return;
 
     // No-op casts are irrelevant for debug info.
@@ -1539,6 +1540,7 @@ void llvm::salvageDebugInfo(Instruction &I) {
       for (auto *DII : DbgUsers)
         applyOffset(DII, Offset.getSExtValue());
   } else if (auto *BI = dyn_cast<BinaryOperator>(&I)) {
+    // Rewrite binary operations with constant integer operands.
     auto *ConstInt = dyn_cast<ConstantInt>(I.getOperand(1));
     if (!ConstInt || ConstInt->getBitWidth() > 64)
       return;