NVPTX: Use MapMetadata() instead of custom/stale/untested logic

Copy the `GVMap` over to a standard `ValueToValueMapTy` so that we can
reuse the `MapMetadata()` logic.  Unfortunately the `GVMap` can't just
be replaced, since `MapMetadata()` likes to modify the map, but at least
this will prevent NVPTX from bitrotting.

llvm-svn: 225944

1 files changed, 10 insertions, 41 deletions

diff --git a/llvm/lib/Target/NVPTX/NVPTXGenericToNVVM.cpp b/llvm/lib/Target/NVPTX/NVPTXGenericToNVVM.cpp
index c37eaff..5f06d9a 100644
--- a/llvm/lib/Target/NVPTX/NVPTXGenericToNVVM.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXGenericToNVVM.cpp
@@ -26,6 +26,7 @@
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/ValueMap.h"
 #include "llvm/PassManager.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
 
 using namespace llvm;
 
@@ -54,8 +55,7 @@ private:
                                                 IRBuilder<> &Builder);
   Value *remapConstantExpr(Module *M, Function *F, ConstantExpr *C,
                            IRBuilder<> &Builder);
-  void remapNamedMDNode(Module *M, NamedMDNode *N);
-  MDNode *remapMDNode(Module *M, MDNode *N);
+  void remapNamedMDNode(ValueToValueMapTy &VM, NamedMDNode *N);
 
   typedef ValueMap<GlobalVariable *, GlobalVariable *> GVMapTy;
   typedef ValueMap<Constant *, Value *> ConstantToValueMapTy;
@@ -125,12 +125,17 @@ bool GenericToNVVM::runOnModule(Module &M) {
     ConstantToValueMap.clear();
   }
 
+  // Copy GVMap over to a standard value map.
+  ValueToValueMapTy VM;
+  for (auto I = GVMap.begin(), E = GVMap.end(); I != E; ++I)
+    VM[I->first] = I->second;
+
   // Walk through the metadata section and update the debug information
   // associated with the global variables in the default address space.
   for (Module::named_metadata_iterator I = M.named_metadata_begin(),
                                        E = M.named_metadata_end();
        I != E; I++) {
-    remapNamedMDNode(&M, I);
+    remapNamedMDNode(VM, I);
   }
 
   // Walk through the global variable  initializers, and replace any use of
@@ -362,7 +367,7 @@ Value *GenericToNVVM::remapConstantExpr(Module *M, Function *F, ConstantExpr *C,
   }
 }
 
-void GenericToNVVM::remapNamedMDNode(Module *M, NamedMDNode *N) {
+void GenericToNVVM::remapNamedMDNode(ValueToValueMapTy &VM, NamedMDNode *N) {
 
   bool OperandChanged = false;
   SmallVector<MDNode *, 16> NewOperands;
@@ -372,7 +377,7 @@ void GenericToNVVM::remapNamedMDNode(Module *M, NamedMDNode *N) {
   // converted to another value.
   for (unsigned i = 0; i < NumOperands; ++i) {
     MDNode *Operand = N->getOperand(i);
-    MDNode *NewOperand = remapMDNode(M, Operand);
+    MDNode *NewOperand = MapMetadata(Operand, VM);
     OperandChanged |= Operand != NewOperand;
     NewOperands.push_back(NewOperand);
   }
@@ -390,39 +395,3 @@ void GenericToNVVM::remapNamedMDNode(Module *M, NamedMDNode *N) {
     N->addOperand(*I);
   }
 }
-
-MDNode *GenericToNVVM::remapMDNode(Module *M, MDNode *N) {
-
-  bool OperandChanged = false;
-  SmallVector<Metadata *, 8> NewOperands;
-  unsigned NumOperands = N->getNumOperands();
-
-  // Check if any operand is or contains a global variable in  GVMap, and thus
-  // converted to another value.
-  for (unsigned i = 0; i < NumOperands; ++i) {
-    Metadata *Operand = N->getOperand(i);
-    Metadata *NewOperand = Operand;
-    if (Operand) {
-      if (auto *N = dyn_cast<MDNode>(Operand)) {
-        NewOperand = remapMDNode(M, N);
-      } else if (auto *C = dyn_cast<ConstantAsMetadata>(Operand)) {
-        if (auto *G = dyn_cast<GlobalVariable>(C->getValue())) {
-          GVMapTy::iterator I = GVMap.find(G);
-          if (I != GVMap.end())
-            NewOperand = ConstantAsMetadata::get(I->second);
-        }
-      }
-    }
-    OperandChanged |= Operand != NewOperand;
-    NewOperands.push_back(NewOperand);
-  }
-
-  // If none of the operands has been modified, return N as it is.
-  if (!OperandChanged) {
-    return N;
-  }
-
-  // If any of the operands has been modified, create a new MDNode with the new
-  // operands.
-  return MDNode::get(M->getContext(), makeArrayRef(NewOperands));
-}