Allow the specification of explicit alignments for constant pool entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25855 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 24 insertions, 11 deletions

diff --git a/include/llvm/CodeGen/MachineConstantPool.h b/include/llvm/CodeGen/MachineConstantPool.h
index c2c3399adb..1bbf88d843 100644
--- a/include/llvm/CodeGen/MachineConstantPool.h
+++ b/include/llvm/CodeGen/MachineConstantPool.h
@@ -30,20 +30,23 @@ namespace llvm {
 class Constant;
 
 class MachineConstantPool {
-  std::vector<Constant*> Constants;
+  std::vector<std::pair<Constant*,unsigned> > Constants;
 public:
 
   /// getConstantPoolIndex - Create a new entry in the constant pool or return
-  /// an existing one.
+  /// an existing one. User may specify an alignment that is greater than the
+  /// default alignment. If one is not specified, it will be 0.
   ///
-  unsigned getConstantPoolIndex(Constant *C) {
+  unsigned getConstantPoolIndex(Constant *C, unsigned Alignment = 0) {
     // Check to see if we already have this constant.
     //
     // FIXME, this could be made much more efficient for large constant pools.
     for (unsigned i = 0, e = Constants.size(); i != e; ++i)
-      if (Constants[i] == C)
+      if (Constants[i].first == C) {
+        Constants[i].second = std::max(Constants[i].second, Alignment);
         return i;
-    Constants.push_back(C);
+      }
+    Constants.push_back(std::make_pair(C, Alignment));
     return Constants.size()-1;
   }
 
@@ -51,7 +54,9 @@ public:
   ///
   bool isEmpty() const { return Constants.empty(); }
 
-  const std::vector<Constant*> &getConstants() const { return Constants; }
+  const std::vector<std::pair<Constant*,unsigned> > &getConstants() const {
+    return Constants;
+  }
 
   /// print - Used by the MachineFunction printer to print information about
   /// stack objects.  Implemented in MachineFunction.cpp
diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 195e8e435b..6d75e47acf 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -120,8 +120,10 @@ public:
                                    int offset = 0);
   SDOperand getFrameIndex(int FI, MVT::ValueType VT);
   SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT);
-  SDOperand getConstantPool(Constant *C, MVT::ValueType VT);
-  SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT);
+  SDOperand getConstantPool(Constant *C, MVT::ValueType VT,
+                            unsigned Alignment=0);
+  SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT,
+                                  unsigned Alignment=0);
   SDOperand getBasicBlock(MachineBasicBlock *MBB);
   SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
   SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
@@ -606,8 +608,8 @@ private:
   std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
   std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstantFPs;
   std::map<int, SDNode*> FrameIndices, TargetFrameIndices;
-  std::map<Constant *, SDNode*> ConstantPoolIndices;
-  std::map<Constant *, SDNode*> TargetConstantPoolIndices;
+  std::map<std::pair<Constant *, unsigned>, SDNode*> ConstantPoolIndices;
+  std::map<std::pair<Constant *, unsigned>, SDNode*> TargetConstantPoolIndices;
   std::map<MachineBasicBlock *, SDNode*> BBNodes;
   std::vector<SDNode*> ValueTypeNodes;
   std::map<std::string, SDNode*> ExternalSymbols;
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index ae2519a836..0b850e617b 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1058,14 +1058,20 @@ public:
 
 class ConstantPoolSDNode : public SDNode {
   Constant *C;
+  unsigned Alignment;
 protected:
   friend class SelectionDAG;
   ConstantPoolSDNode(Constant *c, MVT::ValueType VT, bool isTarget)
     : SDNode(isTarget ? ISD::TargetConstantPool : ISD::ConstantPool, VT),
-    C(c) {}
+    C(c), Alignment(0) {}
+  ConstantPoolSDNode(Constant *c, MVT::ValueType VT, unsigned Align,
+                     bool isTarget)
+    : SDNode(isTarget ? ISD::TargetConstantPool : ISD::ConstantPool, VT),
+    C(c), Alignment(Align) {}
 public:
 
   Constant *get() const { return C; }
+  unsigned getAlignment() const { return Alignment; }
 
   static bool classof(const ConstantPoolSDNode *) { return true; }
   static bool classof(const SDNode *N) {