Add DenseMap template and actually use it for for mapping virtual regs

to objects.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11840 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 203 insertions, 13 deletions

diff --git a/include/Support/DenseMap.h b/include/Support/DenseMap.h
new file mode 100644
index 0000000..5fcdfae
--- /dev/null
+++ b/include/Support/DenseMap.h
@@ -0,0 +1,61 @@
+//===- DenseMap.h - A dense map implmentation -------------------*- C++ -*-===//
+// 
+//                     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 file implements a dense map. A dense map template takes two
+// types. The first is the mapped type and the second is a functor
+// that maps its argument to a size_t. On instanciation a "null" value
+// can be provided to be used as a "does not exist" indicator in the
+// map. A member function grow() is provided that given the value of
+// the maximally indexed key (the argument of the functor) makes sure
+// the map has enough space for it.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_DENSEMAP_H
+#define SUPPORT_DENSEMAP_H
+
+#include <vector>
+
+namespace llvm {
+
+template <typename T, typename ToIndexT>
+class DenseMap {
+    typedef typename ToIndexT::argument_type IndexT;
+    typedef std::vector<T> StorageT;
+    StorageT storage_;
+    T nullVal_;
+    ToIndexT toIndex_;
+
+public:
+    DenseMap() { }
+
+    explicit DenseMap(const T& val) : nullVal_(val) { }
+
+    typename StorageT::reference operator[](IndexT n) {
+        assert(toIndex_(n) < storage_.size() && "index out of bounds!");
+        return storage_[toIndex_(n)];
+    }
+
+    typename StorageT::const_reference operator[](IndexT n) const {
+        assert(toIndex_(n) < storage_.size() && "index out of bounds!");
+        return storage_[toIndex_(n)];
+    }
+
+    void clear() {
+        storage_.assign(storage_.size(), nullVal_);
+    }
+
+    void grow(IndexT n) {
+        storage_.resize(toIndex_(n) + 1, nullVal_);
+    }
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/ADT/DenseMap.h b/include/llvm/ADT/DenseMap.h
new file mode 100644
index 0000000..5fcdfae
--- /dev/null
+++ b/include/llvm/ADT/DenseMap.h
@@ -0,0 +1,61 @@
+//===- DenseMap.h - A dense map implmentation -------------------*- C++ -*-===//
+// 
+//                     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 file implements a dense map. A dense map template takes two
+// types. The first is the mapped type and the second is a functor
+// that maps its argument to a size_t. On instanciation a "null" value
+// can be provided to be used as a "does not exist" indicator in the
+// map. A member function grow() is provided that given the value of
+// the maximally indexed key (the argument of the functor) makes sure
+// the map has enough space for it.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_DENSEMAP_H
+#define SUPPORT_DENSEMAP_H
+
+#include <vector>
+
+namespace llvm {
+
+template <typename T, typename ToIndexT>
+class DenseMap {
+    typedef typename ToIndexT::argument_type IndexT;
+    typedef std::vector<T> StorageT;
+    StorageT storage_;
+    T nullVal_;
+    ToIndexT toIndex_;
+
+public:
+    DenseMap() { }
+
+    explicit DenseMap(const T& val) : nullVal_(val) { }
+
+    typename StorageT::reference operator[](IndexT n) {
+        assert(toIndex_(n) < storage_.size() && "index out of bounds!");
+        return storage_[toIndex_(n)];
+    }
+
+    typename StorageT::const_reference operator[](IndexT n) const {
+        assert(toIndex_(n) < storage_.size() && "index out of bounds!");
+        return storage_[toIndex_(n)];
+    }
+
+    void clear() {
+        storage_.assign(storage_.size(), nullVal_);
+    }
+
+    void grow(IndexT n) {
+        storage_.resize(toIndex_(n) + 1, nullVal_);
+    }
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/ADT/IndexedMap.h b/include/llvm/ADT/IndexedMap.h
new file mode 100644
index 0000000..5fcdfae
--- /dev/null
+++ b/include/llvm/ADT/IndexedMap.h
@@ -0,0 +1,61 @@
+//===- DenseMap.h - A dense map implmentation -------------------*- C++ -*-===//
+// 
+//                     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 file implements a dense map. A dense map template takes two
+// types. The first is the mapped type and the second is a functor
+// that maps its argument to a size_t. On instanciation a "null" value
+// can be provided to be used as a "does not exist" indicator in the
+// map. A member function grow() is provided that given the value of
+// the maximally indexed key (the argument of the functor) makes sure
+// the map has enough space for it.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_DENSEMAP_H
+#define SUPPORT_DENSEMAP_H
+
+#include <vector>
+
+namespace llvm {
+
+template <typename T, typename ToIndexT>
+class DenseMap {
+    typedef typename ToIndexT::argument_type IndexT;
+    typedef std::vector<T> StorageT;
+    StorageT storage_;
+    T nullVal_;
+    ToIndexT toIndex_;
+
+public:
+    DenseMap() { }
+
+    explicit DenseMap(const T& val) : nullVal_(val) { }
+
+    typename StorageT::reference operator[](IndexT n) {
+        assert(toIndex_(n) < storage_.size() && "index out of bounds!");
+        return storage_[toIndex_(n)];
+    }
+
+    typename StorageT::const_reference operator[](IndexT n) const {
+        assert(toIndex_(n) < storage_.size() && "index out of bounds!");
+        return storage_[toIndex_(n)];
+    }
+
+    void clear() {
+        storage_.assign(storage_.size(), nullVal_);
+    }
+
+    void grow(IndexT n) {
+        storage_.resize(toIndex_(n) + 1, nullVal_);
+    }
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/CodeGen/SSARegMap.h b/include/llvm/CodeGen/SSARegMap.h
index 65c0cce..afed38a 100644
--- a/include/llvm/CodeGen/SSARegMap.h
+++ b/include/llvm/CodeGen/SSARegMap.h
@@ -18,35 +18,34 @@
 #define LLVM_CODEGEN_SSAREGMAP_H
 
 #include "llvm/Target/MRegisterInfo.h"
+#include "Support/DenseMap.h"
 
 namespace llvm {
 
 class TargetRegisterClass;
 
 class SSARegMap {
-  std::vector<const TargetRegisterClass*> RegClassMap;
-
-  unsigned rescale(unsigned Reg) {
-    return Reg - MRegisterInfo::FirstVirtualRegister;
-  }
+  DenseMap<const TargetRegisterClass*, VirtReg2IndexFunctor> RegClassMap;
+  unsigned NextRegNum;
 
  public:
+  SSARegMap() : NextRegNum(MRegisterInfo::FirstVirtualRegister) { }
+
   const TargetRegisterClass* getRegClass(unsigned Reg) {
-    unsigned actualReg = rescale(Reg);
-    assert(actualReg < RegClassMap.size() && "Register out of bounds");
-    return RegClassMap[actualReg];
+    return RegClassMap[Reg];
   }
 
   /// createVirtualRegister - Create and return a new virtual register in the
   /// function with the specified register class.
   ///
   unsigned createVirtualRegister(const TargetRegisterClass *RegClass) {
-    RegClassMap.push_back(RegClass);
-    return RegClassMap.size()+MRegisterInfo::FirstVirtualRegister-1;
+    RegClassMap.grow(NextRegNum);
+    RegClassMap[NextRegNum] = RegClass;
+    return NextRegNum++;
   }
 
-  unsigned getNumVirtualRegs() const {
-    return RegClassMap.size();
+  unsigned getLastVirtReg() const {
+    return NextRegNum - 1;
   }
 };
 
diff --git a/include/llvm/Target/MRegisterInfo.h b/include/llvm/Target/MRegisterInfo.h
index ce39f09..0a83ac2 100644
--- a/include/llvm/Target/MRegisterInfo.h
+++ b/include/llvm/Target/MRegisterInfo.h
@@ -16,8 +16,9 @@
 #ifndef LLVM_TARGET_MREGISTERINFO_H
 #define LLVM_TARGET_MREGISTERINFO_H
 
-#include <cassert>
 #include "llvm/CodeGen/MachineBasicBlock.h"
+#include <cassert>
+#include <functional>
 
 namespace llvm {
 
@@ -319,6 +320,13 @@ public:
                             MachineBasicBlock &MBB) const = 0;
 };
 
+// This is useful when building DenseMap's keyed on virtual registers
+struct VirtReg2IndexFunctor : std::unary_function<unsigned, unsigned> {
+  unsigned operator()(unsigned Reg) const {
+    return Reg - MRegisterInfo::FirstVirtualRegister;
+  }
+};
+
 } // End llvm namespace
 
 #endif