It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
new file mode 100644
index 0000000..0b8c5c2
--- /dev/null
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -0,0 +1,118 @@
+//===- ValueMapper.cpp - Interface shared by lib/Transforms/Utils ---------===//
+//
+//                     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 defines the MapValue function, which is shared by various parts of
+// the lib/Transforms/Utils library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ValueMapper.h"
+#include "llvm/Constants.h"
+#include "llvm/GlobalValue.h"
+#include "llvm/Instruction.h"
+using namespace llvm;
+
+Value *llvm::MapValue(const Value *V, ValueMapTy &VM) {
+  Value *&VMSlot = VM[V];
+  if (VMSlot) return VMSlot;      // Does it exist in the map yet?
+  
+  // NOTE: VMSlot can be invalidated by any reference to VM, which can grow the
+  // DenseMap.  This includes any recursive calls to MapValue.
+
+  // Global values do not need to be seeded into the ValueMap if they are using
+  // the identity mapping.
+  if (isa<GlobalValue>(V) || isa<InlineAsm>(V))
+    return VMSlot = const_cast<Value*>(V);
+
+  if (Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V))) {
+    if (isa<ConstantInt>(C) || isa<ConstantFP>(C) ||
+        isa<ConstantPointerNull>(C) || isa<ConstantAggregateZero>(C) ||
+        isa<UndefValue>(C))
+      return VMSlot = C;           // Primitive constants map directly
+    else if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
+      for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
+        Value *MV = MapValue(CA->getOperand(i), VM);
+        if (MV != CA->getOperand(i)) {
+          // This array must contain a reference to a global, make a new array
+          // and return it.
+          //
+          std::vector<Constant*> Values;
+          Values.reserve(CA->getNumOperands());
+          for (unsigned j = 0; j != i; ++j)
+            Values.push_back(CA->getOperand(j));
+          Values.push_back(cast<Constant>(MV));
+          for (++i; i != e; ++i)
+            Values.push_back(cast<Constant>(MapValue(CA->getOperand(i), VM)));
+          return VM[V] = ConstantArray::get(CA->getType(), Values);
+        }
+      }
+      return VM[V] = C;
+
+    } else if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
+      for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
+        Value *MV = MapValue(CS->getOperand(i), VM);
+        if (MV != CS->getOperand(i)) {
+          // This struct must contain a reference to a global, make a new struct
+          // and return it.
+          //
+          std::vector<Constant*> Values;
+          Values.reserve(CS->getNumOperands());
+          for (unsigned j = 0; j != i; ++j)
+            Values.push_back(CS->getOperand(j));
+          Values.push_back(cast<Constant>(MV));
+          for (++i; i != e; ++i)
+            Values.push_back(cast<Constant>(MapValue(CS->getOperand(i), VM)));
+          return VM[V] = ConstantStruct::get(CS->getType(), Values);
+        }
+      }
+      return VM[V] = C;
+
+    } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+      std::vector<Constant*> Ops;
+      for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
+        Ops.push_back(cast<Constant>(MapValue(CE->getOperand(i), VM)));
+      return VM[V] = CE->getWithOperands(Ops);
+    } else if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) {
+      for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i) {
+        Value *MV = MapValue(CP->getOperand(i), VM);
+        if (MV != CP->getOperand(i)) {
+          // This vector value must contain a reference to a global, make a new
+          // vector constant and return it.
+          //
+          std::vector<Constant*> Values;
+          Values.reserve(CP->getNumOperands());
+          for (unsigned j = 0; j != i; ++j)
+            Values.push_back(CP->getOperand(j));
+          Values.push_back(cast<Constant>(MV));
+          for (++i; i != e; ++i)
+            Values.push_back(cast<Constant>(MapValue(CP->getOperand(i), VM)));
+          return VM[V] = ConstantVector::get(Values);
+        }
+      }
+      return VM[V] = C;
+      
+    } else {
+      assert(0 && "Unknown type of constant!");
+    }
+  }
+
+  return 0;
+}
+
+/// RemapInstruction - Convert the instruction operands from referencing the
+/// current values into those specified by ValueMap.
+///
+void llvm::RemapInstruction(Instruction *I, ValueMapTy &ValueMap) {
+  for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
+    const Value *Op = I->getOperand(op);
+    Value *V = MapValue(Op, ValueMap);
+    assert(V && "Referenced value not in value map!");
+    I->setOperand(op, V);
+  }
+}