Implement new LibCallSimplifier class

This patch implements the new LibCallSimplifier class as outlined in [1].
In addition to providing the new base library simplification infrastructure,
all the fortified library call simplifications were moved over to the new
infrastructure.  The rest of the library simplification optimizations will
be moved over with follow up patches.

NOTE: The original fortified library call simplifier located in the
SimplifyFortifiedLibCalls class was not removed because it is still
used by CodeGenPrepare.  This class will eventually go away too.

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-August/052283.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165873 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 43 insertions, 0 deletions

diff --git a/include/llvm/Transforms/Utils/SimplifyLibCalls.h b/include/llvm/Transforms/Utils/SimplifyLibCalls.h
new file mode 100644
index 0000000000..5db2d00181
--- /dev/null
+++ b/include/llvm/Transforms/Utils/SimplifyLibCalls.h
@@ -0,0 +1,43 @@
+//===- SimplifyLibCalls.h - Library call simplifier -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file exposes an interface to build some C language libcalls for
+// optimization passes that need to call the various functions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_UTILS_SIMPLIFYLIBCALLS_H
+#define LLVM_TRANSFORMS_UTILS_SIMPLIFYLIBCALLS_H
+
+namespace llvm {
+  class Value;
+  class CallInst;
+  class DataLayout;
+  class TargetLibraryInfo;
+  class LibCallSimplifierImpl;
+
+  /// LibCallSimplifier - This class implements a collection of optimizations
+  /// that replace well formed calls to library functions with a more optimal
+  /// form.  For example, replacing 'printf("Hello!")' with 'puts("Hello!")'.
+  class LibCallSimplifier {
+    /// Impl - A pointer to the actual implementation of the library call
+    /// simplifier.
+    LibCallSimplifierImpl *Impl;
+  public:
+    LibCallSimplifier(const DataLayout *TD, const TargetLibraryInfo *TLI);
+    virtual ~LibCallSimplifier();
+
+    /// optimizeCall - Take the given call instruction and return a more
+    /// optimal value to replace the instruction with or 0 if a more
+    /// optimal form can't be found.
+    Value *optimizeCall(CallInst *CI);
+  };
+} // End llvm namespace
+
+#endif