DataLayout is mandatory, update the API to reflect it with references.

[oota-llvm.git] / include / llvm / Analysis / ConstantFolding.h

diff --git a/include/llvm/Analysis/ConstantFolding.h b/include/llvm/Analysis/ConstantFolding.h
index ef1c052d9eee62124948264c2e09ec1cf7520cc0..541a2109af6cde4a5ddd83422e34c51a29fd49b0 100644 (file)
--- a/include/llvm/Analysis/ConstantFolding.h
+++ b/include/llvm/Analysis/ConstantFolding.h
@@ -1,30 +1,102 @@
-//===-- ConstantFolding.h - Analyze constant folding possibilities --------===//
+//===-- ConstantFolding.h - Fold instructions into constants ----*- 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 is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
-// This family of functions determines the possibility of performing constant
-// folding.
+// This file declares routines for folding instructions into constants when all
+// operands are constants, for example "sub i32 1, 0" -> "1".
+//
+// Also, to supplement the basic VMCore ConstantExpr simplifications,
+// this file declares some additional folding routines that can make use of
+// DataLayout information. These functions cannot go in VMCore due to library
+// dependency issues.
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Constants.h"
-#include "llvm/Function.h"
-using namespace llvm;
+#ifndef LLVM_ANALYSIS_CONSTANTFOLDING_H
+#define LLVM_ANALYSIS_CONSTANTFOLDING_H
 
 namespace llvm {
+  class Constant;
+  class ConstantExpr;
+  class Instruction;
+  class DataLayout;
+  class TargetLibraryInfo;
+  class Function;
+  class Type;
+  template<typename T>
+  class ArrayRef;
+
+/// ConstantFoldInstruction - Try to constant fold the specified instruction.
+/// If successful, the constant result is returned, if not, null is returned.
+/// Note that this fails if not all of the operands are constant.  Otherwise,
+/// this function can only fail when attempting to fold instructions like loads
+/// and stores, which have no constant expression form.
+  Constant *ConstantFoldInstruction(Instruction *I, const DataLayout &DL,
+                                    const TargetLibraryInfo *TLI = nullptr);
+
+/// ConstantFoldConstantExpression - Attempt to fold the constant expression
+/// using the specified DataLayout.  If successful, the constant result is
+/// result is returned, if not, null is returned.
+  Constant *
+  ConstantFoldConstantExpression(const ConstantExpr *CE, const DataLayout &DL,
+                                 const TargetLibraryInfo *TLI = nullptr);
+
+/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
+/// specified operands.  If successful, the constant result is returned, if not,
+/// null is returned.  Note that this function can fail when attempting to
+/// fold instructions like loads and stores, which have no constant expression
+/// form.
+///
+  Constant *ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
+                                     ArrayRef<Constant *> Ops,
+                                     const DataLayout &DL,
+                                     const TargetLibraryInfo *TLI = nullptr);
+
+/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare
+/// instruction (icmp/fcmp) with the specified operands.  If it fails, it
+/// returns a constant expression of the specified operands.
+///
+  Constant *
+  ConstantFoldCompareInstOperands(unsigned Predicate, Constant *LHS,
+                                  Constant *RHS, const DataLayout &DL,
+                                  const TargetLibraryInfo *TLI = nullptr);
+
+/// ConstantFoldInsertValueInstruction - Attempt to constant fold an insertvalue
+/// instruction with the specified operands and indices.  The constant result is
+/// returned if successful; if not, null is returned.
+Constant *ConstantFoldInsertValueInstruction(Constant *Agg, Constant *Val,
+                                             ArrayRef<unsigned> Idxs);
+
+/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would
+/// produce if it is constant and determinable.  If this is not determinable,
+/// return null.
+Constant *ConstantFoldLoadFromConstPtr(Constant *C, const DataLayout &DL);
+
+/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
+/// getelementptr constantexpr, return the constant value being addressed by the
+/// constant expression, or null if something is funny and we can't decide.
+Constant *ConstantFoldLoadThroughGEPConstantExpr(Constant *C, ConstantExpr *CE);
+
+/// ConstantFoldLoadThroughGEPIndices - Given a constant and getelementptr
+/// indices (with an *implied* zero pointer index that is not in the list),
+/// return the constant value being addressed by a virtual load, or null if
+/// something is funny and we can't decide.
+Constant *ConstantFoldLoadThroughGEPIndices(Constant *C,
+                                            ArrayRef<Constant*> Indices);
 
 /// canConstantFoldCallTo - Return true if its even possible to fold a call to
 /// the specified function.
-bool canConstantFoldCallTo(Function *F);
+bool canConstantFoldCallTo(const Function *F);
 
 /// ConstantFoldCall - Attempt to constant fold a call to the specified function
 /// with the specified arguments, returning null if unsuccessful.
-Constant *
-ConstantFoldCall(Function *F, Constant** Operands, unsigned NumOperands);
+Constant *ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
+                           const TargetLibraryInfo *TLI = nullptr);
 }
 
+#endif