-//===-- ConstantFolding.h - Analyze constant folding possibilities --------===//
+//===-- ConstantFolding.h - Fold instructions into constants --------------===//
//
// 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.
+//
+// Also, to supplement the basic VMCore ConstantExpr simplifications,
+// this file declares some additional folding routines that can make use of
+// TargetData 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 TargetData;
+ class Function;
+ class Type;
+
+/// ConstantFoldInstruction - Attempt to constant fold the specified
+/// instruction. If successful, the constant result is returned, if not, null
+/// is returned. Note that 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 TargetData *TD = 0);
+
+/// ConstantFoldConstantExpression - Attempt to fold the constant expression
+/// using the specified TargetData. If successful, the constant result is
+/// result is returned, if not, null is returned.
+Constant *ConstantFoldConstantExpression(ConstantExpr *CE,
+ const TargetData *TD = 0);
+
+/// 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, const Type *DestTy,
+ Constant *const *Ops, unsigned NumOps,
+ const TargetData *TD = 0);
+
+/// 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 TargetData *TD = 0);
+
+/// 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 TargetData *TD = 0);
+/// 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);
+
/// 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);
+ConstantFoldCall(Function *F, Constant *const *Operands, unsigned NumOperands);
}
+#endif