-//===-- InstructionSimplify.h - Fold instructions into simpler forms ------===//
+//===-- InstructionSimplify.h - Fold instrs into simpler forms --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
//
-// This file declares routines for folding instructions into simpler forms that
-// do not require creating new instructions. For example, this does constant
-// folding, and can handle identities like (X&0)->0.
+// This file declares routines for folding instructions into simpler forms
+// that do not require creating new instructions. This does constant folding
+// ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
+// returning a constant ("and i32 %x, 0" -> "0") or an already existing value
+// ("and i32 %x, %x" -> "%x"). If the simplification is also an instruction
+// then it dominates the original instruction.
+//
+// These routines implicitly resolve undef uses. The easiest way to be safe when
+// using these routines to obtain simplified values for existing instructions is
+// to always replace all uses of the instructions with the resulting simplified
+// values. This will prevent other code from seeing the same undef uses and
+// resolving them to different values.
+//
+// These routines are designed to tolerate moderately incomplete IR, such as
+// instructions that are not connected to basic blocks yet. However, they do
+// require that all the IR that they encounter be valid. In particular, they
+// require that all non-constant values be defined in the same function, and the
+// same call context of that function (and not split between caller and callee
+// contexts of a directly recursive call, for example).
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
+#include "llvm/IR/User.h"
+
namespace llvm {
+ template<typename T>
+ class ArrayRef;
+ class DominatorTree;
class Instruction;
+ class DataLayout;
+ class FastMathFlags;
+ class TargetLibraryInfo;
+ class Type;
class Value;
- class TargetData;
/// SimplifyAddInst - Given operands for an Add, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
- const TargetData *TD = 0);
-
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifySubInst - Given operands for a Sub, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// Given operands for an FAdd, see if we can fold the result. If not, this
+ /// returns null.
+ Value *SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// Given operands for an FSub, see if we can fold the result. If not, this
+ /// returns null.
+ Value *SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// Given operands for an FMul, see if we can fold the result. If not, this
+ /// returns null.
+ Value *SimplifyFMulInst(Value *LHS, Value *RHS,
+ FastMathFlags FMF,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyMulInst - Given operands for a Mul, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyMulInst(Value *LHS, Value *RHS, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifySDivInst - Given operands for an SDiv, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifySDivInst(Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyUDivInst - Given operands for a UDiv, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyUDivInst(Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyFDivInst - Given operands for an FDiv, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyFDivInst(Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifySRemInst - Given operands for an SRem, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifySRemInst(Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyURemInst - Given operands for a URem, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyURemInst(Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyFRemInst - Given operands for an FRem, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyFRemInst(Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyShlInst - Given operands for a Shl, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyLShrInst - Given operands for a LShr, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyAShrInst - Given operands for a AShr, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
/// SimplifyAndInst - Given operands for an And, see if we can
/// fold the result. If not, this returns null.
- Value *SimplifyAndInst(Value *LHS, Value *RHS,
- const TargetData *TD = 0);
+ Value *SimplifyAndInst(Value *LHS, Value *RHS, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
- Value *SimplifyOrInst(Value *LHS, Value *RHS,
- const TargetData *TD = 0);
-
+ Value *SimplifyOrInst(Value *LHS, Value *RHS, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyXorInst - Given operands for a Xor, see if we can
+ /// fold the result. If not, this returns null.
+ Value *SimplifyXorInst(Value *LHS, Value *RHS, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD = 0);
-
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD = 0);
-
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
/// the result. If not, this returns null.
Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
- const TargetData *TD = 0);
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
/// fold the result. If not, this returns null.
- Value *SimplifyGEPInst(Value * const *Ops, unsigned NumOps,
- const TargetData *TD = 0);
-
+ Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
+ /// can fold the result. If not, this returns null.
+ Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
+ ArrayRef<unsigned> Idxs,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// SimplifyTruncInst - Given operands for an TruncInst, see if we can fold
+ /// the result. If not, this returns null.
+ Value *SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
//=== Helper functions for higher up the class hierarchy.
-
-
+
+
/// SimplifyCmpInst - Given operands for a CmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD = 0);
-
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
/// fold the result. If not, this returns null.
- Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD = 0);
-
+ Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// \brief Given a function and iterators over arguments, see if we can fold
+ /// the result.
+ ///
+ /// If this call could not be simplified returns null.
+ Value *SimplifyCall(Value *V, User::op_iterator ArgBegin,
+ User::op_iterator ArgEnd, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// \brief Given a function and set of arguments, see if we can fold the
+ /// result.
+ ///
+ /// If this call could not be simplified returns null.
+ Value *SimplifyCall(Value *V, ArrayRef<Value *> Args,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
/// SimplifyInstruction - See if we can compute a simplified version of this
/// instruction. If not, this returns null.
- Value *SimplifyInstruction(Instruction *I, const TargetData *TD = 0);
-
-
- /// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then
- /// delete the From instruction. In addition to a basic RAUW, this does a
- /// recursive simplification of the updated instructions. This catches
- /// things where one simplification exposes other opportunities. This only
- /// simplifies and deletes scalar operations, it does not change the CFG.
+ Value *SimplifyInstruction(Instruction *I, const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+
+ /// \brief Replace all uses of 'I' with 'SimpleV' and simplify the uses
+ /// recursively.
+ ///
+ /// This first performs a normal RAUW of I with SimpleV. It then recursively
+ /// attempts to simplify those users updated by the operation. The 'I'
+ /// instruction must not be equal to the simplified value 'SimpleV'.
+ ///
+ /// The function returns true if any simplifications were performed.
+ bool replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
+
+ /// \brief Recursively attempt to simplify an instruction.
///
- void ReplaceAndSimplifyAllUses(Instruction *From, Value *To,
- const TargetData *TD = 0);
+ /// This routine uses SimplifyInstruction to simplify 'I', and if successful
+ /// replaces uses of 'I' with the simplified value. It then recurses on each
+ /// of the users impacted. It returns true if any simplifications were
+ /// performed.
+ bool recursivelySimplifyInstruction(Instruction *I,
+ const DataLayout *TD = nullptr,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr);
} // end namespace llvm
#endif