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Diffstat (limited to 'include/llvm/Analysis/InstructionSimplify.h')
-rw-r--r-- | include/llvm/Analysis/InstructionSimplify.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/llvm/Analysis/InstructionSimplify.h b/include/llvm/Analysis/InstructionSimplify.h new file mode 100644 index 0000000..aa5c0f5 --- /dev/null +++ b/include/llvm/Analysis/InstructionSimplify.h @@ -0,0 +1,74 @@ +//===-- InstructionSimplify.h - Fold instructions into simpler forms ------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// 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. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H +#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H + +namespace llvm { + class Instruction; + class Value; + class TargetData; + + /// 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); + + /// 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); + + /// 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); + + /// 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); + + + //=== 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); + + /// 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); + + /// 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. + /// + void ReplaceAndSimplifyAllUses(Instruction *From, Value *To, + const TargetData *TD = 0); +} // end namespace llvm + +#endif + |