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//===-- GuardUtils.h - Utils for work with guards ---------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

// Utils that are used to perform transformations related to guards and their

// conditions.

//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_UTILS_GUARDUTILS_H

#define LLVM_TRANSFORMS_UTILS_GUARDUTILS_H

namespace llvm {

class BranchInst;

class CallInst;

class Function;

class Value;

/// Splits control flow at point of \p Guard, replacing it with explicit branch

/// by the condition of guard's first argument. The taken branch then goes to

/// the block that contains  \p Guard's successors, and the non-taken branch

/// goes to a newly-created deopt block that contains a sole call of the

/// deoptimize function \p DeoptIntrinsic.  If 'UseWC' is set, preserve the

/// widenable nature of the guard by lowering to equivelent form.  If not set,

/// lower to a form without widenable semantics.

void makeGuardControlFlowExplicit(Function *DeoptIntrinsic, CallInst *Guard,

                                  bool UseWC);

/// Given a branch we know is widenable (defined per Analysis/GuardUtils.h),

/// widen it such that condition 'NewCond' is also known to hold on the taken

/// path.  Branch remains widenable after transform.

void widenWidenableBranch(BranchInst *WidenableBR, Value *NewCond);

/// Given a branch we know is widenable (defined per Analysis/GuardUtils.h),

/// *set* it's condition such that (only) 'Cond' is known to hold on the taken

/// path and that the branch remains widenable after transform.

void setWidenableBranchCond(BranchInst *WidenableBR, Value *Cond);

} // llvm

#endif // LLVM_TRANSFORMS_UTILS_GUARDUTILS_H