LLVM  12.0.0git
GuardUtils.h
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1 //===-- GuardUtils.h - Utils for work with guards ---------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 // Utils that are used to perform transformations related to guards and their
9 // conditions.
10 //===----------------------------------------------------------------------===//
11 
12 #ifndef LLVM_TRANSFORMS_UTILS_GUARDUTILS_H
13 #define LLVM_TRANSFORMS_UTILS_GUARDUTILS_H
14 
15 namespace llvm {
16 
17 class BranchInst;
18 class CallInst;
19 class Function;
20 class Value;
21 
22 /// Splits control flow at point of \p Guard, replacing it with explicit branch
23 /// by the condition of guard's first argument. The taken branch then goes to
24 /// the block that contains \p Guard's successors, and the non-taken branch
25 /// goes to a newly-created deopt block that contains a sole call of the
26 /// deoptimize function \p DeoptIntrinsic. If 'UseWC' is set, preserve the
27 /// widenable nature of the guard by lowering to equivelent form. If not set,
28 /// lower to a form without widenable semantics.
29 void makeGuardControlFlowExplicit(Function *DeoptIntrinsic, CallInst *Guard,
30  bool UseWC);
31 
32 /// Given a branch we know is widenable (defined per Analysis/GuardUtils.h),
33 /// widen it such that condition 'NewCond' is also known to hold on the taken
34 /// path. Branch remains widenable after transform.
35 void widenWidenableBranch(BranchInst *WidenableBR, Value *NewCond);
36 
37 /// Given a branch we know is widenable (defined per Analysis/GuardUtils.h),
38 /// *set* it's condition such that (only) 'Cond' is known to hold on the taken
39 /// path and that the branch remains widenable after transform.
40 void setWidenableBranchCond(BranchInst *WidenableBR, Value *Cond);
41 
42 } // llvm
43 
44 #endif // LLVM_TRANSFORMS_UTILS_GUARDUTILS_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
void setWidenableBranchCond(BranchInst *WidenableBR, Value *Cond)
Given a branch we know is widenable (defined per Analysis/GuardUtils.h), set it's condition such that...
Definition: GuardUtils.cpp:108
SmallVector< MachineOperand, 4 > Cond
void widenWidenableBranch(BranchInst *WidenableBR, Value *NewCond)
Given a branch we know is widenable (defined per Analysis/GuardUtils.h), widen it such that condition...
Definition: GuardUtils.cpp:82
void makeGuardControlFlowExplicit(Function *DeoptIntrinsic, CallInst *Guard, bool UseWC)
Splits control flow at point of Guard, replacing it with explicit branch by the condition of guard&#39;s ...
Definition: GuardUtils.cpp:30