LLVM 20.0.0git
MakeGuardsExplicit.h
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1//===-- MakeGuardsExplicit.h - Turn guard intrinsics into guard branches --===//
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//
9// This pass lowers the @llvm.experimental.guard intrinsic to the new form of
10// guard represented as widenable explicit branch to the deopt block. The
11// difference between this pass and LowerGuardIntrinsic is that after this pass
12// the guard represented as intrinsic:
13//
14// call void(i1, ...) @llvm.experimental.guard(i1 %old_cond) [ "deopt"() ]
15//
16// transforms to a guard represented as widenable explicit branch:
17//
18// %widenable_cond = call i1 @llvm.experimental.widenable.condition()
19// br i1 (%old_cond & %widenable_cond), label %guarded, label %deopt
20//
21// Here:
22// - The semantics of @llvm.experimental.widenable.condition allows to replace
23// %widenable_cond with the construction (%widenable_cond & %any_other_cond)
24// without loss of correctness;
25// - %guarded is the lower part of old guard intrinsic's parent block split by
26// the intrinsic call;
27// - %deopt is a block containing a sole call to @llvm.experimental.deoptimize
28// intrinsic.
29//
30// Therefore, this branch preserves the property of widenability.
31//
32//===----------------------------------------------------------------------===//
33#ifndef LLVM_TRANSFORMS_SCALAR_MAKEGUARDSEXPLICIT_H
34#define LLVM_TRANSFORMS_SCALAR_MAKEGUARDSEXPLICIT_H
35
36#include "llvm/IR/PassManager.h"
37
38namespace llvm {
39
40struct MakeGuardsExplicitPass : public PassInfoMixin<MakeGuardsExplicitPass> {
42};
43
44} // namespace llvm
45
46#endif // LLVM_TRANSFORMS_SCALAR_MAKEGUARDSEXPLICIT_H
#define F(x, y, z)
Definition: MD5.cpp:55
This header defines various interfaces for pass management in LLVM.
A container for analyses that lazily runs them and caches their results.
Definition: PassManager.h:253
A set of analyses that are preserved following a run of a transformation pass.
Definition: Analysis.h:111
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:69