1//===-- VPlanHCFGBuilder.h --------------------------------------*- 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///
9/// \file
10/// This file defines the VPlanHCFGBuilder class which contains the public
11/// interface (buildHierarchicalCFG) to build a VPlan-based Hierarchical CFG
12/// (H-CFG) for an incoming IR.
13///
14/// A H-CFG in VPlan is a control-flow graph whose nodes are VPBasicBlocks
15/// and/or VPRegionBlocks (i.e., other H-CFGs). The outermost H-CFG of a VPlan
16/// consists of a VPRegionBlock, denoted Top Region, which encloses any other
17/// VPBlockBase in the H-CFG. This guarantees that any VPBlockBase in the H-CFG
18/// other than the Top Region will have a parent VPRegionBlock and allows us
19/// to easily add more nodes before/after the main vector loop (such as the
20/// reduction epilogue).
21///
22//===----------------------------------------------------------------------===//
23
24#ifndef LLVM_TRANSFORMS_VECTORIZE_VPLAN_VPLANHCFGBUILDER_H
25#define LLVM_TRANSFORMS_VECTORIZE_VPLAN_VPLANHCFGBUILDER_H
26
27#include "VPlanDominatorTree.h"
28
29namespace llvm {
30
31class Loop;
32class LoopInfo;
33class VPRegionBlock;
34class VPlan;
35class VPlanTestBase;
36
37/// Main class to build the VPlan H-CFG for an incoming IR.
38class VPlanHCFGBuilder {
39 friend VPlanTestBase;
40
41private:
42 // The outermost loop of the input loop nest considered for vectorization.
43 Loop *TheLoop;
44
45 // Loop Info analysis.
46 LoopInfo *LI;
47
48 // The VPlan that will contain the H-CFG we are building.
49 VPlan &Plan;
50
51 // Dominator analysis for VPlan plain CFG to be used in the
52 // construction of the H-CFG. This analysis is no longer valid once regions
53 // are introduced.
54 VPDominatorTree VPDomTree;
55
56 /// Build plain CFG for TheLoop and connects it to Plan's entry.
57 void buildPlainCFG();
58
59public:
60 VPlanHCFGBuilder(Loop *Lp, LoopInfo *LI, VPlan &P)
61 : TheLoop(Lp), LI(LI), Plan(P) {}
62
63 /// Build H-CFG for TheLoop and update Plan accordingly.
64 void buildHierarchicalCFG();
65};
66} // namespace llvm
67
68#endif // LLVM_TRANSFORMS_VECTORIZE_VPLAN_VPLANHCFGBUILDER_H
69