xref: /freebsd/contrib/llvm-project/llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.h (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
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 
29 namespace llvm {
30 
31 class Loop;
32 class LoopInfo;
33 class VPRegionBlock;
34 class VPlan;
35 class VPlanTestBase;
36 
37 /// Main class to build the VPlan H-CFG for an incoming IR.
38 class VPlanHCFGBuilder {
39   friend VPlanTestBase;
40 
41 private:
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 This analysis is no longer valid once regions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 
59 public:
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