llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.h

   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 This analysis is no longer valid once regions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