1 //===- VPlanTransforms.h - Utility VPlan to VPlan transforms --------------===//
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 provides utility VPlan to VPlan transformations.
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
14 #define LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
15 
16 #include "VPlan.h"
17 #include "llvm/ADT/STLFunctionalExtras.h"
18 
19 namespace llvm {
20 
21 class InductionDescriptor;
22 class Instruction;
23 class PHINode;
24 class ScalarEvolution;
25 class Loop;
26 
27 struct VPlanTransforms {
28   /// Replaces the VPInstructions in \p Plan with corresponding
29   /// widen recipes.
30   static void
31   VPInstructionsToVPRecipes(Loop *OrigLoop, VPlanPtr &Plan,
32                             function_ref<const InductionDescriptor *(PHINode *)>
33                                 GetIntOrFpInductionDescriptor,
34                             SmallPtrSetImpl<Instruction *> &DeadInstructions,
35                             ScalarEvolution &SE);
36 
37   static bool sinkScalarOperands(VPlan &Plan);
38 
39   static bool mergeReplicateRegions(VPlan &Plan);
40 
41   /// Remove redundant casts of inductions.
42   ///
43   /// Such redundant casts are casts of induction variables that can be ignored,
44   /// because we already proved that the casted phi is equal to the uncasted phi
45   /// in the vectorized loop. There is no need to vectorize the cast - the same
46   /// value can be used for both the phi and casts in the vector loop.
47   static void removeRedundantInductionCasts(VPlan &Plan);
48 
49   /// Try to replace VPWidenCanonicalIVRecipes with a widened canonical IV
50   /// recipe, if it exists.
51   static void removeRedundantCanonicalIVs(VPlan &Plan);
52 
53   static void removeDeadRecipes(VPlan &Plan);
54 
55   /// If any user of a VPWidenIntOrFpInductionRecipe needs scalar values,
56   /// provide them by building scalar steps off of the canonical scalar IV and
57   /// update the original IV's users. This is an optional optimization to reduce
58   /// the needs of vector extracts.
59   static void optimizeInductions(VPlan &Plan, ScalarEvolution &SE);
60 
61   /// Remove redundant EpxandSCEVRecipes in \p Plan's entry block by replacing
62   /// them with already existing recipes expanding the same SCEV expression.
63   static void removeRedundantExpandSCEVRecipes(VPlan &Plan);
64 };
65 
66 } // namespace llvm
67 
68 #endif // LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
69