1 //===---- AlignmentFromAssumptions.h ----------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements a ScalarEvolution-based transformation to set
11 // the alignments of load, stores and memory intrinsics based on the truth
12 // expressions of assume intrinsics. The primary motivation is to handle
13 // complex alignment assumptions that apply to vector loads and stores that
14 // appear after vectorization and unrolling.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_TRANSFORMS_SCALAR_ALIGNMENTFROMASSUMPTIONS_H
19 #define LLVM_TRANSFORMS_SCALAR_ALIGNMENTFROMASSUMPTIONS_H
20 
21 #include "llvm/Analysis/ScalarEvolution.h"
22 #include "llvm/IR/Function.h"
23 #include "llvm/IR/IntrinsicInst.h"
24 #include "llvm/IR/PassManager.h"
25 
26 namespace llvm {
27 
28 struct AlignmentFromAssumptionsPass
29     : public PassInfoMixin<AlignmentFromAssumptionsPass> {
30   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
31 
32   // Glue for old PM.
33   bool runImpl(Function &F, AssumptionCache &AC, ScalarEvolution *SE_,
34                DominatorTree *DT_);
35 
36   // For memory transfers, we need a common alignment for both the source and
37   // destination. If we have a new alignment for only one operand of a transfer
38   // instruction, save it in these maps.  If we reach the other operand through
39   // another assumption later, then we may change the alignment at that point.
40   DenseMap<MemTransferInst *, unsigned> NewDestAlignments, NewSrcAlignments;
41 
42   ScalarEvolution *SE = nullptr;
43   DominatorTree *DT = nullptr;
44 
45   bool extractAlignmentInfo(CallInst *I, Value *&AAPtr, const SCEV *&AlignSCEV,
46                             const SCEV *&OffSCEV);
47   bool processAssumption(CallInst *I);
48 };
49 }
50 
51 #endif // LLVM_TRANSFORMS_SCALAR_ALIGNMENTFROMASSUMPTIONS_H
52