Transforms/Scalar/LoopBoundSplit.h

0001 //===------- LoopBoundSplit.h - Split Loop Bound ----------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef LLVM_TRANSFORMS_SCALAR_LOOPBOUNDSPLIT_H
0010 #define LLVM_TRANSFORMS_SCALAR_LOOPBOUNDSPLIT_H
0011
0012 #include "llvm/Analysis/LoopAnalysisManager.h"
0013 #include "llvm/IR/PassManager.h"
0014
0015 namespace llvm {
0016 class LPMUpdater;
0017 class Loop;
0018
0019 /// This pass transforms loops that contain a conditional branch with induction
0020 /// variable. For example, it transforms left code to right code:
0021 ///
0022 ///                              newbound = min(n, c)
0023 ///  while (iv < n) {            while(iv < newbound) {
0024 ///    A                           A
0025 ///    if (iv < c)                 B
0026 ///      B                         C
0027 ///    C                         }
0028 ///                              if (iv != n) {
0029 ///                                while (iv < n) {
0030 ///                                  A
0031 ///                                  C
0032 ///                                }
0033 ///                              }
0034 class LoopBoundSplitPass : public PassInfoMixin<LoopBoundSplitPass> {
0035 public:
0036   PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
0037                         LoopStandardAnalysisResults &AR, LPMUpdater &U);
0038 };
0039
0040 } // end namespace llvm
0041
0042 #endif // LLVM_TRANSFORMS_SCALAR_LOOPBOUNDSPLIT_H