1 //===------- LoopBoundSplit.h - Split Loop Bound ----------------*- 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 #ifndef LLVM_TRANSFORMS_SCALAR_LOOPBOUNDSPLIT_H
10 #define LLVM_TRANSFORMS_SCALAR_LOOPBOUNDSPLIT_H
11 
12 #include "llvm/Analysis/LoopAnalysisManager.h"
13 #include "llvm/Analysis/LoopInfo.h"
14 #include "llvm/IR/PassManager.h"
15 #include "llvm/Transforms/Scalar/LoopPassManager.h"
16 
17 namespace llvm {
18 
19 /// This pass transforms loops that contain a conditional branch with induction
20 /// variable. For example, it transforms left code to right code:
21 ///
22 ///                              newbound = min(n, c)
23 ///  while (iv < n) {            while(iv < newbound) {
24 ///    A                           A
25 ///    if (iv < c)                 B
26 ///      B                         C
27 ///    C                         }
28 ///                              if (iv != n) {
29 ///                                while (iv < n) {
30 ///                                  A
31 ///                                  C
32 ///                                }
33 ///                              }
34 class LoopBoundSplitPass : public PassInfoMixin<LoopBoundSplitPass> {
35 public:
36   PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
37                         LoopStandardAnalysisResults &AR, LPMUpdater &U);
38 };
39 
40 } // end namespace llvm
41 
42 #endif // LLVM_TRANSFORMS_SCALAR_LOOPBOUNDSPLIT_H
43