1 //===- CallPromotionUtils.h - Utilities for call promotion ------*- 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 declares utilities useful for promoting indirect call sites to
11 // direct call sites.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_TRANSFORMS_UTILS_CALLPROMOTIONUTILS_H
16 #define LLVM_TRANSFORMS_UTILS_CALLPROMOTIONUTILS_H
17 
18 #include "llvm/IR/CallSite.h"
19 
20 namespace llvm {
21 
22 /// Return true if the given indirect call site can be made to call \p Callee.
23 ///
24 /// This function ensures that the number and type of the call site's arguments
25 /// and return value match those of the given function. If the types do not
26 /// match exactly, they must at least be bitcast compatible. If \p FailureReason
27 /// is non-null and the indirect call cannot be promoted, the failure reason
28 /// will be stored in it.
29 bool isLegalToPromote(CallSite CS, Function *Callee,
30                       const char **FailureReason = nullptr);
31 
32 /// Promote the given indirect call site to unconditionally call \p Callee.
33 ///
34 /// This function promotes the given call site, returning the direct call or
35 /// invoke instruction. If the function type of the call site doesn't match that
36 /// of the callee, bitcast instructions are inserted where appropriate. If \p
37 /// RetBitCast is non-null, it will be used to store the return value bitcast,
38 /// if created.
39 Instruction *promoteCall(CallSite CS, Function *Callee,
40                          CastInst **RetBitCast = nullptr);
41 
42 /// Promote the given indirect call site to conditionally call \p Callee.
43 ///
44 /// This function creates an if-then-else structure at the location of the call
45 /// site. The original call site is moved into the "else" block. A clone of the
46 /// indirect call site is promoted, placed in the "then" block, and returned. If
47 /// \p BranchWeights is non-null, it will be used to set !prof metadata on the
48 /// new conditional branch.
49 Instruction *promoteCallWithIfThenElse(CallSite CS, Function *Callee,
50                                        MDNode *BranchWeights = nullptr);
51 
52 } // end namespace llvm
53 
54 #endif // LLVM_TRANSFORMS_UTILS_CALLPROMOTIONUTILS_H
55