1 //===-- AMDGPUFixFunctionBitcasts.cpp - Fix function bitcasts -------------===//
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 /// Promote indirect (bitcast) calls to direct calls when they are statically
11 /// known to be direct. Required when InstCombine is not run (e.g. at OptNone)
12 /// because AMDGPU does not support indirect calls.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "AMDGPU.h"
17 #include "llvm/IR/InstVisitor.h"
18 #include "llvm/Pass.h"
19 #include "llvm/Transforms/Utils/CallPromotionUtils.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "amdgpu-fix-function-bitcasts"
24 
25 namespace {
26 class AMDGPUFixFunctionBitcasts final
27     : public ModulePass,
28       public InstVisitor<AMDGPUFixFunctionBitcasts> {
29 
30   bool runOnModule(Module &M) override;
31 
32   bool Modified;
33 
34 public:
visitCallBase(CallBase & CB)35   void visitCallBase(CallBase &CB) {
36     if (CB.getCalledFunction())
37       return;
38     auto *Callee =
39         dyn_cast<Function>(CB.getCalledOperand()->stripPointerCasts());
40     if (Callee && isLegalToPromote(CB, Callee)) {
41       promoteCall(CB, Callee);
42       Modified = true;
43     }
44   }
45 
46   static char ID;
AMDGPUFixFunctionBitcasts()47   AMDGPUFixFunctionBitcasts() : ModulePass(ID) {}
48 };
49 } // End anonymous namespace
50 
51 char AMDGPUFixFunctionBitcasts::ID = 0;
52 char &llvm::AMDGPUFixFunctionBitcastsID = AMDGPUFixFunctionBitcasts::ID;
53 INITIALIZE_PASS(AMDGPUFixFunctionBitcasts, DEBUG_TYPE,
54                 "Fix function bitcasts for AMDGPU", false, false)
55 
createAMDGPUFixFunctionBitcastsPass()56 ModulePass *llvm::createAMDGPUFixFunctionBitcastsPass() {
57   return new AMDGPUFixFunctionBitcasts();
58 }
59 
runOnModule(Module & M)60 bool AMDGPUFixFunctionBitcasts::runOnModule(Module &M) {
61   Modified = false;
62   visit(M);
63   return Modified;
64 }
65