Home | History | Annotate | Download | only in compiler 
      1 /*
      2  * Copyright 2017, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "RemoveNonkernelsPass.h"
     18 
     19 #include "llvm/ADT/Triple.h"
     20 #include "llvm/IR/Constants.h"
     21 #include "llvm/IR/Module.h"
     22 #include "llvm/Pass.h"
     23 #include "llvm/Support/Debug.h"
     24 #include "llvm/Support/raw_ostream.h"
     25 
     26 #include "Context.h"
     27 
     28 #define DEBUG_TYPE "rs2spirv-remove"
     29 
     30 using namespace llvm;
     31 
     32 namespace rs2spirv {
     33 
     34 namespace {
     35 
     36 void HandleTargetTriple(llvm::Module &M) {
     37   Triple TT(M.getTargetTriple());
     38   auto Arch = TT.getArch();
     39 
     40   StringRef NewTriple;
     41   switch (Arch) {
     42   default:
     43     llvm_unreachable("Unrecognized architecture");
     44     break;
     45   case Triple::arm:
     46     NewTriple = "spir-unknown-unknown";
     47     break;
     48   case Triple::aarch64:
     49     NewTriple = "spir64-unknown-unknown";
     50     break;
     51   case Triple::spir:
     52   case Triple::spir64:
     53     DEBUG(dbgs() << "!!! Already a spir triple !!!\n");
     54   }
     55 
     56   DEBUG(dbgs() << "New triple:\t" << NewTriple << "\n");
     57   M.setTargetTriple(NewTriple);
     58 }
     59 
     60 class RemoveNonkernelsPass : public ModulePass {
     61 public:
     62   static char ID;
     63   explicit RemoveNonkernelsPass() : ModulePass(ID) {}
     64 
     65   const char *getPassName() const override { return "RemoveNonkernelsPass"; }
     66 
     67   bool runOnModule(Module &M) override {
     68     DEBUG(dbgs() << "RemoveNonkernelsPass\n");
     69     DEBUG(M.dump());
     70 
     71     HandleTargetTriple(M);
     72 
     73     rs2spirv::Context &Ctxt = rs2spirv::Context::getInstance();
     74 
     75     if (Ctxt.getNumForEachKernel() == 0) {
     76       DEBUG(dbgs() << "RemoveNonkernelsPass detected no kernel\n");
     77       // Returns false, since no modification is made to the Module.
     78       return false;
     79     }
     80 
     81     std::vector<Function *> Functions;
     82     for (auto &F : M.functions()) {
     83       Functions.push_back(&F);
     84     }
     85 
     86     for (auto &F : Functions) {
     87       if (F->isDeclaration())
     88         continue;
     89 
     90       if (Ctxt.isForEachKernel(F->getName())) {
     91         continue; // Skip kernels.
     92       }
     93 
     94       F->replaceAllUsesWith(UndefValue::get((Type *)F->getType()));
     95       F->eraseFromParent();
     96 
     97       DEBUG(dbgs() << "Removed:\t" << F->getName() << '\n');
     98     }
     99 
    100     DEBUG(M.dump());
    101     DEBUG(dbgs() << "Done removal\n");
    102 
    103     // Returns true, because the pass modifies the Module.
    104     return true;
    105   }
    106 };
    107 
    108 } // namespace
    109 
    110 char RemoveNonkernelsPass::ID = 0;
    111 
    112 ModulePass *createRemoveNonkernelsPass() {
    113   return new RemoveNonkernelsPass();
    114 }
    115 
    116 } // namespace rs2spirv
    117