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//=== WebAssemblyLowerRefTypesIntPtrConv.cpp -
// Lower IntToPtr and PtrToInt on Reference Types ---===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Lowers IntToPtr and PtrToInt instructions on reference types to
/// Trap instructions since they have been allowed to operate
/// on non-integral pointers.
///
//===----------------------------------------------------------------------===//
#include "Utils/WebAssemblyTypeUtilities.h"
#include "WebAssembly.h"
#include "WebAssemblySubtarget.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/Pass.h"
using namespace llvm;
#define DEBUG_TYPE "wasm-lower-reftypes-intptr-conv"
namespace {
class WebAssemblyLowerRefTypesIntPtrConv final : public FunctionPass {
StringRef getPassName() const override {
return "WebAssembly Lower RefTypes Int-Ptr Conversions";
}
bool runOnFunction(Function &MF) override;
public:
static char ID; // Pass identification
WebAssemblyLowerRefTypesIntPtrConv() : FunctionPass(ID) {}
};
} // end anonymous namespace
char WebAssemblyLowerRefTypesIntPtrConv::ID = 0;
INITIALIZE_PASS(WebAssemblyLowerRefTypesIntPtrConv, DEBUG_TYPE,
"WebAssembly Lower RefTypes Int-Ptr Conversions", false, false)
FunctionPass *llvm::createWebAssemblyLowerRefTypesIntPtrConv() {
return new WebAssemblyLowerRefTypesIntPtrConv();
}
bool WebAssemblyLowerRefTypesIntPtrConv::runOnFunction(Function &F) {
LLVM_DEBUG(dbgs() << "********** Lower RefTypes IntPtr Convs **********\n"
"********** Function: "
<< F.getName() << '\n');
// This function will check for uses of ptrtoint and inttoptr on reference
// types and replace them with a trap instruction.
//
// We replace the instruction by a trap instruction
// and its uses by null in the case of inttoptr and 0 in the
// case of ptrtoint.
std::set<Instruction *> worklist;
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
PtrToIntInst *PTI = dyn_cast<PtrToIntInst>(&*I);
IntToPtrInst *ITP = dyn_cast<IntToPtrInst>(&*I);
if (!(PTI && WebAssembly::isRefType(PTI->getPointerOperand()->getType())) &&
!(ITP && WebAssembly::isRefType(ITP->getDestTy())))
continue;
UndefValue *U = UndefValue::get(I->getType());
I->replaceAllUsesWith(U);
Function *TrapIntrin =
Intrinsic::getDeclaration(F.getParent(), Intrinsic::debugtrap);
CallInst::Create(TrapIntrin, {}, "", &*I);
worklist.insert(&*I);
}
// erase each instruction replaced by trap
for (Instruction *I : worklist)
I->eraseFromParent();
return !worklist.empty();
}
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