From 0b57cec536236d46e3dba9bd041533462f33dbb7 Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Fri, 20 Dec 2019 19:53:05 +0000 Subject: Move all sources from the llvm project into contrib/llvm-project. This uses the new layout of the upstream repository, which was recently migrated to GitHub, and converted into a "monorepo". That is, most of the earlier separate sub-projects with their own branches and tags were consolidated into one top-level directory, and are now branched and tagged together. Updating the vendor area to match this layout is next. --- .../llvm/lib/Transforms/Utils/GuardUtils.cpp | 63 ++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 contrib/llvm-project/llvm/lib/Transforms/Utils/GuardUtils.cpp (limited to 'contrib/llvm-project/llvm/lib/Transforms/Utils/GuardUtils.cpp') diff --git a/contrib/llvm-project/llvm/lib/Transforms/Utils/GuardUtils.cpp b/contrib/llvm-project/llvm/lib/Transforms/Utils/GuardUtils.cpp new file mode 100644 index 000000000000..34c32d9c0c98 --- /dev/null +++ b/contrib/llvm-project/llvm/lib/Transforms/Utils/GuardUtils.cpp @@ -0,0 +1,63 @@ +//===-- GuardUtils.cpp - Utils for work with guards -------------*- C++ -*-===// +// +// 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 +// +//===----------------------------------------------------------------------===// +// Utils that are used to perform transformations related to guards and their +// conditions. +//===----------------------------------------------------------------------===// + +#include "llvm/Transforms/Utils/GuardUtils.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/MDBuilder.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" + +using namespace llvm; + +static cl::opt PredicatePassBranchWeight( + "guards-predicate-pass-branch-weight", cl::Hidden, cl::init(1 << 20), + cl::desc("The probability of a guard failing is assumed to be the " + "reciprocal of this value (default = 1 << 20)")); + +void llvm::makeGuardControlFlowExplicit(Function *DeoptIntrinsic, + CallInst *Guard) { + OperandBundleDef DeoptOB(*Guard->getOperandBundle(LLVMContext::OB_deopt)); + SmallVector Args(std::next(Guard->arg_begin()), Guard->arg_end()); + + auto *CheckBB = Guard->getParent(); + auto *DeoptBlockTerm = + SplitBlockAndInsertIfThen(Guard->getArgOperand(0), Guard, true); + + auto *CheckBI = cast(CheckBB->getTerminator()); + + // SplitBlockAndInsertIfThen inserts control flow that branches to + // DeoptBlockTerm if the condition is true. We want the opposite. + CheckBI->swapSuccessors(); + + CheckBI->getSuccessor(0)->setName("guarded"); + CheckBI->getSuccessor(1)->setName("deopt"); + + if (auto *MD = Guard->getMetadata(LLVMContext::MD_make_implicit)) + CheckBI->setMetadata(LLVMContext::MD_make_implicit, MD); + + MDBuilder MDB(Guard->getContext()); + CheckBI->setMetadata(LLVMContext::MD_prof, + MDB.createBranchWeights(PredicatePassBranchWeight, 1)); + + IRBuilder<> B(DeoptBlockTerm); + auto *DeoptCall = B.CreateCall(DeoptIntrinsic, Args, {DeoptOB}, ""); + + if (DeoptIntrinsic->getReturnType()->isVoidTy()) { + B.CreateRetVoid(); + } else { + DeoptCall->setName("deoptcall"); + B.CreateRet(DeoptCall); + } + + DeoptCall->setCallingConv(Guard->getCallingConv()); + DeoptBlockTerm->eraseFromParent(); +} -- cgit v1.2.3