[llvm] r365532 - [BPF] Fix a typo in the file name
Yonghong Song via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 9 11:35:46 PDT 2019
Author: yhs
Date: Tue Jul 9 11:35:46 2019
New Revision: 365532
URL: http://llvm.org/viewvc/llvm-project?rev=365532&view=rev
Log:
[BPF] Fix a typo in the file name
Fixed the file name from BPFAbstrctMemberAccess.cpp to
BPFAbstractMemberAccess.cpp.
Signed-off-by: Yonghong Song <yhs at fb.com>
Added:
llvm/trunk/lib/Target/BPF/BPFAbstractMemberAccess.cpp
- copied, changed from r365530, llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp
Removed:
llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp
Modified:
llvm/trunk/lib/Target/BPF/CMakeLists.txt
Copied: llvm/trunk/lib/Target/BPF/BPFAbstractMemberAccess.cpp (from r365530, llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/BPFAbstractMemberAccess.cpp?p2=llvm/trunk/lib/Target/BPF/BPFAbstractMemberAccess.cpp&p1=llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp&r1=365530&r2=365532&rev=365532&view=diff
==============================================================================
(empty)
Removed: llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp?rev=365531&view=auto
==============================================================================
--- llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp (original)
+++ llvm/trunk/lib/Target/BPF/BPFAbstrctMemberAccess.cpp (removed)
@@ -1,482 +0,0 @@
-//===------ BPFAbstractMemberAccess.cpp - Abstracting Member Accesses -----===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass abstracted struct/union member accesses in order to support
-// compile-once run-everywhere (CO-RE). The CO-RE intends to compile the program
-// which can run on different kernels. In particular, if bpf program tries to
-// access a particular kernel data structure member, the details of the
-// intermediate member access will be remembered so bpf loader can do
-// necessary adjustment right before program loading.
-//
-// For example,
-//
-// struct s {
-// int a;
-// int b;
-// };
-// struct t {
-// struct s c;
-// int d;
-// };
-// struct t e;
-//
-// For the member access e.c.b, the compiler will generate code
-// &e + 4
-//
-// The compile-once run-everywhere instead generates the following code
-// r = 4
-// &e + r
-// The "4" in "r = 4" can be changed based on a particular kernel version.
-// For example, on a particular kernel version, if struct s is changed to
-//
-// struct s {
-// int new_field;
-// int a;
-// int b;
-// }
-//
-// By repeating the member access on the host, the bpf loader can
-// adjust "r = 4" as "r = 8".
-//
-// This feature relies on the following three intrinsic calls:
-// addr = preserve_array_access_index(base, dimension, index)
-// addr = preserve_union_access_index(base, di_index)
-// !llvm.preserve.access.index <union_ditype>
-// addr = preserve_struct_access_index(base, gep_index, di_index)
-// !llvm.preserve.access.index <struct_ditype>
-//
-//===----------------------------------------------------------------------===//
-
-#include "BPF.h"
-#include "BPFCORE.h"
-#include "BPFTargetMachine.h"
-#include "llvm/IR/DebugInfoMetadata.h"
-#include "llvm/IR/GlobalVariable.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/User.h"
-#include "llvm/IR/Value.h"
-#include "llvm/Pass.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-
-#define DEBUG_TYPE "bpf-abstract-member-access"
-
-namespace llvm {
-const std::string BPFCoreSharedInfo::AmaAttr = "btf_ama";
-const std::string BPFCoreSharedInfo::PatchableExtSecName =
- ".BPF.patchable_externs";
-} // namespace llvm
-
-using namespace llvm;
-
-namespace {
-
-class BPFAbstractMemberAccess final : public ModulePass {
- StringRef getPassName() const override {
- return "BPF Abstract Member Access";
- }
-
- bool runOnModule(Module &M) override;
-
-public:
- static char ID;
- BPFAbstractMemberAccess() : ModulePass(ID) {}
-
-private:
- enum : uint32_t {
- BPFPreserveArrayAI = 1,
- BPFPreserveUnionAI = 2,
- BPFPreserveStructAI = 3,
- };
-
- std::map<std::string, GlobalVariable *> GEPGlobals;
- // A map to link preserve_*_access_index instrinsic calls.
- std::map<CallInst *, std::pair<CallInst *, uint32_t>> AIChain;
- // A map to hold all the base preserve_*_access_index instrinsic calls.
- // The base call is not an input of any other preserve_*_access_index
- // intrinsics.
- std::map<CallInst *, uint32_t> BaseAICalls;
-
- bool doTransformation(Module &M);
-
- void traceAICall(CallInst *Call, uint32_t Kind);
- void traceBitCast(BitCastInst *BitCast, CallInst *Parent, uint32_t Kind);
- void traceGEP(GetElementPtrInst *GEP, CallInst *Parent, uint32_t Kind);
- void collectAICallChains(Module &M, Function &F);
-
- bool IsPreserveDIAccessIndexCall(const CallInst *Call, uint32_t &Kind);
- bool removePreserveAccessIndexIntrinsic(Module &M);
- void replaceWithGEP(std::vector<CallInst *> &CallList,
- uint32_t NumOfZerosIndex, uint32_t DIIndex);
-
- Value *computeBaseAndAccessStr(CallInst *Call, std::string &AccessStr,
- std::string &AccessKey, uint32_t Kind,
- MDNode *&TypeMeta);
- bool getAccessIndex(const Value *IndexValue, uint64_t &AccessIndex);
- bool transformGEPChain(Module &M, CallInst *Call, uint32_t Kind);
-};
-} // End anonymous namespace
-
-char BPFAbstractMemberAccess::ID = 0;
-INITIALIZE_PASS(BPFAbstractMemberAccess, DEBUG_TYPE,
- "abstracting struct/union member accessees", false, false)
-
-ModulePass *llvm::createBPFAbstractMemberAccess() {
- return new BPFAbstractMemberAccess();
-}
-
-bool BPFAbstractMemberAccess::runOnModule(Module &M) {
- LLVM_DEBUG(dbgs() << "********** Abstract Member Accesses **********\n");
-
- // Bail out if no debug info.
- if (empty(M.debug_compile_units()))
- return false;
-
- return doTransformation(M);
-}
-
-/// Check whether a call is a preserve_*_access_index intrinsic call or not.
-bool BPFAbstractMemberAccess::IsPreserveDIAccessIndexCall(const CallInst *Call,
- uint32_t &Kind) {
- if (!Call)
- return false;
-
- const auto *GV = dyn_cast<GlobalValue>(Call->getCalledValue());
- if (!GV)
- return false;
- if (GV->getName().startswith("llvm.preserve.array.access.index")) {
- Kind = BPFPreserveArrayAI;
- return true;
- }
- if (GV->getName().startswith("llvm.preserve.union.access.index")) {
- Kind = BPFPreserveUnionAI;
- return true;
- }
- if (GV->getName().startswith("llvm.preserve.struct.access.index")) {
- Kind = BPFPreserveStructAI;
- return true;
- }
-
- return false;
-}
-
-void BPFAbstractMemberAccess::replaceWithGEP(std::vector<CallInst *> &CallList,
- uint32_t DimensionIndex,
- uint32_t GEPIndex) {
- for (auto Call : CallList) {
- uint32_t Dimension = 1;
- if (DimensionIndex > 0)
- Dimension = cast<ConstantInt>(Call->getArgOperand(DimensionIndex))
- ->getZExtValue();
-
- Constant *Zero =
- ConstantInt::get(Type::getInt32Ty(Call->getParent()->getContext()), 0);
- SmallVector<Value *, 4> IdxList;
- for (unsigned I = 0; I < Dimension; ++I)
- IdxList.push_back(Zero);
- IdxList.push_back(Call->getArgOperand(GEPIndex));
-
- auto *GEP = GetElementPtrInst::CreateInBounds(Call->getArgOperand(0),
- IdxList, "", Call);
- Call->replaceAllUsesWith(GEP);
- Call->eraseFromParent();
- }
-}
-
-bool BPFAbstractMemberAccess::removePreserveAccessIndexIntrinsic(Module &M) {
- std::vector<CallInst *> PreserveArrayIndexCalls;
- std::vector<CallInst *> PreserveUnionIndexCalls;
- std::vector<CallInst *> PreserveStructIndexCalls;
- bool Found = false;
-
- for (Function &F : M)
- for (auto &BB : F)
- for (auto &I : BB) {
- auto *Call = dyn_cast<CallInst>(&I);
- uint32_t Kind;
- if (!IsPreserveDIAccessIndexCall(Call, Kind))
- continue;
-
- Found = true;
- if (Kind == BPFPreserveArrayAI)
- PreserveArrayIndexCalls.push_back(Call);
- else if (Kind == BPFPreserveUnionAI)
- PreserveUnionIndexCalls.push_back(Call);
- else
- PreserveStructIndexCalls.push_back(Call);
- }
-
- // do the following transformation:
- // . addr = preserve_array_access_index(base, dimension, index)
- // is transformed to
- // addr = GEP(base, dimenion's zero's, index)
- // . addr = preserve_union_access_index(base, di_index)
- // is transformed to
- // addr = base, i.e., all usages of "addr" are replaced by "base".
- // . addr = preserve_struct_access_index(base, gep_index, di_index)
- // is transformed to
- // addr = GEP(base, 0, gep_index)
- replaceWithGEP(PreserveArrayIndexCalls, 1, 2);
- replaceWithGEP(PreserveStructIndexCalls, 0, 1);
- for (auto Call : PreserveUnionIndexCalls) {
- Call->replaceAllUsesWith(Call->getArgOperand(0));
- Call->eraseFromParent();
- }
-
- return Found;
-}
-
-void BPFAbstractMemberAccess::traceAICall(CallInst *Call, uint32_t Kind) {
- for (User *U : Call->users()) {
- Instruction *Inst = dyn_cast<Instruction>(U);
- if (!Inst)
- continue;
-
- if (auto *BI = dyn_cast<BitCastInst>(Inst)) {
- traceBitCast(BI, Call, Kind);
- } else if (auto *CI = dyn_cast<CallInst>(Inst)) {
- uint32_t CIKind;
- if (IsPreserveDIAccessIndexCall(CI, CIKind)) {
- AIChain[CI] = std::make_pair(Call, Kind);
- traceAICall(CI, CIKind);
- } else {
- BaseAICalls[Call] = Kind;
- }
- } else if (auto *GI = dyn_cast<GetElementPtrInst>(Inst)) {
- if (GI->hasAllZeroIndices())
- traceGEP(GI, Call, Kind);
- else
- BaseAICalls[Call] = Kind;
- }
- }
-}
-
-void BPFAbstractMemberAccess::traceBitCast(BitCastInst *BitCast,
- CallInst *Parent, uint32_t Kind) {
- for (User *U : BitCast->users()) {
- Instruction *Inst = dyn_cast<Instruction>(U);
- if (!Inst)
- continue;
-
- if (auto *BI = dyn_cast<BitCastInst>(Inst)) {
- traceBitCast(BI, Parent, Kind);
- } else if (auto *CI = dyn_cast<CallInst>(Inst)) {
- uint32_t CIKind;
- if (IsPreserveDIAccessIndexCall(CI, CIKind)) {
- AIChain[CI] = std::make_pair(Parent, Kind);
- traceAICall(CI, CIKind);
- } else {
- BaseAICalls[Parent] = Kind;
- }
- } else if (auto *GI = dyn_cast<GetElementPtrInst>(Inst)) {
- if (GI->hasAllZeroIndices())
- traceGEP(GI, Parent, Kind);
- else
- BaseAICalls[Parent] = Kind;
- }
- }
-}
-
-void BPFAbstractMemberAccess::traceGEP(GetElementPtrInst *GEP, CallInst *Parent,
- uint32_t Kind) {
- for (User *U : GEP->users()) {
- Instruction *Inst = dyn_cast<Instruction>(U);
- if (!Inst)
- continue;
-
- if (auto *BI = dyn_cast<BitCastInst>(Inst)) {
- traceBitCast(BI, Parent, Kind);
- } else if (auto *CI = dyn_cast<CallInst>(Inst)) {
- uint32_t CIKind;
- if (IsPreserveDIAccessIndexCall(CI, CIKind)) {
- AIChain[CI] = std::make_pair(Parent, Kind);
- traceAICall(CI, CIKind);
- } else {
- BaseAICalls[Parent] = Kind;
- }
- } else if (auto *GI = dyn_cast<GetElementPtrInst>(Inst)) {
- if (GI->hasAllZeroIndices())
- traceGEP(GI, Parent, Kind);
- else
- BaseAICalls[Parent] = Kind;
- }
- }
-}
-
-void BPFAbstractMemberAccess::collectAICallChains(Module &M, Function &F) {
- AIChain.clear();
- BaseAICalls.clear();
-
- for (auto &BB : F)
- for (auto &I : BB) {
- uint32_t Kind;
- auto *Call = dyn_cast<CallInst>(&I);
- if (!IsPreserveDIAccessIndexCall(Call, Kind) ||
- AIChain.find(Call) != AIChain.end())
- continue;
-
- traceAICall(Call, Kind);
- }
-}
-
-/// Get access index from the preserve_*_access_index intrinsic calls.
-bool BPFAbstractMemberAccess::getAccessIndex(const Value *IndexValue,
- uint64_t &AccessIndex) {
- const ConstantInt *CV = dyn_cast<ConstantInt>(IndexValue);
- if (!CV)
- return false;
-
- AccessIndex = CV->getValue().getZExtValue();
- return true;
-}
-
-/// Compute the base of the whole preserve_*_access_index chains, i.e., the base
-/// pointer of the first preserve_*_access_index call, and construct the access
-/// string, which will be the name of a global variable.
-Value *BPFAbstractMemberAccess::computeBaseAndAccessStr(CallInst *Call,
- std::string &AccessStr,
- std::string &AccessKey,
- uint32_t Kind,
- MDNode *&TypeMeta) {
- Value *Base = nullptr;
- std::vector<uint64_t> AccessIndices;
- uint64_t TypeNameIndex = 0;
- std::string LastTypeName;
-
- while (Call) {
- // Base of original corresponding GEP
- Base = Call->getArgOperand(0);
-
- // Type Name
- std::string TypeName;
- MDNode *MDN;
- if (Kind == BPFPreserveUnionAI || Kind == BPFPreserveStructAI) {
- MDN = Call->getMetadata(LLVMContext::MD_preserve_access_index);
- if (!MDN)
- return nullptr;
-
- DIType *Ty = dyn_cast<DIType>(MDN);
- if (!Ty)
- return nullptr;
-
- TypeName = Ty->getName();
- }
-
- // Access Index
- uint64_t AccessIndex;
- uint32_t ArgIndex = (Kind == BPFPreserveUnionAI) ? 1 : 2;
- if (!getAccessIndex(Call->getArgOperand(ArgIndex), AccessIndex))
- return nullptr;
-
- AccessIndices.push_back(AccessIndex);
- if (TypeName.size()) {
- TypeNameIndex = AccessIndices.size() - 1;
- LastTypeName = TypeName;
- TypeMeta = MDN;
- }
-
- Kind = AIChain[Call].second;
- Call = AIChain[Call].first;
- }
-
- // The intial type name is required.
- // FIXME: if the initial type access is an array index, e.g.,
- // &a[3].b.c, only one dimentional array is supported.
- if (!LastTypeName.size() || AccessIndices.size() > TypeNameIndex + 2)
- return nullptr;
-
- // Construct the type string AccessStr.
- for (unsigned I = 0; I < AccessIndices.size(); ++I)
- AccessStr = std::to_string(AccessIndices[I]) + ":" + AccessStr;
-
- if (TypeNameIndex == AccessIndices.size() - 1)
- AccessStr = "0:" + AccessStr;
-
- // Access key is the type name + access string, uniquely identifying
- // one kernel memory access.
- AccessKey = LastTypeName + ":" + AccessStr;
-
- return Base;
-}
-
-/// Call/Kind is the base preserve_*_access_index() call. Attempts to do
-/// transformation to a chain of relocable GEPs.
-bool BPFAbstractMemberAccess::transformGEPChain(Module &M, CallInst *Call,
- uint32_t Kind) {
- std::string AccessStr, AccessKey;
- MDNode *TypeMeta = nullptr;
- Value *Base =
- computeBaseAndAccessStr(Call, AccessStr, AccessKey, Kind, TypeMeta);
- if (!Base)
- return false;
-
- // Do the transformation
- // For any original GEP Call and Base %2 like
- // %4 = bitcast %struct.net_device** %dev1 to i64*
- // it is transformed to:
- // %6 = load __BTF_0:sk_buff:0:0:2:0:
- // %7 = bitcast %struct.sk_buff* %2 to i8*
- // %8 = getelementptr i8, i8* %7, %6
- // %9 = bitcast i8* %8 to i64*
- // using %9 instead of %4
- // The original Call inst is removed.
- BasicBlock *BB = Call->getParent();
- GlobalVariable *GV;
-
- if (GEPGlobals.find(AccessKey) == GEPGlobals.end()) {
- GV = new GlobalVariable(M, Type::getInt64Ty(BB->getContext()), false,
- GlobalVariable::ExternalLinkage, NULL, AccessStr);
- GV->addAttribute(BPFCoreSharedInfo::AmaAttr);
- // Set the metadata (debuginfo types) for the global.
- if (TypeMeta)
- GV->setMetadata(LLVMContext::MD_preserve_access_index, TypeMeta);
- GEPGlobals[AccessKey] = GV;
- } else {
- GV = GEPGlobals[AccessKey];
- }
-
- // Load the global variable.
- auto *LDInst = new LoadInst(Type::getInt64Ty(BB->getContext()), GV);
- BB->getInstList().insert(Call->getIterator(), LDInst);
-
- // Generate a BitCast
- auto *BCInst = new BitCastInst(Base, Type::getInt8PtrTy(BB->getContext()));
- BB->getInstList().insert(Call->getIterator(), BCInst);
-
- // Generate a GetElementPtr
- auto *GEP = GetElementPtrInst::Create(Type::getInt8Ty(BB->getContext()),
- BCInst, LDInst);
- BB->getInstList().insert(Call->getIterator(), GEP);
-
- // Generate a BitCast
- auto *BCInst2 = new BitCastInst(GEP, Call->getType());
- BB->getInstList().insert(Call->getIterator(), BCInst2);
-
- Call->replaceAllUsesWith(BCInst2);
- Call->eraseFromParent();
-
- return true;
-}
-
-bool BPFAbstractMemberAccess::doTransformation(Module &M) {
- bool Transformed = false;
-
- for (Function &F : M) {
- // Collect PreserveDIAccessIndex Intrinsic call chains.
- // The call chains will be used to generate the access
- // patterns similar to GEP.
- collectAICallChains(M, F);
-
- for (auto &C : BaseAICalls)
- Transformed = transformGEPChain(M, C.first, C.second) || Transformed;
- }
-
- return removePreserveAccessIndexIntrinsic(M) || Transformed;
-}
Modified: llvm/trunk/lib/Target/BPF/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/CMakeLists.txt?rev=365532&r1=365531&r2=365532&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/CMakeLists.txt (original)
+++ llvm/trunk/lib/Target/BPF/CMakeLists.txt Tue Jul 9 11:35:46 2019
@@ -13,7 +13,7 @@ tablegen(LLVM BPFGenSubtargetInfo.inc -g
add_public_tablegen_target(BPFCommonTableGen)
add_llvm_target(BPFCodeGen
- BPFAbstrctMemberAccess.cpp
+ BPFAbstractMemberAccess.cpp
BPFAsmPrinter.cpp
BPFFrameLowering.cpp
BPFInstrInfo.cpp
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