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Reland r229944: EH: Prune unreachable resume instructions during Dwarf EH preparation 

Fix the double-deletion of AnalysisResolver when delegating through to
Dwarf EH preparation by creating one from scratch. Hopefully the new
pass manager simplifies this.

This reverts commit r229952.

llvm-svn: 231719
This commit is contained in:
Reid Kleckner 2015-03-09 22:45:16 +00:00
parent 4a8821d48d
commit be0a05060f
9 changed files with 258 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
llvm/include/llvm/CodeGen/Passes.h
View File

@ -612,13 +612,13 @@ namespace llvm {
ModulePass *createForwardControlFlowIntegrityPass();
} // End llvm namespace
/// This initializer registers TargetMachine constructor, so the pass being
/// initialized can use target dependent interfaces. Please do not move this
/// macro to be together with INITIALIZE_PASS, which is a complete target
/// independent initializer, and we don't want to make libScalarOpts depend
/// on libCodeGen.
#define INITIALIZE_TM_PASS(passName, arg, name, cfg, analysis) \
static void* initialize##passName##PassOnce(PassRegistry &Registry) { \
/// Target machine pass initializer for passes with dependencies. Use with
/// INITIALIZE_TM_PASS_END.
#define INITIALIZE_TM_PASS_BEGIN INITIALIZE_PASS_BEGIN
/// Target machine pass initializer for passes with dependencies. Use with
/// INITIALIZE_TM_PASS_BEGIN.
#define INITIALIZE_TM_PASS_END(passName, arg, name, cfg, analysis) \
PassInfo *PI = new PassInfo(name, arg, & passName ::ID, \
PassInfo::NormalCtor_t(callDefaultCtor< passName >), cfg, analysis, \
PassInfo::TargetMachineCtor_t(callTargetMachineCtor< passName >)); \
@ -629,4 +629,13 @@ namespace llvm {
CALL_ONCE_INITIALIZATION(initialize##passName##PassOnce) \
}
/// This initializer registers TargetMachine constructor, so the pass being
/// initialized can use target dependent interfaces. Please do not move this
/// macro to be together with INITIALIZE_PASS, which is a complete target
/// independent initializer, and we don't want to make libScalarOpts depend
/// on libCodeGen.
#define INITIALIZE_TM_PASS(passName, arg, name, cfg, analysis) \
INITIALIZE_TM_PASS_BEGIN(passName, arg, name, cfg, analysis) \
INITIALIZE_TM_PASS_END(passName, arg, name, cfg, analysis)
#endif

20
llvm/lib/CodeGen/CodeGen.cpp
View File

@ -24,9 +24,10 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
initializeBranchFolderPassPass(Registry);
initializeCodeGenPreparePass(Registry);
initializeDeadMachineInstructionElimPass(Registry);
initializeDwarfEHPreparePass(Registry);
initializeEarlyIfConverterPass(Registry);
initializeExpandPostRAPass(Registry);
initializeExpandISelPseudosPass(Registry);
initializeExpandPostRAPass(Registry);
initializeFinalizeMachineBundlesPass(Registry);
initializeGCMachineCodeAnalysisPass(Registry);
initializeGCModuleInfoPass(Registry);
@ -36,31 +37,34 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
initializeLiveStacksPass(Registry);
initializeLiveVariablesPass(Registry);
initializeLocalStackSlotPassPass(Registry);
initializeLowerIntrinsicsPass(Registry);
initializeMachineBlockFrequencyInfoPass(Registry);
initializeMachineBlockPlacementPass(Registry);
initializeMachineBlockPlacementStatsPass(Registry);
initializeMachineCopyPropagationPass(Registry);
initializeMachineCombinerPass(Registry);
initializeMachineCSEPass(Registry);
initializeMachineCombinerPass(Registry);
initializeMachineCopyPropagationPass(Registry);
initializeMachineDominatorTreePass(Registry);
initializeMachinePostDominatorTreePass(Registry);
initializeMachineFunctionPrinterPassPass(Registry);
initializeMachineLICMPass(Registry);
initializeMachineLoopInfoPass(Registry);
initializeMachineModuleInfoPass(Registry);
initializeMachinePostDominatorTreePass(Registry);
initializeMachineSchedulerPass(Registry);
initializeMachineSinkingPass(Registry);
initializeMachineVerifierPassPass(Registry);
initializeOptimizePHIsPass(Registry);
initializePEIPass(Registry);
initializePHIEliminationPass(Registry);
initializePeepholeOptimizerPass(Registry);
initializePostMachineSchedulerPass(Registry);
initializePostRASchedulerPass(Registry);
initializeProcessImplicitDefsPass(Registry);
initializePEIPass(Registry);
initializeRegisterCoalescerPass(Registry);
initializeSlotIndexesPass(Registry);
initializeStackProtectorPass(Registry);
initializeStackColoringPass(Registry);
initializeStackMapLivenessPass(Registry);
initializeStackProtectorPass(Registry);
initializeStackSlotColoringPass(Registry);
initializeTailDuplicatePassPass(Registry);
initializeTargetPassConfigPass(Registry);
@ -70,9 +74,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
initializeUnreachableMachineBlockElimPass(Registry);
initializeVirtRegMapPass(Registry);
initializeVirtRegRewriterPass(Registry);
initializeLowerIntrinsicsPass(Registry);
initializeMachineFunctionPrinterPassPass(Registry);
initializeStackMapLivenessPass(Registry);
initializeWinEHPreparePass(Registry);
}
void LLVMInitializeCodeGen(LLVMPassRegistryRef R) {

98
llvm/lib/CodeGen/DwarfEHPrepare.cpp
View File

@ -13,13 +13,18 @@
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/Passes.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
#define DEBUG_TYPE "dwarfehprepare"
@ -33,18 +38,28 @@ namespace {
// RewindFunction - _Unwind_Resume or the target equivalent.
Constant *RewindFunction;
DominatorTree *DT;
const TargetLowering *TLI;
bool InsertUnwindResumeCalls(Function &Fn);
Value *GetExceptionObject(ResumeInst *RI);
size_t
pruneUnreachableResumes(Function &Fn,
SmallVectorImpl<ResumeInst *> &Resumes,
SmallVectorImpl<LandingPadInst *> &CleanupLPads);
public:
static char ID; // Pass identification, replacement for typeid.
// INITIALIZE_TM_PASS requires a default constructor, but it isn't used in
// practice.
DwarfEHPrepare() : FunctionPass(ID), TM(nullptr), RewindFunction(nullptr) {}
DwarfEHPrepare()
: FunctionPass(ID), TM(nullptr), RewindFunction(nullptr), DT(nullptr),
TLI(nullptr) {}
DwarfEHPrepare(const TargetMachine *TM)
: FunctionPass(ID), TM(TM), RewindFunction(nullptr) {}
: FunctionPass(ID), TM(TM), RewindFunction(nullptr), DT(nullptr),
TLI(nullptr) {}
bool runOnFunction(Function &Fn) override;
@ -53,6 +68,8 @@ namespace {
return false;
}
void getAnalysisUsage(AnalysisUsage &AU) const override;
const char *getPassName() const override {
return "Exception handling preparation";
}
@ -60,13 +77,22 @@ namespace {
} // end anonymous namespace
char DwarfEHPrepare::ID = 0;
INITIALIZE_TM_PASS(DwarfEHPrepare, "dwarfehprepare", "Prepare DWARF exceptions",
false, false)
INITIALIZE_TM_PASS_BEGIN(DwarfEHPrepare, "dwarfehprepare",
"Prepare DWARF exceptions", false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
INITIALIZE_TM_PASS_END(DwarfEHPrepare, "dwarfehprepare",
"Prepare DWARF exceptions", false, false)
FunctionPass *llvm::createDwarfEHPass(const TargetMachine *TM) {
return new DwarfEHPrepare(TM);
}
void DwarfEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetTransformInfoWrapperPass>();
AU.addRequired<DominatorTreeWrapperPass>();
}
/// GetExceptionObject - Return the exception object from the value passed into
/// the 'resume' instruction (typically an aggregate). Clean up any dead
/// instructions, including the 'resume' instruction.
@ -107,21 +133,71 @@ Value *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {
return ExnObj;
}
/// Replace resumes that are not reachable from a cleanup landing pad with
/// unreachable and then simplify those blocks.
size_t DwarfEHPrepare::pruneUnreachableResumes(
Function &Fn, SmallVectorImpl<ResumeInst *> &Resumes,
SmallVectorImpl<LandingPadInst *> &CleanupLPads) {
BitVector ResumeReachable(Resumes.size());
size_t ResumeIndex = 0;
for (auto *RI : Resumes) {
for (auto *LP : CleanupLPads) {
if (isPotentiallyReachable(LP, RI, DT)) {
ResumeReachable.set(ResumeIndex);
break;
}
}
++ResumeIndex;
}
// If everything is reachable, there is no change.
if (ResumeReachable.all())
return Resumes.size();
const TargetTransformInfo &TTI =
getAnalysis<TargetTransformInfoWrapperPass>().getTTI(Fn);
LLVMContext &Ctx = Fn.getContext();
// Otherwise, insert unreachable instructions and call simplifycfg.
size_t ResumesLeft = 0;
for (size_t I = 0, E = Resumes.size(); I < E; ++I) {
ResumeInst *RI = Resumes[I];
if (ResumeReachable[I]) {
Resumes[ResumesLeft++] = RI;
} else {
BasicBlock *BB = RI->getParent();
new UnreachableInst(Ctx, RI);
RI->eraseFromParent();
SimplifyCFG(BB, TTI, 1, TLI->getDataLayout());
}
}
Resumes.resize(ResumesLeft);
return ResumesLeft;
}
/// InsertUnwindResumeCalls - Convert the ResumeInsts that are still present
/// into calls to the appropriate _Unwind_Resume function.
bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
SmallVector<ResumeInst*, 16> Resumes;
SmallVector<LandingPadInst*, 16> CleanupLPads;
for (BasicBlock &BB : Fn) {
if (auto *RI = dyn_cast<ResumeInst>(BB.getTerminator()))
Resumes.push_back(RI);
if (auto *LP = BB.getLandingPadInst())
if (LP->isCleanup())
CleanupLPads.push_back(LP);
}
if (Resumes.empty())
return false;
// Find the rewind function if we didn't already.
const TargetLowering *TLI = TM->getSubtargetImpl(Fn)->getTargetLowering();
LLVMContext &Ctx = Fn.getContext();
size_t ResumesLeft = pruneUnreachableResumes(Fn, Resumes, CleanupLPads);
if (ResumesLeft == 0)
return true; // We pruned them all.
// Find the rewind function if we didn't already.
if (!RewindFunction) {
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx),
Type::getInt8PtrTy(Ctx), false);
@ -130,9 +206,7 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
}
// Create the basic block where the _Unwind_Resume call will live.
unsigned ResumesSize = Resumes.size();
if (ResumesSize == 1) {
if (ResumesLeft == 1) {
// Instead of creating a new BB and PHI node, just append the call to
// _Unwind_Resume to the end of the single resume block.
ResumeInst *RI = Resumes.front();
@ -149,7 +223,7 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
}
BasicBlock *UnwindBB = BasicBlock::Create(Ctx, "unwind_resume", &Fn);
PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), ResumesSize,
PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), ResumesLeft,
"exn.obj", UnwindBB);
// Extract the exception object from the ResumeInst and add it to the PHI node
@ -175,6 +249,10 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
bool DwarfEHPrepare::runOnFunction(Function &Fn) {
assert(TM && "DWARF EH preparation requires a target machine");
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
TLI = TM->getSubtargetImpl(Fn)->getTargetLowering();
bool Changed = InsertUnwindResumeCalls(Fn);
DT = nullptr;
TLI = nullptr;
return Changed;
}

28
llvm/lib/CodeGen/WinEHPrepare.cpp
View File

@ -18,6 +18,8 @@
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/Analysis/LibCallSemantics.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
@ -168,8 +170,13 @@ public:
} // end anonymous namespace
char WinEHPrepare::ID = 0;
INITIALIZE_TM_PASS(WinEHPrepare, "winehprepare", "Prepare Windows exceptions",
false, false)
INITIALIZE_TM_PASS_BEGIN(WinEHPrepare, "winehprepare",
"Prepare Windows exceptions", false, false)
INITIALIZE_PASS_DEPENDENCY(DwarfEHPrepare)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
INITIALIZE_TM_PASS_END(WinEHPrepare, "winehprepare",
"Prepare Windows exceptions", false, false)
FunctionPass *llvm::createWinEHPass(const TargetMachine *TM) {
return new WinEHPrepare(TM);
@ -198,8 +205,23 @@ bool WinEHPrepare::runOnFunction(Function &Fn) {
EHPersonality Pers = classifyEHPersonality(LPads.back()->getPersonalityFn());
// Delegate through to the DWARF pass if this is unrecognized.
if (!isMSVCPersonality(Pers))
if (!isMSVCPersonality(Pers)) {
if (!DwarfPrepare->getResolver()) {
// Build an AnalysisResolver with the analyses needed by DwarfEHPrepare.
// It will take ownership of the AnalysisResolver.
assert(getResolver());
auto *AR = new AnalysisResolver(getResolver()->getPMDataManager());
AR->addAnalysisImplsPair(
&TargetTransformInfoWrapperPass::ID,
getResolver()->findImplPass(&TargetTransformInfoWrapperPass::ID));
AR->addAnalysisImplsPair(
&DominatorTreeWrapperPass::ID,
getResolver()->findImplPass(&DominatorTreeWrapperPass::ID));
DwarfPrepare->setResolver(AR);
}
return DwarfPrepare->runOnFunction(Fn);
}
// FIXME: This only returns true if the C++ EH handlers were outlined.
// When that code is complete, it should always return whatever

1
llvm/test/CodeGen/Mips/eh.ll
View File

@ -27,6 +27,7 @@ lpad: ; preds = %entry
; CHECK-EL: bne $5
%exn.val = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
cleanup
catch i8* bitcast (i8** @_ZTId to i8*)
%exn = extractvalue { i8*, i32 } %exn.val, 0
%sel = extractvalue { i8*, i32 } %exn.val, 1

115
llvm/test/CodeGen/X86/dwarf-eh-prepare.ll
View File

@ -7,12 +7,13 @@
@int_typeinfo = global i8 0
declare void @might_throw()
declare void @cleanup()
define i32 @simple_catch() {
define i32 @simple_cleanup_catch() {
invoke void @might_throw()
to label %cont unwind label %lpad
; CHECK: define i32 @simple_catch()
; CHECK-LABEL: define i32 @simple_cleanup_catch()
; CHECK: invoke void @might_throw()
cont:
@ -22,15 +23,18 @@ cont:
lpad:
%ehvals = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
cleanup
catch i8* @int_typeinfo
%ehptr = extractvalue { i8*, i32 } %ehvals, 0
%ehsel = extractvalue { i8*, i32 } %ehvals, 1
call void @cleanup()
%int_sel = call i32 @llvm.eh.typeid.for(i8* @int_typeinfo)
%int_match = icmp eq i32 %ehsel, %int_sel
br i1 %int_match, label %catch_int, label %eh.resume
; CHECK: lpad:
; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
; CHECK: call void @cleanup()
; CHECK: call i32 @llvm.eh.typeid.for
; CHECK: br i1
@ -41,11 +45,114 @@ catch_int:
; CHECK: ret i32 1
eh.resume:
resume { i8*, i32 } %ehvals
%tmp_ehvals = insertvalue { i8*, i32 } undef, i8* %ehptr, 0
%new_ehvals = insertvalue { i8*, i32 } %tmp_ehvals, i32 %ehsel, 1
resume { i8*, i32 } %new_ehvals
; CHECK: eh.resume:
; CHECK: call void @_Unwind_Resume(i8* %{{.*}})
; CHECK-NEXT: call void @_Unwind_Resume(i8* %ehptr)
}
define i32 @catch_no_resume() {
invoke void @might_throw()
to label %cont unwind label %lpad
cont:
ret i32 0
lpad:
%ehvals = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
catch i8* @int_typeinfo
%ehptr = extractvalue { i8*, i32 } %ehvals, 0
%ehsel = extractvalue { i8*, i32 } %ehvals, 1
%int_sel = call i32 @llvm.eh.typeid.for(i8* @int_typeinfo)
%int_match = icmp eq i32 %ehsel, %int_sel
br i1 %int_match, label %catch_int, label %eh.resume
catch_int:
ret i32 1
eh.resume:
%tmp_ehvals = insertvalue { i8*, i32 } undef, i8* %ehptr, 0
%new_ehvals = insertvalue { i8*, i32 } %tmp_ehvals, i32 %ehsel, 1
resume { i8*, i32 } %new_ehvals
}
; Check that we can prune the unreachable resume instruction.
; CHECK-LABEL: define i32 @catch_no_resume() {
; CHECK: invoke void @might_throw()
; CHECK: ret i32 0
; CHECK: lpad:
; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
; CHECK-NOT: br i1
; CHECK: ret i32 1
; CHECK-NOT: call void @_Unwind_Resume
; CHECK: {{^[}]}}
define i32 @catch_cleanup_merge() {
invoke void @might_throw()
to label %inner_invoke unwind label %outer_lpad
inner_invoke:
invoke void @might_throw()
to label %cont unwind label %inner_lpad
cont:
ret i32 0
outer_lpad:
%ehvals1 = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
catch i8* @int_typeinfo
br label %catch.dispatch
inner_lpad:
%ehvals2 = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
cleanup
catch i8* @int_typeinfo
call void @cleanup()
br label %catch.dispatch
catch.dispatch:
%ehvals = phi { i8*, i32 } [ %ehvals1, %outer_lpad ], [ %ehvals2, %inner_lpad ]
%ehptr = extractvalue { i8*, i32 } %ehvals, 0
%ehsel = extractvalue { i8*, i32 } %ehvals, 1
%int_sel = call i32 @llvm.eh.typeid.for(i8* @int_typeinfo)
%int_match = icmp eq i32 %ehsel, %int_sel
br i1 %int_match, label %catch_int, label %eh.resume
catch_int:
ret i32 1
eh.resume:
%tmp_ehvals = insertvalue { i8*, i32 } undef, i8* %ehptr, 0
%new_ehvals = insertvalue { i8*, i32 } %tmp_ehvals, i32 %ehsel, 1
resume { i8*, i32 } %new_ehvals
}
; We can't prune this merge because one landingpad is a cleanup pad.
; CHECK-LABEL: define i32 @catch_cleanup_merge()
; CHECK: invoke void @might_throw()
; CHECK: invoke void @might_throw()
; CHECK: ret i32 0
;
; CHECK: outer_lpad:
; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
; CHECK: br label %catch.dispatch
;
; CHECK: inner_lpad:
; CHECK: landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
; CHECK: call void @cleanup()
; CHECK: br label %catch.dispatch
;
; CHECK: catch.dispatch:
; CHECK: call i32 @llvm.eh.typeid.for
; CHECK: br i1
; CHECK: catch_int:
; CHECK: ret i32 1
; CHECK: eh.resume:
; CHECK-NEXT: call void @_Unwind_Resume(i8* %ehptr)
declare i32 @__gxx_personality_v0(...)
declare i32 @llvm.eh.typeid.for(i8*)

1
llvm/test/CodeGen/X86/gcc_except_table.ll
View File

@ -37,6 +37,7 @@ entry:
lpad:
%0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
cleanup
catch i8* bitcast (i8** @_ZTIi to i8*)
br label %eh.resume

1
llvm/test/CodeGen/X86/gcc_except_table_functions.ll
View File

@ -20,6 +20,7 @@ try.cont:
lpad:
%0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
cleanup
catch i8* bitcast (void ()* @filt0 to i8*)
catch i8* bitcast (void ()* @filt1 to i8*)
%sel = extractvalue { i8*, i32 } %0, 1

6
llvm/test/CodeGen/XCore/exception.ll
View File

@ -78,6 +78,7 @@ cont:
; CHECK: bl __cxa_end_catch
lpad:
%0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
cleanup
catch i8* bitcast (i8** @_ZTIi to i8*)
catch i8* bitcast (i8** @_ZTId to i8*)
%1 = extractvalue { i8*, i32 } %0, 0
@ -110,13 +111,14 @@ Exit:
; CHECK: .long [[PRE_G]]-[[START]]
; CHECK: .long [[POST_G]]-[[PRE_G]]
; CHECK: .long [[LANDING]]-[[START]]
; CHECK: .byte 3
; CHECK: .byte 5
; CHECK: .long [[POST_G]]-[[START]]
; CHECK: .long [[END]]-[[POST_G]]
; CHECK: .long 0
; CHECK: .byte 0
; CHECK: .byte 1
; CHECK: .byte 0
; CHECK: .byte 1
; CHECK: .byte 125
; CHECK: .byte 2
; CHECK: .byte 125
; CHECK: .long _ZTIi