[llvm] r204388 - Remove LowerInvoke's obsolete "-enable-correct-eh-support" option
Mark Seaborn
mseaborn at chromium.org
Thu Mar 20 12:54:48 PDT 2014
Author: mseaborn
Date: Thu Mar 20 14:54:47 2014
New Revision: 204388
URL: http://llvm.org/viewvc/llvm-project?rev=204388&view=rev
Log:
Remove LowerInvoke's obsolete "-enable-correct-eh-support" option
This option caused LowerInvoke to generate code using SJLJ-based
exception handling, but there is no code left that interprets the
jmp_buf stack that the resulting code maintained (llvm.sjljeh.jblist).
This option has been obsolete for a while, and replaced by
SjLjEHPrepare.
This leaves the default behaviour of LowerInvoke, which is to convert
invokes to calls.
Differential Revision: http://llvm-reviews.chandlerc.com/D3136
Removed:
llvm/trunk/test/Transforms/LowerInvoke/2004-02-29-PHICrash.ll
llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHI.ll
llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHIUse.ll
llvm/trunk/test/Transforms/LowerInvoke/2008-02-14-CritEdgePhiCrash.ll
llvm/trunk/test/Transforms/LowerInvoke/basictest.ll
Modified:
llvm/trunk/docs/CommandGuide/llc.rst
llvm/trunk/docs/CommandGuide/lli.rst
llvm/trunk/docs/Passes.rst
llvm/trunk/include/llvm/Transforms/Scalar.h
llvm/trunk/lib/CodeGen/Passes.cpp
llvm/trunk/lib/Transforms/Utils/LowerInvoke.cpp
Modified: llvm/trunk/docs/CommandGuide/llc.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/CommandGuide/llc.rst?rev=204388&r1=204387&r2=204388&view=diff
==============================================================================
--- llvm/trunk/docs/CommandGuide/llc.rst (original)
+++ llvm/trunk/docs/CommandGuide/llc.rst Thu Mar 20 14:54:47 2014
@@ -112,11 +112,6 @@ End-user Options
optimizations allow the code generator to make use of some instructions which
would otherwise not be usable (such as ``fsin`` on X86).
-.. option:: --enable-correct-eh-support
-
- Instruct the **lowerinvoke** pass to insert code for correct exception
- handling support. This is expensive and is by default omitted for efficiency.
-
.. option:: --stats
Print statistics recorded by code-generation passes.
Modified: llvm/trunk/docs/CommandGuide/lli.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/CommandGuide/lli.rst?rev=204388&r1=204387&r2=204388&view=diff
==============================================================================
--- llvm/trunk/docs/CommandGuide/lli.rst (original)
+++ llvm/trunk/docs/CommandGuide/lli.rst Thu Mar 20 14:54:47 2014
@@ -190,12 +190,6 @@ CODE GENERATION OPTIONS
-**-enable-correct-eh-support**
-
- Make the -lowerinvoke pass insert expensive, but correct, EH code.
-
-
-
**-jit-enable-eh**
Exception handling should be enabled in the just-in-time compiler.
Modified: llvm/trunk/docs/Passes.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/Passes.rst?rev=204388&r1=204387&r2=204388&view=diff
==============================================================================
--- llvm/trunk/docs/Passes.rst (original)
+++ llvm/trunk/docs/Passes.rst Thu Mar 20 14:54:47 2014
@@ -893,33 +893,14 @@ this would require knowledge of the enti
any libraries which may not be available in bitcode form); it simply lowers
every atomic intrinsic.
-``-lowerinvoke``: Lower invoke and unwind, for unwindless code generators
--------------------------------------------------------------------------
+``-lowerinvoke``: Lower invokes to calls, for unwindless code generators
+------------------------------------------------------------------------
This transformation is designed for use by code generators which do not yet
-support stack unwinding. This pass supports two models of exception handling
-lowering, the "cheap" support and the "expensive" support.
-
-"Cheap" exception handling support gives the program the ability to execute any
-program which does not "throw an exception", by turning "``invoke``"
-instructions into calls and by turning "``unwind``" instructions into calls to
-``abort()``. If the program does dynamically use the "``unwind``" instruction,
-the program will print a message then abort.
-
-"Expensive" exception handling support gives the full exception handling
-support to the program at the cost of making the "``invoke``" instruction
-really expensive. It basically inserts ``setjmp``/``longjmp`` calls to emulate
-the exception handling as necessary.
-
-Because the "expensive" support slows down programs a lot, and EH is only used
-for a subset of the programs, it must be specifically enabled by the
-``-enable-correct-eh-support`` option.
-
-Note that after this pass runs the CFG is not entirely accurate (exceptional
-control flow edges are not correct anymore) so only very simple things should
-be done after the ``lowerinvoke`` pass has run (like generation of native
-code). This should not be used as a general purpose "my LLVM-to-LLVM pass
-doesn't support the ``invoke`` instruction yet" lowering pass.
+support stack unwinding. This pass converts ``invoke`` instructions to
+``call`` instructions, so that any exception-handling ``landingpad`` blocks
+become dead code (which can be removed by running the ``-simplifycfg`` pass
+afterwards).
``-lowerswitch``: Lower ``SwitchInst``\ s to branches
-----------------------------------------------------
Modified: llvm/trunk/include/llvm/Transforms/Scalar.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar.h?rev=204388&r1=204387&r2=204388&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Scalar.h (original)
+++ llvm/trunk/include/llvm/Transforms/Scalar.h Thu Mar 20 14:54:47 2014
@@ -262,16 +262,10 @@ extern char &LowerSwitchID;
//===----------------------------------------------------------------------===//
//
-// LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
-// exception handling mechanisms. Note that after this pass runs the CFG is not
-// entirely accurate (exceptional control flow edges are not correct anymore) so
-// only very simple things should be done after the lowerinvoke pass has run
-// (like generation of native code). This should *NOT* be used as a general
-// purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
-// lowering pass.
+// LowerInvoke - This pass removes invoke instructions, converting them to call
+// instructions.
//
-FunctionPass *createLowerInvokePass(const TargetMachine *TM = 0,
- bool useExpensiveEHSupport = false);
+FunctionPass *createLowerInvokePass();
extern char &LowerInvokePassID;
//===----------------------------------------------------------------------===//
Modified: llvm/trunk/lib/CodeGen/Passes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/Passes.cpp?rev=204388&r1=204387&r2=204388&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/Passes.cpp (original)
+++ llvm/trunk/lib/CodeGen/Passes.cpp Thu Mar 20 14:54:47 2014
@@ -423,7 +423,7 @@ void TargetPassConfig::addPassesToHandle
addPass(createDwarfEHPass(TM));
break;
case ExceptionHandling::None:
- addPass(createLowerInvokePass(TM));
+ addPass(createLowerInvokePass());
// The lower invoke pass may create unreachable code. Remove it.
addPass(createUnreachableBlockEliminationPass());
Modified: llvm/trunk/lib/Transforms/Utils/LowerInvoke.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LowerInvoke.cpp?rev=204388&r1=204387&r2=204388&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LowerInvoke.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LowerInvoke.cpp Thu Mar 20 14:54:47 2014
@@ -1,4 +1,4 @@
-//===- LowerInvoke.cpp - Eliminate Invoke & Unwind instructions -----------===//
+//===- LowerInvoke.cpp - Eliminate Invoke instructions --------------------===//
//
// The LLVM Compiler Infrastructure
//
@@ -8,29 +8,9 @@
//===----------------------------------------------------------------------===//
//
// This transformation is designed for use by code generators which do not yet
-// support stack unwinding. This pass supports two models of exception handling
-// lowering, the 'cheap' support and the 'expensive' support.
-//
-// 'Cheap' exception handling support gives the program the ability to execute
-// any program which does not "throw an exception", by turning 'invoke'
-// instructions into calls and by turning 'unwind' instructions into calls to
-// abort(). If the program does dynamically use the unwind instruction, the
-// program will print a message then abort.
-//
-// 'Expensive' exception handling support gives the full exception handling
-// support to the program at the cost of making the 'invoke' instruction
-// really expensive. It basically inserts setjmp/longjmp calls to emulate the
-// exception handling as necessary.
-//
-// Because the 'expensive' support slows down programs a lot, and EH is only
-// used for a subset of the programs, it must be specifically enabled by an
-// option.
-//
-// Note that after this pass runs the CFG is not entirely accurate (exceptional
-// control flow edges are not correct anymore) so only very simple things should
-// be done after the lowerinvoke pass has run (like generation of native code).
-// This should not be used as a general purpose "my LLVM-to-LLVM pass doesn't
-// support the invoke instruction yet" lowering pass.
+// support stack unwinding. This pass converts 'invoke' instructions to 'call'
+// instructions, so that any exception-handling 'landingpad' blocks become dead
+// code (which can be removed by running the '-simplifycfg' pass afterwards).
//
//===----------------------------------------------------------------------===//
@@ -38,64 +18,23 @@
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
-#include "llvm/Target/TargetLowering.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include <csetjmp>
-#include <set>
using namespace llvm;
STATISTIC(NumInvokes, "Number of invokes replaced");
-STATISTIC(NumSpilled, "Number of registers live across unwind edges");
-
-static cl::opt<bool> ExpensiveEHSupport("enable-correct-eh-support",
- cl::desc("Make the -lowerinvoke pass insert expensive, but correct, EH code"));
namespace {
class LowerInvoke : public FunctionPass {
- const TargetMachine *TM;
-
- // Used for both models.
- Constant *AbortFn;
-
- // Used for expensive EH support.
- StructType *JBLinkTy;
- GlobalVariable *JBListHead;
- Constant *SetJmpFn, *LongJmpFn, *StackSaveFn, *StackRestoreFn;
- bool useExpensiveEHSupport;
-
public:
static char ID; // Pass identification, replacement for typeid
- explicit LowerInvoke(const TargetMachine *TM = 0,
- bool useExpensiveEHSupport = ExpensiveEHSupport)
- : FunctionPass(ID), TM(TM),
- useExpensiveEHSupport(useExpensiveEHSupport) {
+ explicit LowerInvoke() : FunctionPass(ID) {
initializeLowerInvokePass(*PassRegistry::getPassRegistry());
}
- bool doInitialization(Module &M) override;
bool runOnFunction(Function &F) override;
-
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- // This is a cluster of orthogonal Transforms
- AU.addPreserved("mem2reg");
- AU.addPreservedID(LowerSwitchID);
- }
-
- private:
- bool insertCheapEHSupport(Function &F);
- void splitLiveRangesLiveAcrossInvokes(SmallVectorImpl<InvokeInst*>&Invokes);
- void rewriteExpensiveInvoke(InvokeInst *II, unsigned InvokeNo,
- AllocaInst *InvokeNum, AllocaInst *StackPtr,
- SwitchInst *CatchSwitch);
- bool insertExpensiveEHSupport(Function &F);
};
}
@@ -107,65 +46,11 @@ INITIALIZE_PASS(LowerInvoke, "lowerinvok
char &llvm::LowerInvokePassID = LowerInvoke::ID;
// Public Interface To the LowerInvoke pass.
-FunctionPass *llvm::createLowerInvokePass(const TargetMachine *TM,
- bool useExpensiveEHSupport) {
- return new LowerInvoke(TM, useExpensiveEHSupport || ExpensiveEHSupport);
+FunctionPass *llvm::createLowerInvokePass() {
+ return new LowerInvoke();
}
-// doInitialization - Make sure that there is a prototype for abort in the
-// current module.
-bool LowerInvoke::doInitialization(Module &M) {
- Type *VoidPtrTy = Type::getInt8PtrTy(M.getContext());
- if (useExpensiveEHSupport) {
- // Insert a type for the linked list of jump buffers.
- const TargetLowering *TLI = TM ? TM->getTargetLowering() : 0;
- unsigned JBSize = TLI ? TLI->getJumpBufSize() : 0;
- JBSize = JBSize ? JBSize : 200;
- Type *JmpBufTy = ArrayType::get(VoidPtrTy, JBSize);
-
- JBLinkTy = StructType::create(M.getContext(), "llvm.sjljeh.jmpbufty");
- Type *Elts[] = { JmpBufTy, PointerType::getUnqual(JBLinkTy) };
- JBLinkTy->setBody(Elts);
-
- Type *PtrJBList = PointerType::getUnqual(JBLinkTy);
-
- // Now that we've done that, insert the jmpbuf list head global, unless it
- // already exists.
- if (!(JBListHead = M.getGlobalVariable("llvm.sjljeh.jblist", PtrJBList))) {
- JBListHead = new GlobalVariable(M, PtrJBList, false,
- GlobalValue::LinkOnceAnyLinkage,
- Constant::getNullValue(PtrJBList),
- "llvm.sjljeh.jblist");
- }
-
-// VisualStudio defines setjmp as _setjmp
-#if defined(_MSC_VER) && defined(setjmp) && \
- !defined(setjmp_undefined_for_msvc)
-# pragma push_macro("setjmp")
-# undef setjmp
-# define setjmp_undefined_for_msvc
-#endif
-
- SetJmpFn = Intrinsic::getDeclaration(&M, Intrinsic::setjmp);
-
-#if defined(_MSC_VER) && defined(setjmp_undefined_for_msvc)
- // let's return it to _setjmp state
-# pragma pop_macro("setjmp")
-# undef setjmp_undefined_for_msvc
-#endif
-
- LongJmpFn = Intrinsic::getDeclaration(&M, Intrinsic::longjmp);
- StackSaveFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
- StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
- }
-
- // We need the 'write' and 'abort' functions for both models.
- AbortFn = M.getOrInsertFunction("abort", Type::getVoidTy(M.getContext()),
- (Type *)0);
- return true;
-}
-
-bool LowerInvoke::insertCheapEHSupport(Function &F) {
+bool LowerInvoke::runOnFunction(Function &F) {
bool Changed = false;
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
@@ -192,387 +77,3 @@ bool LowerInvoke::insertCheapEHSupport(F
}
return Changed;
}
-
-/// rewriteExpensiveInvoke - Insert code and hack the function to replace the
-/// specified invoke instruction with a call.
-void LowerInvoke::rewriteExpensiveInvoke(InvokeInst *II, unsigned InvokeNo,
- AllocaInst *InvokeNum,
- AllocaInst *StackPtr,
- SwitchInst *CatchSwitch) {
- ConstantInt *InvokeNoC = ConstantInt::get(Type::getInt32Ty(II->getContext()),
- InvokeNo);
-
- // If the unwind edge has phi nodes, split the edge.
- if (isa<PHINode>(II->getUnwindDest()->begin())) {
- SplitCriticalEdge(II, 1, this);
-
- // If there are any phi nodes left, they must have a single predecessor.
- while (PHINode *PN = dyn_cast<PHINode>(II->getUnwindDest()->begin())) {
- PN->replaceAllUsesWith(PN->getIncomingValue(0));
- PN->eraseFromParent();
- }
- }
-
- // Insert a store of the invoke num before the invoke and store zero into the
- // location afterward.
- new StoreInst(InvokeNoC, InvokeNum, true, II); // volatile
-
- // Insert a store of the stack ptr before the invoke, so we can restore it
- // later in the exception case.
- CallInst* StackSaveRet = CallInst::Create(StackSaveFn, "ssret", II);
- new StoreInst(StackSaveRet, StackPtr, true, II); // volatile
-
- BasicBlock::iterator NI = II->getNormalDest()->getFirstInsertionPt();
- // nonvolatile.
- new StoreInst(Constant::getNullValue(Type::getInt32Ty(II->getContext())),
- InvokeNum, false, NI);
-
- Instruction* StackPtrLoad =
- new LoadInst(StackPtr, "stackptr.restore", true,
- II->getUnwindDest()->getFirstInsertionPt());
- CallInst::Create(StackRestoreFn, StackPtrLoad, "")->insertAfter(StackPtrLoad);
-
- // Add a switch case to our unwind block.
- CatchSwitch->addCase(InvokeNoC, II->getUnwindDest());
-
- // Insert a normal call instruction.
- SmallVector<Value*,16> CallArgs(II->op_begin(), II->op_end() - 3);
- CallInst *NewCall = CallInst::Create(II->getCalledValue(),
- CallArgs, "", II);
- NewCall->takeName(II);
- NewCall->setCallingConv(II->getCallingConv());
- NewCall->setAttributes(II->getAttributes());
- NewCall->setDebugLoc(II->getDebugLoc());
- II->replaceAllUsesWith(NewCall);
-
- // Replace the invoke with an uncond branch.
- BranchInst::Create(II->getNormalDest(), NewCall->getParent());
- II->eraseFromParent();
-}
-
-/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until
-/// we reach blocks we've already seen.
-static void MarkBlocksLiveIn(BasicBlock *BB, std::set<BasicBlock*> &LiveBBs) {
- if (!LiveBBs.insert(BB).second) return; // already been here.
-
- for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
- MarkBlocksLiveIn(*PI, LiveBBs);
-}
-
-// First thing we need to do is scan the whole function for values that are
-// live across unwind edges. Each value that is live across an unwind edge
-// we spill into a stack location, guaranteeing that there is nothing live
-// across the unwind edge. This process also splits all critical edges
-// coming out of invoke's.
-void LowerInvoke::
-splitLiveRangesLiveAcrossInvokes(SmallVectorImpl<InvokeInst*> &Invokes) {
- // First step, split all critical edges from invoke instructions.
- for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
- InvokeInst *II = Invokes[i];
- SplitCriticalEdge(II, 0, this);
- SplitCriticalEdge(II, 1, this);
- assert(!isa<PHINode>(II->getNormalDest()) &&
- !isa<PHINode>(II->getUnwindDest()) &&
- "critical edge splitting left single entry phi nodes?");
- }
-
- Function *F = Invokes.back()->getParent()->getParent();
-
- // To avoid having to handle incoming arguments specially, we lower each arg
- // to a copy instruction in the entry block. This ensures that the argument
- // value itself cannot be live across the entry block.
- BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin();
- while (isa<AllocaInst>(AfterAllocaInsertPt) &&
- isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize()))
- ++AfterAllocaInsertPt;
- for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
- AI != E; ++AI) {
- Type *Ty = AI->getType();
- // Aggregate types can't be cast, but are legal argument types, so we have
- // to handle them differently. We use an extract/insert pair as a
- // lightweight method to achieve the same goal.
- if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
- Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt);
- Instruction *NI = InsertValueInst::Create(AI, EI, 0);
- NI->insertAfter(EI);
- AI->replaceAllUsesWith(NI);
- // Set the operand of the instructions back to the AllocaInst.
- EI->setOperand(0, AI);
- NI->setOperand(0, AI);
- } else {
- // This is always a no-op cast because we're casting AI to AI->getType()
- // so src and destination types are identical. BitCast is the only
- // possibility.
- CastInst *NC = new BitCastInst(
- AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt);
- AI->replaceAllUsesWith(NC);
- // Set the operand of the cast instruction back to the AllocaInst.
- // Normally it's forbidden to replace a CastInst's operand because it
- // could cause the opcode to reflect an illegal conversion. However,
- // we're replacing it here with the same value it was constructed with.
- // We do this because the above replaceAllUsesWith() clobbered the
- // operand, but we want this one to remain.
- NC->setOperand(0, AI);
- }
- }
-
- // Finally, scan the code looking for instructions with bad live ranges.
- for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
- for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) {
- // Ignore obvious cases we don't have to handle. In particular, most
- // instructions either have no uses or only have a single use inside the
- // current block. Ignore them quickly.
- Instruction *Inst = II;
- if (Inst->use_empty()) continue;
- if (Inst->hasOneUse() &&
- cast<Instruction>(Inst->user_back())->getParent() == BB &&
- !isa<PHINode>(Inst->user_back())) continue;
-
- // If this is an alloca in the entry block, it's not a real register
- // value.
- if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
- if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin())
- continue;
-
- // Avoid iterator invalidation by copying users to a temporary vector.
- SmallVector<Instruction*,16> Users;
- for (User *U : Inst->users()) {
- Instruction *UI = cast<Instruction>(U);
- if (UI->getParent() != BB || isa<PHINode>(UI))
- Users.push_back(UI);
- }
-
- // Scan all of the uses and see if the live range is live across an unwind
- // edge. If we find a use live across an invoke edge, create an alloca
- // and spill the value.
-
- // Find all of the blocks that this value is live in.
- std::set<BasicBlock*> LiveBBs;
- LiveBBs.insert(Inst->getParent());
- while (!Users.empty()) {
- Instruction *U = Users.back();
- Users.pop_back();
-
- if (!isa<PHINode>(U)) {
- MarkBlocksLiveIn(U->getParent(), LiveBBs);
- } else {
- // Uses for a PHI node occur in their predecessor block.
- PHINode *PN = cast<PHINode>(U);
- for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- if (PN->getIncomingValue(i) == Inst)
- MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
- }
- }
-
- // Now that we know all of the blocks that this thing is live in, see if
- // it includes any of the unwind locations.
- bool NeedsSpill = false;
- for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
- BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
- if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
- NeedsSpill = true;
- }
- }
-
- // If we decided we need a spill, do it.
- if (NeedsSpill) {
- ++NumSpilled;
- DemoteRegToStack(*Inst, true);
- }
- }
-}
-
-bool LowerInvoke::insertExpensiveEHSupport(Function &F) {
- SmallVector<ReturnInst*,16> Returns;
- SmallVector<InvokeInst*,16> Invokes;
- UnreachableInst* UnreachablePlaceholder = 0;
-
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
- if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
- // Remember all return instructions in case we insert an invoke into this
- // function.
- Returns.push_back(RI);
- } else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
- Invokes.push_back(II);
- }
-
- if (Invokes.empty()) return false;
-
- NumInvokes += Invokes.size();
-
- // TODO: This is not an optimal way to do this. In particular, this always
- // inserts setjmp calls into the entries of functions with invoke instructions
- // even though there are possibly paths through the function that do not
- // execute any invokes. In particular, for functions with early exits, e.g.
- // the 'addMove' method in hexxagon, it would be nice to not have to do the
- // setjmp stuff on the early exit path. This requires a bit of dataflow, but
- // would not be too hard to do.
-
- // If we have an invoke instruction, insert a setjmp that dominates all
- // invokes. After the setjmp, use a cond branch that goes to the original
- // code path on zero, and to a designated 'catch' block of nonzero.
- Value *OldJmpBufPtr = 0;
- if (!Invokes.empty()) {
- // First thing we need to do is scan the whole function for values that are
- // live across unwind edges. Each value that is live across an unwind edge
- // we spill into a stack location, guaranteeing that there is nothing live
- // across the unwind edge. This process also splits all critical edges
- // coming out of invoke's.
- splitLiveRangesLiveAcrossInvokes(Invokes);
-
- BasicBlock *EntryBB = F.begin();
-
- // Create an alloca for the incoming jump buffer ptr and the new jump buffer
- // that needs to be restored on all exits from the function. This is an
- // alloca because the value needs to be live across invokes.
- const TargetLowering *TLI = TM ? TM->getTargetLowering() : 0;
- unsigned Align = TLI ? TLI->getJumpBufAlignment() : 0;
- AllocaInst *JmpBuf =
- new AllocaInst(JBLinkTy, 0, Align,
- "jblink", F.begin()->begin());
-
- Value *Idx[] = { Constant::getNullValue(Type::getInt32Ty(F.getContext())),
- ConstantInt::get(Type::getInt32Ty(F.getContext()), 1) };
- OldJmpBufPtr = GetElementPtrInst::Create(JmpBuf, Idx, "OldBuf",
- EntryBB->getTerminator());
-
- // Copy the JBListHead to the alloca.
- Value *OldBuf = new LoadInst(JBListHead, "oldjmpbufptr", true,
- EntryBB->getTerminator());
- new StoreInst(OldBuf, OldJmpBufPtr, true, EntryBB->getTerminator());
-
- // Add the new jumpbuf to the list.
- new StoreInst(JmpBuf, JBListHead, true, EntryBB->getTerminator());
-
- // Create the catch block. The catch block is basically a big switch
- // statement that goes to all of the invoke catch blocks.
- BasicBlock *CatchBB =
- BasicBlock::Create(F.getContext(), "setjmp.catch", &F);
-
- // Create an alloca which keeps track of the stack pointer before every
- // invoke, this allows us to properly restore the stack pointer after
- // long jumping.
- AllocaInst *StackPtr = new AllocaInst(Type::getInt8PtrTy(F.getContext()), 0,
- "stackptr", EntryBB->begin());
-
- // Create an alloca which keeps track of which invoke is currently
- // executing. For normal calls it contains zero.
- AllocaInst *InvokeNum = new AllocaInst(Type::getInt32Ty(F.getContext()), 0,
- "invokenum",EntryBB->begin());
- new StoreInst(ConstantInt::get(Type::getInt32Ty(F.getContext()), 0),
- InvokeNum, true, EntryBB->getTerminator());
-
- // Insert a load in the Catch block, and a switch on its value. By default,
- // we go to a block that just does an unwind (which is the correct action
- // for a standard call). We insert an unreachable instruction here and
- // modify the block to jump to the correct unwinding pad later.
- BasicBlock *UnwindBB = BasicBlock::Create(F.getContext(), "unwindbb", &F);
- UnreachablePlaceholder = new UnreachableInst(F.getContext(), UnwindBB);
-
- Value *CatchLoad = new LoadInst(InvokeNum, "invoke.num", true, CatchBB);
- SwitchInst *CatchSwitch =
- SwitchInst::Create(CatchLoad, UnwindBB, Invokes.size(), CatchBB);
-
- // Now that things are set up, insert the setjmp call itself.
-
- // Split the entry block to insert the conditional branch for the setjmp.
- BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(),
- "setjmp.cont");
-
- Idx[1] = ConstantInt::get(Type::getInt32Ty(F.getContext()), 0);
- Value *JmpBufPtr = GetElementPtrInst::Create(JmpBuf, Idx, "TheJmpBuf",
- EntryBB->getTerminator());
- JmpBufPtr = new BitCastInst(JmpBufPtr,
- Type::getInt8PtrTy(F.getContext()),
- "tmp", EntryBB->getTerminator());
- Value *SJRet = CallInst::Create(SetJmpFn, JmpBufPtr, "sjret",
- EntryBB->getTerminator());
-
- // Compare the return value to zero.
- Value *IsNormal = new ICmpInst(EntryBB->getTerminator(),
- ICmpInst::ICMP_EQ, SJRet,
- Constant::getNullValue(SJRet->getType()),
- "notunwind");
- // Nuke the uncond branch.
- EntryBB->getTerminator()->eraseFromParent();
-
- // Put in a new condbranch in its place.
- BranchInst::Create(ContBlock, CatchBB, IsNormal, EntryBB);
-
- // At this point, we are all set up, rewrite each invoke instruction.
- for (unsigned i = 0, e = Invokes.size(); i != e; ++i)
- rewriteExpensiveInvoke(Invokes[i], i+1, InvokeNum, StackPtr, CatchSwitch);
- }
-
- // We know that there is at least one unwind.
-
- // Create three new blocks, the block to load the jmpbuf ptr and compare
- // against null, the block to do the longjmp, and the error block for if it
- // is null. Add them at the end of the function because they are not hot.
- BasicBlock *UnwindHandler = BasicBlock::Create(F.getContext(),
- "dounwind", &F);
- BasicBlock *UnwindBlock = BasicBlock::Create(F.getContext(), "unwind", &F);
- BasicBlock *TermBlock = BasicBlock::Create(F.getContext(), "unwinderror", &F);
-
- // If this function contains an invoke, restore the old jumpbuf ptr.
- Value *BufPtr;
- if (OldJmpBufPtr) {
- // Before the return, insert a copy from the saved value to the new value.
- BufPtr = new LoadInst(OldJmpBufPtr, "oldjmpbufptr", UnwindHandler);
- new StoreInst(BufPtr, JBListHead, UnwindHandler);
- } else {
- BufPtr = new LoadInst(JBListHead, "ehlist", UnwindHandler);
- }
-
- // Load the JBList, if it's null, then there was no catch!
- Value *NotNull = new ICmpInst(*UnwindHandler, ICmpInst::ICMP_NE, BufPtr,
- Constant::getNullValue(BufPtr->getType()),
- "notnull");
- BranchInst::Create(UnwindBlock, TermBlock, NotNull, UnwindHandler);
-
- // Create the block to do the longjmp.
- // Get a pointer to the jmpbuf and longjmp.
- Value *Idx[] = { Constant::getNullValue(Type::getInt32Ty(F.getContext())),
- ConstantInt::get(Type::getInt32Ty(F.getContext()), 0) };
- Idx[0] = GetElementPtrInst::Create(BufPtr, Idx, "JmpBuf", UnwindBlock);
- Idx[0] = new BitCastInst(Idx[0],
- Type::getInt8PtrTy(F.getContext()),
- "tmp", UnwindBlock);
- Idx[1] = ConstantInt::get(Type::getInt32Ty(F.getContext()), 1);
- CallInst::Create(LongJmpFn, Idx, "", UnwindBlock);
- new UnreachableInst(F.getContext(), UnwindBlock);
-
- // Set up the term block ("throw without a catch").
- new UnreachableInst(F.getContext(), TermBlock);
-
- // Insert a call to abort()
- CallInst::Create(AbortFn, "",
- TermBlock->getTerminator())->setTailCall();
-
- // Replace the inserted unreachable with a branch to the unwind handler.
- if (UnreachablePlaceholder) {
- BranchInst::Create(UnwindHandler, UnreachablePlaceholder);
- UnreachablePlaceholder->eraseFromParent();
- }
-
- // Finally, for any returns from this function, if this function contains an
- // invoke, restore the old jmpbuf pointer to its input value.
- if (OldJmpBufPtr) {
- for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
- ReturnInst *R = Returns[i];
-
- // Before the return, insert a copy from the saved value to the new value.
- Value *OldBuf = new LoadInst(OldJmpBufPtr, "oldjmpbufptr", true, R);
- new StoreInst(OldBuf, JBListHead, true, R);
- }
- }
-
- return true;
-}
-
-bool LowerInvoke::runOnFunction(Function &F) {
- if (useExpensiveEHSupport)
- return insertExpensiveEHSupport(F);
- else
- return insertCheapEHSupport(F);
-}
Removed: llvm/trunk/test/Transforms/LowerInvoke/2004-02-29-PHICrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerInvoke/2004-02-29-PHICrash.ll?rev=204387&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerInvoke/2004-02-29-PHICrash.ll (original)
+++ llvm/trunk/test/Transforms/LowerInvoke/2004-02-29-PHICrash.ll (removed)
@@ -1,15 +0,0 @@
-; RUN: opt < %s -lowerinvoke -enable-correct-eh-support -disable-output
-
-define void @_ZNKSt11__use_cacheISt16__numpunct_cacheIcEEclERKSt6locale() {
-entry:
- br i1 false, label %then, label %UnifiedReturnBlock
-then: ; preds = %entry
- invoke void @_Znwj( )
- to label %UnifiedReturnBlock unwind label %UnifiedReturnBlock
-UnifiedReturnBlock: ; preds = %then, %then, %entry
- %UnifiedRetVal = phi i32* [ null, %entry ], [ null, %then ], [ null, %then ] ; <i32*> [#uses=0]
- ret void
-}
-
-declare void @_Znwj()
-
Removed: llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHI.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHI.ll?rev=204387&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHI.ll (original)
+++ llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHI.ll (removed)
@@ -1,17 +0,0 @@
-; RUN: opt < %s -lowerinvoke -enable-correct-eh-support -disable-output
-
-declare void @ll_listnext__listiterPtr()
-
-define void @WorkTask.fn() {
-block0:
- invoke void @ll_listnext__listiterPtr( )
- to label %block9 unwind label %block8_exception_handling
-block8_exception_handling: ; preds = %block0
- ret void
-block9: ; preds = %block0
- %w_2690 = phi { i32, i32 }* [ null, %block0 ] ; <{ i32, i32 }*> [#uses=1]
- %tmp.129 = getelementptr { i32, i32 }* %w_2690, i32 0, i32 1 ; <i32*> [#uses=1]
- %v2769 = load i32* %tmp.129 ; <i32> [#uses=0]
- ret void
-}
-
Removed: llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHIUse.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHIUse.ll?rev=204387&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHIUse.ll (original)
+++ llvm/trunk/test/Transforms/LowerInvoke/2005-08-03-InvokeWithPHIUse.ll (removed)
@@ -1,15 +0,0 @@
-; RUN: opt < %s -lowerinvoke -enable-correct-eh-support -disable-output
-
-declare fastcc i32 @ll_listnext__listiterPtr()
-
-define fastcc i32 @WorkTask.fn() {
-block0:
- %v2679 = invoke fastcc i32 @ll_listnext__listiterPtr( )
- to label %block9 unwind label %block8_exception_handling ; <i32> [#uses=1]
-block8_exception_handling: ; preds = %block0
- ret i32 0
-block9: ; preds = %block0
- %i_2689 = phi i32 [ %v2679, %block0 ] ; <i32> [#uses=1]
- ret i32 %i_2689
-}
-
Removed: llvm/trunk/test/Transforms/LowerInvoke/2008-02-14-CritEdgePhiCrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerInvoke/2008-02-14-CritEdgePhiCrash.ll?rev=204387&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerInvoke/2008-02-14-CritEdgePhiCrash.ll (original)
+++ llvm/trunk/test/Transforms/LowerInvoke/2008-02-14-CritEdgePhiCrash.ll (removed)
@@ -1,14 +0,0 @@
-; RUN: opt < %s -lowerinvoke -enable-correct-eh-support -disable-output
-; PR2029
-define i32 @main(i32 %argc, i8** %argv) {
-bb470:
- invoke i32 @main(i32 0, i8** null) to label %invcont474 unwind label
-%lpad902
-
-invcont474: ; preds = %bb470
- ret i32 0
-
-lpad902: ; preds = %bb470
- %tmp471.lcssa = phi i8* [ null, %bb470 ] ; <i8*>
- ret i32 0
-}
Removed: llvm/trunk/test/Transforms/LowerInvoke/basictest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerInvoke/basictest.ll?rev=204387&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LowerInvoke/basictest.ll (original)
+++ llvm/trunk/test/Transforms/LowerInvoke/basictest.ll (removed)
@@ -1,30 +0,0 @@
-; RUN: opt < %s -lowerinvoke -disable-output -enable-correct-eh-support
-
-
-define i32 @foo() {
- invoke i32 @foo( )
- to label %Ok unwind label %Crap ; <i32>:1 [#uses=0]
-Ok: ; preds = %0
- invoke i32 @foo( )
- to label %Ok2 unwind label %Crap ; <i32>:2 [#uses=0]
-Ok2: ; preds = %Ok
- ret i32 2
-Crap: ; preds = %Ok, %0
- ret i32 1
-}
-
-define i32 @bar(i32 %blah) {
- br label %doit
-doit: ; preds = %0
- ;; Value live across an unwind edge.
- %B2 = add i32 %blah, 1 ; <i32> [#uses=1]
- invoke i32 @foo( )
- to label %Ok unwind label %Crap ; <i32>:1 [#uses=0]
-Ok: ; preds = %doit
- invoke i32 @foo( )
- to label %Ok2 unwind label %Crap ; <i32>:2 [#uses=0]
-Ok2: ; preds = %Ok
- ret i32 2
-Crap: ; preds = %Ok, %doit
- ret i32 %B2
-}
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