2012-03-14 04:04:21 +08:00
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//===- SjLjEHPrepare.cpp - Eliminate Invoke & Unwind instructions ---------===//
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2009-08-18 00:41:22 +08:00
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This transformation is designed for use by code generators which use SjLj
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// based exception handling.
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//
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//===----------------------------------------------------------------------===//
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2012-12-04 00:50:05 +08:00
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/SetVector.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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2013-01-02 19:36:10 +08:00
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Module.h"
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2009-08-18 00:41:22 +08:00
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#include "llvm/Pass.h"
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2012-06-29 20:38:19 +08:00
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetLowering.h"
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2014-08-05 05:25:23 +08:00
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#include "llvm/Target/TargetSubtargetInfo.h"
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2012-06-29 20:38:19 +08:00
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/Transforms/Utils/BasicBlockUtils.h"
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#include "llvm/Transforms/Utils/Local.h"
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2010-11-06 19:45:59 +08:00
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#include <set>
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2009-08-18 00:41:22 +08:00
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using namespace llvm;
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2014-04-22 10:02:50 +08:00
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#define DEBUG_TYPE "sjljehprepare"
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2009-08-18 00:41:22 +08:00
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STATISTIC(NumInvokes, "Number of invokes replaced");
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STATISTIC(NumSpilled, "Number of registers live across unwind edges");
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namespace {
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2013-09-24 04:57:47 +08:00
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class SjLjEHPrepare : public FunctionPass {
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const TargetMachine *TM;
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Type *FunctionContextTy;
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Constant *RegisterFn;
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Constant *UnregisterFn;
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Constant *BuiltinSetjmpFn;
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Constant *FrameAddrFn;
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Constant *StackAddrFn;
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Constant *StackRestoreFn;
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Constant *LSDAAddrFn;
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Value *PersonalityFn;
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Constant *CallSiteFn;
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Constant *FuncCtxFn;
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AllocaInst *FuncCtx;
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public:
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static char ID; // Pass identification, replacement for typeid
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explicit SjLjEHPrepare(const TargetMachine *TM) : FunctionPass(ID), TM(TM) {}
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2014-03-07 17:26:03 +08:00
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bool doInitialization(Module &M) override;
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bool runOnFunction(Function &F) override;
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2013-09-24 04:57:47 +08:00
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2014-03-07 17:26:03 +08:00
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void getAnalysisUsage(AnalysisUsage &AU) const override {}
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const char *getPassName() const override {
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2013-09-24 04:57:47 +08:00
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return "SJLJ Exception Handling preparation";
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}
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2009-08-18 00:41:22 +08:00
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2013-09-24 04:57:47 +08:00
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private:
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bool setupEntryBlockAndCallSites(Function &F);
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void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, Value *SelVal);
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Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst *> LPads);
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void lowerIncomingArguments(Function &F);
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void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst *> Invokes);
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void insertCallSiteStore(Instruction *I, int Number);
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};
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2009-08-18 00:41:22 +08:00
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} // end anonymous namespace
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2012-03-14 04:04:21 +08:00
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char SjLjEHPrepare::ID = 0;
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2009-08-18 00:41:22 +08:00
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2012-03-14 04:04:21 +08:00
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// Public Interface To the SjLjEHPrepare pass.
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2013-06-20 04:51:24 +08:00
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FunctionPass *llvm::createSjLjEHPreparePass(const TargetMachine *TM) {
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return new SjLjEHPrepare(TM);
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2009-08-18 00:41:22 +08:00
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}
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2009-08-24 02:13:48 +08:00
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// doInitialization - Set up decalarations and types needed to process
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// exceptions.
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2012-03-14 04:04:21 +08:00
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bool SjLjEHPrepare::doInitialization(Module &M) {
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2009-08-18 00:41:22 +08:00
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// Build the function context structure.
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// builtin_setjmp uses a five word jbuf
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2011-07-12 22:06:48 +08:00
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Type *VoidPtrTy = Type::getInt8PtrTy(M.getContext());
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Type *Int32Ty = Type::getInt32Ty(M.getContext());
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2013-09-24 04:57:47 +08:00
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FunctionContextTy = StructType::get(VoidPtrTy, // __prev
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Int32Ty, // call_site
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ArrayType::get(Int32Ty, 4), // __data
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VoidPtrTy, // __personality
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VoidPtrTy, // __lsda
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ArrayType::get(VoidPtrTy, 5), // __jbuf
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NULL);
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RegisterFn = M.getOrInsertFunction(
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"_Unwind_SjLj_Register", Type::getVoidTy(M.getContext()),
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2014-04-14 08:51:57 +08:00
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PointerType::getUnqual(FunctionContextTy), (Type *)nullptr);
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2013-09-24 04:57:47 +08:00
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UnregisterFn = M.getOrInsertFunction(
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"_Unwind_SjLj_Unregister", Type::getVoidTy(M.getContext()),
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2014-04-14 08:51:57 +08:00
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PointerType::getUnqual(FunctionContextTy), (Type *)nullptr);
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2009-08-18 00:41:22 +08:00
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FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
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2010-05-28 07:49:24 +08:00
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StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
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2011-11-16 15:12:00 +08:00
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StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
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2009-08-18 00:41:22 +08:00
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BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp);
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LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
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2010-01-28 09:45:32 +08:00
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CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
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2011-09-29 05:56:53 +08:00
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FuncCtxFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_functioncontext);
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2014-04-14 08:51:57 +08:00
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PersonalityFn = nullptr;
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2009-08-18 00:41:22 +08:00
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return true;
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}
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2010-03-05 06:07:46 +08:00
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/// insertCallSiteStore - Insert a store of the call-site value to the
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/// function context
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2012-03-14 04:04:21 +08:00
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void SjLjEHPrepare::insertCallSiteStore(Instruction *I, int Number) {
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2012-01-27 10:02:24 +08:00
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IRBuilder<> Builder(I);
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// Get a reference to the call_site field.
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Type *Int32Ty = Type::getInt32Ty(I->getContext());
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Value *Zero = ConstantInt::get(Int32Ty, 0);
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Value *One = ConstantInt::get(Int32Ty, 1);
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Value *Idxs[2] = { Zero, One };
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Value *CallSite = Builder.CreateGEP(FuncCtx, Idxs, "call_site");
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// Insert a store of the call-site number
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2013-09-24 04:57:47 +08:00
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ConstantInt *CallSiteNoC =
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ConstantInt::get(Type::getInt32Ty(I->getContext()), Number);
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Builder.CreateStore(CallSiteNoC, CallSite, true /*volatile*/);
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2010-03-05 06:07:46 +08:00
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}
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2012-03-16 09:04:00 +08:00
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/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until
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2009-08-18 00:41:22 +08:00
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/// we reach blocks we've already seen.
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2012-03-16 09:04:00 +08:00
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static void MarkBlocksLiveIn(BasicBlock *BB,
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2014-08-21 13:55:13 +08:00
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SmallPtrSetImpl<BasicBlock *> &LiveBBs) {
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2013-09-24 04:57:47 +08:00
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if (!LiveBBs.insert(BB))
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return; // already been here.
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2009-08-18 00:41:22 +08:00
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2014-07-22 01:06:51 +08:00
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for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
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MarkBlocksLiveIn(*PI, LiveBBs);
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2009-08-18 00:41:22 +08:00
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}
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2011-12-15 06:45:33 +08:00
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/// substituteLPadValues - Substitute the values returned by the landingpad
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/// instruction with those returned by the personality function.
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2012-03-14 04:04:21 +08:00
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void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal,
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Value *SelVal) {
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2014-03-09 11:16:01 +08:00
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SmallVector<Value *, 8> UseWorkList(LPI->user_begin(), LPI->user_end());
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2011-12-15 06:45:33 +08:00
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while (!UseWorkList.empty()) {
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Value *Val = UseWorkList.pop_back_val();
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ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(Val);
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2013-09-24 04:57:47 +08:00
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if (!EVI)
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continue;
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if (EVI->getNumIndices() != 1)
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continue;
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2011-12-15 06:45:33 +08:00
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if (*EVI->idx_begin() == 0)
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EVI->replaceAllUsesWith(ExnVal);
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else if (*EVI->idx_begin() == 1)
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EVI->replaceAllUsesWith(SelVal);
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if (EVI->getNumUses() == 0)
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EVI->eraseFromParent();
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}
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2013-09-24 04:57:47 +08:00
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if (LPI->getNumUses() == 0)
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return;
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2011-12-15 06:45:33 +08:00
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// There are still some uses of LPI. Construct an aggregate with the exception
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// values and replace the LPI with that aggregate.
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Type *LPadType = LPI->getType();
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Value *LPadVal = UndefValue::get(LPadType);
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2013-09-24 04:57:47 +08:00
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IRBuilder<> Builder(
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2014-03-02 20:27:27 +08:00
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std::next(BasicBlock::iterator(cast<Instruction>(SelVal))));
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2011-12-15 06:45:33 +08:00
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LPadVal = Builder.CreateInsertValue(LPadVal, ExnVal, 0, "lpad.val");
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LPadVal = Builder.CreateInsertValue(LPadVal, SelVal, 1, "lpad.val");
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LPI->replaceAllUsesWith(LPadVal);
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}
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2011-09-28 11:14:05 +08:00
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/// setupFunctionContext - Allocate the function context on the stack and fill
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/// it with all of the data that we know at this point.
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2013-09-24 04:57:47 +08:00
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Value *SjLjEHPrepare::setupFunctionContext(Function &F,
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ArrayRef<LandingPadInst *> LPads) {
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2011-09-28 11:14:05 +08:00
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BasicBlock *EntryBB = F.begin();
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// Create an alloca for the incoming jump buffer ptr and the new jump buffer
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// that needs to be restored on all exits from the function. This is an alloca
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// because the value needs to be added to the global context list.
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2014-08-05 05:25:23 +08:00
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const TargetLowering *TLI = TM->getSubtargetImpl()->getTargetLowering();
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2011-09-28 11:14:05 +08:00
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unsigned Align =
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2013-09-24 04:57:47 +08:00
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TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy);
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2014-04-14 08:51:57 +08:00
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FuncCtx = new AllocaInst(FunctionContextTy, nullptr, Align, "fn_context",
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2013-09-24 04:57:47 +08:00
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EntryBB->begin());
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2011-09-28 11:14:05 +08:00
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// Fill in the function context structure.
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for (unsigned I = 0, E = LPads.size(); I != E; ++I) {
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LandingPadInst *LPI = LPads[I];
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IRBuilder<> Builder(LPI->getParent()->getFirstInsertionPt());
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2012-01-27 10:02:24 +08:00
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// Reference the __data field.
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2012-09-03 20:27:43 +08:00
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Value *FCData = Builder.CreateConstGEP2_32(FuncCtx, 0, 2, "__data");
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2012-01-27 10:02:24 +08:00
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// The exception values come back in context->__data[0].
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2013-09-24 04:57:47 +08:00
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Value *ExceptionAddr =
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Builder.CreateConstGEP2_32(FCData, 0, 0, "exception_gep");
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2011-09-28 11:14:05 +08:00
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Value *ExnVal = Builder.CreateLoad(ExceptionAddr, true, "exn_val");
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2012-09-03 20:27:43 +08:00
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ExnVal = Builder.CreateIntToPtr(ExnVal, Builder.getInt8PtrTy());
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2012-01-27 10:02:24 +08:00
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2013-09-24 04:57:47 +08:00
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Value *SelectorAddr =
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Builder.CreateConstGEP2_32(FCData, 0, 1, "exn_selector_gep");
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2011-09-28 11:14:05 +08:00
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Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val");
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2011-12-15 06:45:33 +08:00
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substituteLPadValues(LPI, ExnVal, SelVal);
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2011-09-28 11:14:05 +08:00
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}
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// Personality function
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2012-09-03 20:27:43 +08:00
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IRBuilder<> Builder(EntryBB->getTerminator());
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2011-09-28 11:14:05 +08:00
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if (!PersonalityFn)
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PersonalityFn = LPads[0]->getPersonalityFn();
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2013-09-24 04:57:47 +08:00
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Value *PersonalityFieldPtr =
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Builder.CreateConstGEP2_32(FuncCtx, 0, 3, "pers_fn_gep");
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Builder.CreateStore(
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Builder.CreateBitCast(PersonalityFn, Builder.getInt8PtrTy()),
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PersonalityFieldPtr, /*isVolatile=*/true);
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2011-09-28 11:14:05 +08:00
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// LSDA address
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2012-09-03 20:27:43 +08:00
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Value *LSDA = Builder.CreateCall(LSDAAddrFn, "lsda_addr");
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Value *LSDAFieldPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 4, "lsda_gep");
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Builder.CreateStore(LSDA, LSDAFieldPtr, /*isVolatile=*/true);
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2011-09-28 11:14:05 +08:00
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2011-10-04 05:15:28 +08:00
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return FuncCtx;
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2011-09-28 11:14:05 +08:00
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}
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2011-10-08 08:56:47 +08:00
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/// lowerIncomingArguments - To avoid having to handle incoming arguments
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/// specially, we lower each arg to a copy instruction in the entry block. This
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/// ensures that the argument value itself cannot be live out of the entry
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/// block.
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2012-03-14 04:04:21 +08:00
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void SjLjEHPrepare::lowerIncomingArguments(Function &F) {
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2011-10-08 08:56:47 +08:00
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BasicBlock::iterator AfterAllocaInsPt = F.begin()->begin();
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while (isa<AllocaInst>(AfterAllocaInsPt) &&
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isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsPt)->getArraySize()))
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++AfterAllocaInsPt;
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2013-09-24 04:57:47 +08:00
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for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE;
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++AI) {
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2011-10-08 08:56:47 +08:00
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Type *Ty = AI->getType();
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2014-07-15 02:21:11 +08:00
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// Use 'select i8 true, %arg, undef' to simulate a 'no-op' instruction.
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Value *TrueValue = ConstantInt::getTrue(F.getContext());
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Value *UndefValue = UndefValue::get(Ty);
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Instruction *SI = SelectInst::Create(TrueValue, AI, UndefValue,
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AI->getName() + ".tmp",
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AfterAllocaInsPt);
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AI->replaceAllUsesWith(SI);
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// Reset the operand, because it was clobbered by the RAUW above.
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SI->setOperand(1, AI);
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2011-10-08 08:56:47 +08:00
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}
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}
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/// lowerAcrossUnwindEdges - Find all variables which are alive across an unwind
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/// edge and spill them.
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2012-03-14 04:04:21 +08:00
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|
|
void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F,
|
2013-09-24 04:57:47 +08:00
|
|
|
ArrayRef<InvokeInst *> Invokes) {
|
2011-10-08 08:56:47 +08:00
|
|
|
// Finally, scan the code looking for instructions with bad live ranges.
|
2013-09-24 04:57:47 +08:00
|
|
|
for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) {
|
|
|
|
for (BasicBlock::iterator II = BB->begin(), IIE = BB->end(); II != IIE;
|
|
|
|
++II) {
|
2011-10-08 08:56:47 +08:00
|
|
|
// 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;
|
2013-09-24 04:57:47 +08:00
|
|
|
if (Inst->use_empty())
|
|
|
|
continue;
|
2011-10-08 08:56:47 +08:00
|
|
|
if (Inst->hasOneUse() &&
|
2014-03-09 11:16:01 +08:00
|
|
|
cast<Instruction>(Inst->user_back())->getParent() == BB &&
|
|
|
|
!isa<PHINode>(Inst->user_back()))
|
2013-09-24 04:57:47 +08:00
|
|
|
continue;
|
2011-10-08 08:56:47 +08:00
|
|
|
|
|
|
|
// 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.
|
2013-09-24 04:57:47 +08:00
|
|
|
SmallVector<Instruction *, 16> Users;
|
2014-03-09 11:16:01 +08:00
|
|
|
for (User *U : Inst->users()) {
|
|
|
|
Instruction *UI = cast<Instruction>(U);
|
|
|
|
if (UI->getParent() != BB || isa<PHINode>(UI))
|
|
|
|
Users.push_back(UI);
|
2011-10-08 08:56:47 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
// Find all of the blocks that this value is live in.
|
2013-09-24 04:57:47 +08:00
|
|
|
SmallPtrSet<BasicBlock *, 64> LiveBBs;
|
2012-03-16 09:04:00 +08:00
|
|
|
LiveBBs.insert(Inst->getParent());
|
2011-10-08 08:56:47 +08:00
|
|
|
while (!Users.empty()) {
|
2012-03-16 09:04:00 +08:00
|
|
|
Instruction *U = Users.back();
|
|
|
|
Users.pop_back();
|
2011-10-08 08:56:47 +08:00
|
|
|
|
2012-03-16 09:04:00 +08:00
|
|
|
if (!isa<PHINode>(U)) {
|
|
|
|
MarkBlocksLiveIn(U->getParent(), LiveBBs);
|
|
|
|
} else {
|
2011-10-08 08:56:47 +08:00
|
|
|
// Uses for a PHI node occur in their predecessor block.
|
2012-03-16 09:04:00 +08:00
|
|
|
PHINode *PN = cast<PHINode>(U);
|
2011-10-08 08:56:47 +08:00
|
|
|
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
|
|
|
|
if (PN->getIncomingValue(i) == Inst)
|
2012-03-16 09:04:00 +08:00
|
|
|
MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
|
2011-10-08 08:56:47 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2012-03-16 09:04:00 +08:00
|
|
|
// 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)) {
|
|
|
|
DEBUG(dbgs() << "SJLJ Spill: " << *Inst << " around "
|
2013-09-24 04:57:47 +08:00
|
|
|
<< UnwindBlock->getName() << "\n");
|
2012-03-16 09:04:00 +08:00
|
|
|
NeedsSpill = true;
|
|
|
|
break;
|
2011-10-08 08:56:47 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2012-03-16 09:04:00 +08:00
|
|
|
// If we decided we need a spill, do it.
|
|
|
|
// FIXME: Spilling this way is overkill, as it forces all uses of
|
|
|
|
// the value to be reloaded from the stack slot, even those that aren't
|
|
|
|
// in the unwind blocks. We should be more selective.
|
|
|
|
if (NeedsSpill) {
|
|
|
|
DemoteRegToStack(*Inst, true);
|
|
|
|
++NumSpilled;
|
2012-03-13 04:19:41 +08:00
|
|
|
}
|
2011-10-08 08:56:47 +08:00
|
|
|
}
|
|
|
|
}
|
2011-10-22 06:08:56 +08:00
|
|
|
|
|
|
|
// Go through the landing pads and remove any PHIs there.
|
|
|
|
for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
|
|
|
|
BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
|
|
|
|
LandingPadInst *LPI = UnwindBlock->getLandingPadInst();
|
|
|
|
|
|
|
|
// Place PHIs into a set to avoid invalidating the iterator.
|
2013-09-24 04:57:47 +08:00
|
|
|
SmallPtrSet<PHINode *, 8> PHIsToDemote;
|
|
|
|
for (BasicBlock::iterator PN = UnwindBlock->begin(); isa<PHINode>(PN); ++PN)
|
2011-10-22 06:08:56 +08:00
|
|
|
PHIsToDemote.insert(cast<PHINode>(PN));
|
2013-09-24 04:57:47 +08:00
|
|
|
if (PHIsToDemote.empty())
|
|
|
|
continue;
|
2011-10-22 06:08:56 +08:00
|
|
|
|
|
|
|
// Demote the PHIs to the stack.
|
2014-08-25 07:23:06 +08:00
|
|
|
for (PHINode *PN : PHIsToDemote)
|
|
|
|
DemotePHIToStack(PN);
|
2011-10-22 06:08:56 +08:00
|
|
|
|
|
|
|
// Move the landingpad instruction back to the top of the landing pad block.
|
|
|
|
LPI->moveBefore(UnwindBlock->begin());
|
|
|
|
}
|
2011-10-08 08:56:47 +08:00
|
|
|
}
|
|
|
|
|
2011-09-28 11:14:05 +08:00
|
|
|
/// setupEntryBlockAndCallSites - Setup the entry block by creating and filling
|
|
|
|
/// the function context and marking the call sites with the appropriate
|
|
|
|
/// values. These values are used by the DWARF EH emitter.
|
2012-03-14 04:04:21 +08:00
|
|
|
bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
|
2013-09-24 04:57:47 +08:00
|
|
|
SmallVector<ReturnInst *, 16> Returns;
|
|
|
|
SmallVector<InvokeInst *, 16> Invokes;
|
|
|
|
SmallSetVector<LandingPadInst *, 16> LPads;
|
2011-09-28 11:14:05 +08:00
|
|
|
|
|
|
|
// Look through the terminators of the basic blocks to find invokes.
|
|
|
|
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
|
|
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
|
2013-03-08 10:21:08 +08:00
|
|
|
if (Function *Callee = II->getCalledFunction())
|
|
|
|
if (Callee->isIntrinsic() &&
|
|
|
|
Callee->getIntrinsicID() == Intrinsic::donothing) {
|
|
|
|
// Remove the NOP invoke.
|
|
|
|
BranchInst::Create(II->getNormalDest(), II);
|
|
|
|
II->eraseFromParent();
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2011-09-28 11:14:05 +08:00
|
|
|
Invokes.push_back(II);
|
Record landing pads with a SmallSetVector to avoid multiple entries.
There may be many invokes that share one landing pad, and the previous code
would record the landing pad once for each invoke. Besides the wasted
effort, a pair of volatile loads gets inserted every time the landing pad is
processed. The rest of the code can get optimized away when a landing pad
is processed repeatedly, but the volatile loads remain, resulting in code like:
LBB35_18:
Ltmp483:
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r4, [r7, #-72]
ldr r2, [r7, #-68]
llvm-svn: 144787
2011-11-16 15:57:21 +08:00
|
|
|
LPads.insert(II->getUnwindDest()->getLandingPadInst());
|
2011-09-29 05:56:53 +08:00
|
|
|
} else if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
|
|
|
|
Returns.push_back(RI);
|
2011-09-28 11:14:05 +08:00
|
|
|
}
|
|
|
|
|
2013-09-24 04:57:47 +08:00
|
|
|
if (Invokes.empty())
|
|
|
|
return false;
|
2011-09-28 11:14:05 +08:00
|
|
|
|
2011-10-25 01:12:36 +08:00
|
|
|
NumInvokes += Invokes.size();
|
|
|
|
|
2011-10-08 08:56:47 +08:00
|
|
|
lowerIncomingArguments(F);
|
|
|
|
lowerAcrossUnwindEdges(F, Invokes);
|
|
|
|
|
Record landing pads with a SmallSetVector to avoid multiple entries.
There may be many invokes that share one landing pad, and the previous code
would record the landing pad once for each invoke. Besides the wasted
effort, a pair of volatile loads gets inserted every time the landing pad is
processed. The rest of the code can get optimized away when a landing pad
is processed repeatedly, but the volatile loads remain, resulting in code like:
LBB35_18:
Ltmp483:
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r2, [r7, #-72]
ldr r2, [r7, #-68]
ldr r4, [r7, #-72]
ldr r2, [r7, #-68]
llvm-svn: 144787
2011-11-16 15:57:21 +08:00
|
|
|
Value *FuncCtx =
|
2013-09-24 04:57:47 +08:00
|
|
|
setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
|
2011-09-29 05:56:53 +08:00
|
|
|
BasicBlock *EntryBB = F.begin();
|
2012-09-03 20:27:43 +08:00
|
|
|
IRBuilder<> Builder(EntryBB->getTerminator());
|
2011-10-04 05:15:28 +08:00
|
|
|
|
|
|
|
// Get a reference to the jump buffer.
|
2012-09-03 20:27:43 +08:00
|
|
|
Value *JBufPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 5, "jbuf_gep");
|
2011-10-04 05:15:28 +08:00
|
|
|
|
|
|
|
// Save the frame pointer.
|
2012-09-03 20:27:43 +08:00
|
|
|
Value *FramePtr = Builder.CreateConstGEP2_32(JBufPtr, 0, 0, "jbuf_fp_gep");
|
2011-10-04 05:15:28 +08:00
|
|
|
|
2012-09-03 20:27:43 +08:00
|
|
|
Value *Val = Builder.CreateCall(FrameAddrFn, Builder.getInt32(0), "fp");
|
|
|
|
Builder.CreateStore(Val, FramePtr, /*isVolatile=*/true);
|
2011-10-04 05:15:28 +08:00
|
|
|
|
|
|
|
// Save the stack pointer.
|
2012-09-03 20:27:43 +08:00
|
|
|
Value *StackPtr = Builder.CreateConstGEP2_32(JBufPtr, 0, 2, "jbuf_sp_gep");
|
2011-09-29 05:56:53 +08:00
|
|
|
|
2012-09-03 20:27:43 +08:00
|
|
|
Val = Builder.CreateCall(StackAddrFn, "sp");
|
|
|
|
Builder.CreateStore(Val, StackPtr, /*isVolatile=*/true);
|
2011-09-29 05:56:53 +08:00
|
|
|
|
|
|
|
// Call the setjmp instrinsic. It fills in the rest of the jmpbuf.
|
2012-09-03 20:27:43 +08:00
|
|
|
Value *SetjmpArg = Builder.CreateBitCast(JBufPtr, Builder.getInt8PtrTy());
|
|
|
|
Builder.CreateCall(BuiltinSetjmpFn, SetjmpArg);
|
2011-09-29 05:56:53 +08:00
|
|
|
|
|
|
|
// Store a pointer to the function context so that the back-end will know
|
|
|
|
// where to look for it.
|
2012-09-03 20:27:43 +08:00
|
|
|
Value *FuncCtxArg = Builder.CreateBitCast(FuncCtx, Builder.getInt8PtrTy());
|
|
|
|
Builder.CreateCall(FuncCtxFn, FuncCtxArg);
|
2011-09-28 11:14:05 +08:00
|
|
|
|
|
|
|
// At this point, we are all set up, update the invoke instructions to mark
|
2011-10-06 06:04:08 +08:00
|
|
|
// their call_site values.
|
2011-09-28 11:14:05 +08:00
|
|
|
for (unsigned I = 0, E = Invokes.size(); I != E; ++I) {
|
2012-01-27 10:02:24 +08:00
|
|
|
insertCallSiteStore(Invokes[I], I + 1);
|
2011-09-28 11:14:05 +08:00
|
|
|
|
|
|
|
ConstantInt *CallSiteNum =
|
2013-09-24 04:57:47 +08:00
|
|
|
ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1);
|
2011-09-28 11:14:05 +08:00
|
|
|
|
|
|
|
// Record the call site value for the back end so it stays associated with
|
|
|
|
// the invoke.
|
|
|
|
CallInst::Create(CallSiteFn, CallSiteNum, "", Invokes[I]);
|
|
|
|
}
|
|
|
|
|
|
|
|
// Mark call instructions that aren't nounwind as no-action (call_site ==
|
|
|
|
// -1). Skip the entry block, as prior to then, no function context has been
|
|
|
|
// created for this function and any unexpected exceptions thrown will go
|
|
|
|
// directly to the caller's context, which is what we want anyway, so no need
|
|
|
|
// to do anything here.
|
2011-10-04 08:16:40 +08:00
|
|
|
for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;)
|
2011-09-28 11:14:05 +08:00
|
|
|
for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I)
|
|
|
|
if (CallInst *CI = dyn_cast<CallInst>(I)) {
|
|
|
|
if (!CI->doesNotThrow())
|
2012-01-27 10:02:24 +08:00
|
|
|
insertCallSiteStore(CI, -1);
|
2011-09-28 11:14:05 +08:00
|
|
|
} else if (ResumeInst *RI = dyn_cast<ResumeInst>(I)) {
|
2012-01-27 10:02:24 +08:00
|
|
|
insertCallSiteStore(RI, -1);
|
2011-09-28 11:14:05 +08:00
|
|
|
}
|
|
|
|
|
2011-09-29 05:56:53 +08:00
|
|
|
// Register the function context and make sure it's known to not throw
|
2013-09-24 04:57:47 +08:00
|
|
|
CallInst *Register =
|
|
|
|
CallInst::Create(RegisterFn, FuncCtx, "", EntryBB->getTerminator());
|
2011-09-29 05:56:53 +08:00
|
|
|
Register->setDoesNotThrow();
|
|
|
|
|
2011-11-16 15:12:00 +08:00
|
|
|
// Following any allocas not in the entry block, update the saved SP in the
|
|
|
|
// jmpbuf to the new value.
|
|
|
|
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
|
|
|
|
if (BB == F.begin())
|
|
|
|
continue;
|
|
|
|
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
|
|
|
|
if (CallInst *CI = dyn_cast<CallInst>(I)) {
|
|
|
|
if (CI->getCalledFunction() != StackRestoreFn)
|
|
|
|
continue;
|
|
|
|
} else if (!isa<AllocaInst>(I)) {
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
|
|
|
|
StackAddr->insertAfter(I);
|
|
|
|
Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
|
|
|
|
StoreStackAddr->insertAfter(StackAddr);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2011-09-29 05:56:53 +08:00
|
|
|
// Finally, for any returns from this function, if this function contains an
|
|
|
|
// invoke, add a call to unregister the function context.
|
|
|
|
for (unsigned I = 0, E = Returns.size(); I != E; ++I)
|
2011-10-04 05:15:28 +08:00
|
|
|
CallInst::Create(UnregisterFn, FuncCtx, "", Returns[I]);
|
2011-09-29 05:56:53 +08:00
|
|
|
|
2011-09-28 11:14:05 +08:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2012-03-14 04:04:21 +08:00
|
|
|
bool SjLjEHPrepare::runOnFunction(Function &F) {
|
2011-10-25 01:12:36 +08:00
|
|
|
bool Res = setupEntryBlockAndCallSites(F);
|
2009-08-18 00:41:22 +08:00
|
|
|
return Res;
|
|
|
|
}
|