Factor out EH landing pad code into a separate function, and constify

a bunch of stuff to support it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101273 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 66 insertions, 57 deletions

diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 78e8f49..fa0d998 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -739,7 +739,7 @@ FastISel::FastISel(MachineFunction &mf,
                    DenseMap<const BasicBlock *, MachineBasicBlock *> &bm,
                    DenseMap<const AllocaInst *, int> &am
 #ifndef NDEBUG
-                   , SmallSet<Instruction*, 8> &cil
+                   , SmallSet<const Instruction *, 8> &cil
 #endif
                    )
   : MBB(0),
diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index a934adf..f88cfb0 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -305,10 +305,10 @@ GlobalVariable *llvm::ExtractTypeInfo(Value *V) {
 
 /// AddCatchInfo - Extract the personality and type infos from an eh.selector
 /// call, and add them to the specified machine basic block.
-void llvm::AddCatchInfo(CallInst &I, MachineModuleInfo *MMI,
+void llvm::AddCatchInfo(const CallInst &I, MachineModuleInfo *MMI,
                         MachineBasicBlock *MBB) {
   // Inform the MachineModuleInfo of the personality for this landing pad.
-  ConstantExpr *CE = cast<ConstantExpr>(I.getOperand(2));
+  const ConstantExpr *CE = cast<ConstantExpr>(I.getOperand(2));
   assert(CE->getOpcode() == Instruction::BitCast &&
          isa<Function>(CE->getOperand(0)) &&
          "Personality should be a function");
@@ -320,7 +320,7 @@ void llvm::AddCatchInfo(CallInst &I, MachineModuleInfo *MMI,
   unsigned N = I.getNumOperands();
 
   for (unsigned i = N - 1; i > 2; --i) {
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(i))) {
+    if (const ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(i))) {
       unsigned FilterLength = CI->getZExtValue();
       unsigned FirstCatch = i + FilterLength + !FilterLength;
       assert (FirstCatch <= N && "Invalid filter length");
@@ -357,10 +357,11 @@ void llvm::AddCatchInfo(CallInst &I, MachineModuleInfo *MMI,
   }
 }
 
-void llvm::CopyCatchInfo(BasicBlock *SrcBB, BasicBlock *DestBB,
+void llvm::CopyCatchInfo(const BasicBlock *SrcBB, const BasicBlock *DestBB,
                          MachineModuleInfo *MMI, FunctionLoweringInfo &FLI) {
-  for (BasicBlock::iterator I = SrcBB->begin(), E = --SrcBB->end(); I != E; ++I)
-    if (EHSelectorInst *EHSel = dyn_cast<EHSelectorInst>(I)) {
+  for (BasicBlock::const_iterator I = SrcBB->begin(), E = --SrcBB->end();
+       I != E; ++I)
+    if (const EHSelectorInst *EHSel = dyn_cast<EHSelectorInst>(I)) {
       // Apply the catch info to DestBB.
       AddCatchInfo(*EHSel, MMI, FLI.MBBMap[DestBB]);
 #ifndef NDEBUG
diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h
index 45a15ca..9e972dc 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h
@@ -74,8 +74,8 @@ public:
   DenseMap<const AllocaInst*, int> StaticAllocaMap;
 
 #ifndef NDEBUG
-  SmallSet<Instruction*, 8> CatchInfoLost;
-  SmallSet<Instruction*, 8> CatchInfoFound;
+  SmallSet<const Instruction *, 8> CatchInfoLost;
+  SmallSet<const Instruction *, 8> CatchInfoFound;
 #endif
 
   struct LiveOutInfo {
@@ -143,10 +143,11 @@ GlobalVariable *ExtractTypeInfo(Value *V);
 
 /// AddCatchInfo - Extract the personality and type infos from an eh.selector
 /// call, and add them to the specified machine basic block.
-void AddCatchInfo(CallInst &I, MachineModuleInfo *MMI, MachineBasicBlock *MBB);
+void AddCatchInfo(const CallInst &I,
+                  MachineModuleInfo *MMI, MachineBasicBlock *MBB);
 
 /// CopyCatchInfo - Copy catch information from DestBB to SrcBB.
-void CopyCatchInfo(BasicBlock *SrcBB, BasicBlock *DestBB,
+void CopyCatchInfo(const BasicBlock *SrcBB, const BasicBlock *DestBB,
                    MachineModuleInfo *MMI, FunctionLoweringInfo &FLI);
 
 /// hasInlineAsmMemConstraint - Return true if the inline asm instruction being
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 71fbafe..4321236 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -699,6 +699,50 @@ void SelectionDAGISel::DoInstructionSelection() {
   PostprocessISelDAG();
 }
 
+/// PrepareEHLandingPad - Emit an EH_LABEL, set up live-in registers, and
+/// do other setup for EH landing-pad blocks.
+void SelectionDAGISel::PrepareEHLandingPad(MachineBasicBlock *BB) {
+  // Add a label to mark the beginning of the landing pad.  Deletion of the
+  // landing pad can thus be detected via the MachineModuleInfo.
+  MCSymbol *Label = MF->getMMI().addLandingPad(BB);
+
+  const TargetInstrDesc &II =
+    TLI.getTargetMachine().getInstrInfo()->get(TargetOpcode::EH_LABEL);
+  BuildMI(BB, SDB->getCurDebugLoc(), II).addSym(Label);
+
+  // Mark exception register as live in.
+  unsigned Reg = TLI.getExceptionAddressRegister();
+  if (Reg) BB->addLiveIn(Reg);
+
+  // Mark exception selector register as live in.
+  Reg = TLI.getExceptionSelectorRegister();
+  if (Reg) BB->addLiveIn(Reg);
+
+  // FIXME: Hack around an exception handling flaw (PR1508): the personality
+  // function and list of typeids logically belong to the invoke (or, if you
+  // like, the basic block containing the invoke), and need to be associated
+  // with it in the dwarf exception handling tables.  Currently however the
+  // information is provided by an intrinsic (eh.selector) that can be moved
+  // to unexpected places by the optimizers: if the unwind edge is critical,
+  // then breaking it can result in the intrinsics being in the successor of
+  // the landing pad, not the landing pad itself.  This results
+  // in exceptions not being caught because no typeids are associated with
+  // the invoke.  This may not be the only way things can go wrong, but it
+  // is the only way we try to work around for the moment.
+  const BasicBlock *LLVMBB = BB->getBasicBlock();
+  const BranchInst *Br = dyn_cast<BranchInst>(LLVMBB->getTerminator());
+
+  if (Br && Br->isUnconditional()) { // Critical edge?
+    BasicBlock::const_iterator I, E;
+    for (I = LLVMBB->begin(), E = --LLVMBB->end(); I != E; ++I)
+      if (isa<EHSelectorInst>(I))
+        break;
+
+    if (I == E)
+      // No catch info found - try to extract some from the successor.
+      CopyCatchInfo(Br->getSuccessor(0), LLVMBB, &MF->getMMI(), *FuncInfo);
+  }
+}
 
 void SelectionDAGISel::SelectAllBasicBlocks(Function &Fn,
                                             MachineFunction &MF,
@@ -742,47 +786,10 @@ void SelectionDAGISel::SelectAllBasicBlocks(Function &Fn,
       }
     }
 
-    if (BB->isLandingPad()) {
-      // Add a label to mark the beginning of the landing pad.  Deletion of the
-      // landing pad can thus be detected via the MachineModuleInfo.
-      MCSymbol *Label = MF.getMMI().addLandingPad(BB);
-
-      const TargetInstrDesc &II = TII.get(TargetOpcode::EH_LABEL);
-      BuildMI(BB, SDB->getCurDebugLoc(), II).addSym(Label);
-
-      // Mark exception register as live in.
-      unsigned Reg = TLI.getExceptionAddressRegister();
-      if (Reg) BB->addLiveIn(Reg);
-
-      // Mark exception selector register as live in.
-      Reg = TLI.getExceptionSelectorRegister();
-      if (Reg) BB->addLiveIn(Reg);
-
-      // FIXME: Hack around an exception handling flaw (PR1508): the personality
-      // function and list of typeids logically belong to the invoke (or, if you
-      // like, the basic block containing the invoke), and need to be associated
-      // with it in the dwarf exception handling tables.  Currently however the
-      // information is provided by an intrinsic (eh.selector) that can be moved
-      // to unexpected places by the optimizers: if the unwind edge is critical,
-      // then breaking it can result in the intrinsics being in the successor of
-      // the landing pad, not the landing pad itself.  This results
-      // in exceptions not being caught because no typeids are associated with
-      // the invoke.  This may not be the only way things can go wrong, but it
-      // is the only way we try to work around for the moment.
-      BranchInst *Br = dyn_cast<BranchInst>(LLVMBB->getTerminator());
-
-      if (Br && Br->isUnconditional()) { // Critical edge?
-        BasicBlock::iterator I, E;
-        for (I = LLVMBB->begin(), E = --LLVMBB->end(); I != E; ++I)
-          if (isa<EHSelectorInst>(I))
-            break;
-
-        if (I == E)
-          // No catch info found - try to extract some from the successor.
-          CopyCatchInfo(Br->getSuccessor(0), LLVMBB, &MF.getMMI(), *FuncInfo);
-      }
-    }
-
+    // Setup an EH landing-pad block.
+    if (BB->isLandingPad())
+      PrepareEHLandingPad(BB);
+    
     // Before doing SelectionDAG ISel, see if FastISel has been requested.
     if (FastIS && !SuppressFastISel) {
       // Emit code for any incoming arguments. This must happen before
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index e19f969..633115b 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -58,7 +58,7 @@ public:
                        DenseMap<const BasicBlock *, MachineBasicBlock *> &bm,
                        DenseMap<const AllocaInst *, int> &am
 #ifndef NDEBUG
-                       , SmallSet<Instruction*, 8> &cil
+                       , SmallSet<const Instruction *, 8> &cil
 #endif
                        )
     : FastISel(mf, vm, bm, am
@@ -1755,7 +1755,7 @@ namespace llvm {
                         DenseMap<const BasicBlock *, MachineBasicBlock *> &bm,
                         DenseMap<const AllocaInst *, int> &am
 #ifndef NDEBUG
-                        , SmallSet<Instruction*, 8> &cil
+                        , SmallSet<const Instruction *, 8> &cil
 #endif
                         ) {
     return new X86FastISel(mf, vm, bm, am
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 9362d37..6e6d2f5 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2410,7 +2410,7 @@ X86TargetLowering::createFastISel(MachineFunction &mf,
                             DenseMap<const BasicBlock*, MachineBasicBlock*> &bm,
                             DenseMap<const AllocaInst *, int> &am
 #ifndef NDEBUG
-                          , SmallSet<Instruction*, 8> &cil
+                          , SmallSet<const Instruction *, 8> &cil
 #endif
                                   ) {
   return X86::createFastISel(mf, vm, bm, am
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index d978676..9c0d731 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -581,7 +581,7 @@ namespace llvm {
                    DenseMap<const BasicBlock *, MachineBasicBlock *> &,
                    DenseMap<const AllocaInst *, int> &
 #ifndef NDEBUG
-                   , SmallSet<Instruction*, 8> &
+                   , SmallSet<const Instruction *, 8> &
 #endif
                    );
 
@@ -821,7 +821,7 @@ namespace llvm {
                            DenseMap<const BasicBlock *, MachineBasicBlock *> &,
                            DenseMap<const AllocaInst *, int> &
 #ifndef NDEBUG
-                           , SmallSet<Instruction*, 8> &
+                           , SmallSet<const Instruction*, 8> &
 #endif
                            );
   }