From afcb5b5ee854474a50dc4642a6e6ecc15acfe8cc Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Sat, 28 Jan 2012 01:10:01 +0000
Subject: Revert r149159 until I can fix tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149162 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/DwarfEHPrepare.cpp | 93 +++++++++++++++---------------------------
 1 file changed, 32 insertions(+), 61 deletions(-)

(limited to 'lib/CodeGen/DwarfEHPrepare.cpp')

diff --git a/lib/CodeGen/DwarfEHPrepare.cpp b/lib/CodeGen/DwarfEHPrepare.cpp
index 22f7b1c6d6..f2b2977275 100644
--- a/lib/CodeGen/DwarfEHPrepare.cpp
+++ b/lib/CodeGen/DwarfEHPrepare.cpp
@@ -39,7 +39,6 @@ namespace {
     Constant *RewindFunction;
 
     bool InsertUnwindResumeCalls(Function &Fn);
-    Instruction *GetExceptionObject(ResumeInst *RI);
 
   public:
     static char ID; // Pass identification, replacement for typeid.
@@ -65,46 +64,6 @@ FunctionPass *llvm::createDwarfEHPass(const TargetMachine *tm) {
   return new DwarfEHPrepare(tm);
 }
 
-/// 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.
-Instruction *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {
-  Value *V = RI->getOperand(0);
-  Instruction *ExnObj = 0;
-  InsertValueInst *SelIVI = dyn_cast<InsertValueInst>(V);
-  LoadInst *SelLoad = 0;
-  InsertValueInst *ExcIVI = 0;
-  bool EraseIVIs = false;
-
-  if (SelIVI) {
-    if (SelIVI->getNumIndices() == 1 && *SelIVI->idx_begin() == 1) {
-      ExcIVI = dyn_cast<InsertValueInst>(SelIVI->getOperand(0));
-      if (ExcIVI && isa<UndefValue>(ExcIVI->getOperand(0)) &&
-          ExcIVI->getNumIndices() == 1 && *ExcIVI->idx_begin() == 0) {
-        ExnObj = cast<Instruction>(ExcIVI->getOperand(1));
-        SelLoad = dyn_cast<LoadInst>(SelIVI->getOperand(1));
-        EraseIVIs = true;
-      }
-    }
-  }
-
-  if (!ExnObj)
-    ExnObj = ExtractValueInst::Create(RI->getOperand(0), 0, "exn.obj", RI);
-
-  RI->eraseFromParent();
-
-  if (EraseIVIs) {
-    if (SelIVI->getNumUses() == 0)
-      SelIVI->eraseFromParent();
-    if (ExcIVI->getNumUses() == 0)
-      ExcIVI->eraseFromParent();
-    if (SelLoad && SelLoad->getNumUses() == 0)
-      SelLoad->eraseFromParent();
-  }
-
-  return ExnObj;
-}
-
 /// InsertUnwindResumeCalls - Convert the ResumeInsts that are still present
 /// into calls to the appropriate _Unwind_Resume function.
 bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
@@ -132,26 +91,8 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
 
   // Create the basic block where the _Unwind_Resume call will live.
   LLVMContext &Ctx = Fn.getContext();
-  unsigned ResumesSize = Resumes.size();
-
-  if (ResumesSize == 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();
-    BasicBlock *UnwindBB = RI->getParent();
-    Instruction *ExnObj = GetExceptionObject(RI);
-
-    // Call the _Unwind_Resume function.
-    CallInst *CI = CallInst::Create(RewindFunction, ExnObj, "", UnwindBB);
-    CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME));
-
-    // We never expect _Unwind_Resume to return.
-    new UnreachableInst(Ctx, UnwindBB);
-    return true;
-  }
-
   BasicBlock *UnwindBB = BasicBlock::Create(Ctx, "unwind_resume", &Fn);
-  PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), ResumesSize,
+  PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), Resumes.size(),
                                 "exn.obj", UnwindBB);
 
   // Extract the exception object from the ResumeInst and add it to the PHI node
@@ -161,8 +102,38 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
     ResumeInst *RI = *I;
     BranchInst::Create(UnwindBB, RI->getParent());
 
-    Instruction *ExnObj = GetExceptionObject(RI);
+    Value *V = RI->getOperand(0);
+    Instruction *ExnObj = 0;
+    InsertValueInst *SelIVI = dyn_cast<InsertValueInst>(V);
+    LoadInst *SelLoad = 0;
+    InsertValueInst *ExcIVI = 0;
+    bool EraseIVIs = false;
+    if (SelIVI) {
+      if (SelIVI->getNumIndices() == 1 && *SelIVI->idx_begin() == 1) {
+        ExcIVI = dyn_cast<InsertValueInst>(SelIVI->getOperand(0));
+        if (ExcIVI && isa<UndefValue>(ExcIVI->getOperand(0)) &&
+            ExcIVI->getNumIndices() == 1 && *ExcIVI->idx_begin() == 0) {
+          ExnObj = cast<Instruction>(ExcIVI->getOperand(1));
+          SelLoad = dyn_cast<LoadInst>(SelIVI->getOperand(1));
+          EraseIVIs = true;
+        }
+      }
+    }
+
+    if (!ExnObj)
+      ExnObj = ExtractValueInst::Create(RI->getOperand(0), 0, "exn.obj", RI);
+
     PN->addIncoming(ExnObj, RI->getParent());
+    RI->eraseFromParent();
+
+    if (EraseIVIs) {
+      if (SelIVI->getNumUses() == 0)
+        SelIVI->eraseFromParent();
+      if (ExcIVI->getNumUses() == 0)
+        ExcIVI->eraseFromParent();
+      if (SelLoad && SelLoad->getNumUses() == 0)
+        SelLoad->eraseFromParent();
+    }
 
     ++NumResumesLowered;
   }
-- 
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