As part of the ongoing work in finalizing the accelerator tables, extend

[oota-llvm.git] / lib / CodeGen / SjLjEHPrepare.cpp

diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp
index 5d60bc9b751abc76f8c3fbd2a64329c16187b441..8e2f74f039299e7294ca87362257af1b7d81be23 100644 (file)
--- a/lib/CodeGen/SjLjEHPrepare.cpp
+++ b/lib/CodeGen/SjLjEHPrepare.cpp
@@ -30,6 +30,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/IRBuilder.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
@@ -68,6 +69,8 @@ namespace {
 
   private:
     bool setupEntryBlockAndCallSites(Function &F);
+    void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal,
+                              Value *SelVal);
     Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads);
     void lowerIncomingArguments(Function &F);
     void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> Invokes);
@@ -137,6 +140,38 @@ static void MarkBlocksLiveIn(BasicBlock *BB,
     MarkBlocksLiveIn(*PI, LiveBBs);
 }
 
+/// substituteLPadValues - Substitute the values returned by the landingpad
+/// instruction with those returned by the personality function.
+void SjLjEHPass::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal,
+                                      Value *SelVal) {
+  SmallVector<Value*, 8> UseWorkList(LPI->use_begin(), LPI->use_end());
+  while (!UseWorkList.empty()) {
+    Value *Val = UseWorkList.pop_back_val();
+    ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(Val);
+    if (!EVI) continue;
+    if (EVI->getNumIndices() != 1) continue;
+    if (*EVI->idx_begin() == 0)
+      EVI->replaceAllUsesWith(ExnVal);
+    else if (*EVI->idx_begin() == 1)
+      EVI->replaceAllUsesWith(SelVal);
+    if (EVI->getNumUses() == 0)
+      EVI->eraseFromParent();
+  }
+
+  if (LPI->getNumUses() == 0)  return;
+
+  // There are still some uses of LPI. Construct an aggregate with the exception
+  // values and replace the LPI with that aggregate.
+  Type *LPadType = LPI->getType();
+  Value *LPadVal = UndefValue::get(LPadType);
+  IRBuilder<>
+    Builder(llvm::next(BasicBlock::iterator(cast<Instruction>(SelVal))));
+  LPadVal = Builder.CreateInsertValue(LPadVal, ExnVal, 0, "lpad.val");
+  LPadVal = Builder.CreateInsertValue(LPadVal, SelVal, 1, "lpad.val");
+
+  LPI->replaceAllUsesWith(LPadVal);
+}
+
 /// setupFunctionContext - Allocate the function context on the stack and fill
 /// it with all of the data that we know at this point.
 Value *SjLjEHPass::
@@ -188,12 +223,7 @@ setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads) {
     ExnVal = Builder.CreateIntToPtr(ExnVal, Type::getInt8PtrTy(F.getContext()));
     Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val");
 
-    Type *LPadType = LPI->getType();
-    Value *LPadVal = UndefValue::get(LPadType);
-    LPadVal = Builder.CreateInsertValue(LPadVal, ExnVal, 0, "lpad.val");
-    LPadVal = Builder.CreateInsertValue(LPadVal, SelVal, 1, "lpad.val");
-
-    LPI->replaceAllUsesWith(LPadVal);
+    substituteLPadValues(LPI, ExnVal, SelVal);
   }
 
   // Personality function
@@ -364,13 +394,13 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
 bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
   SmallVector<ReturnInst*,     16> Returns;
   SmallVector<InvokeInst*,     16> Invokes;
-  SmallVector<LandingPadInst*, 16> LPads;
+  SmallSetVector<LandingPadInst*, 16> LPads;
 
   // 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())) {
       Invokes.push_back(II);
-      LPads.push_back(II->getUnwindDest()->getLandingPadInst());
+      LPads.insert(II->getUnwindDest()->getLandingPadInst());
     } else if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
       Returns.push_back(RI);
     }
@@ -382,7 +412,8 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
   lowerIncomingArguments(F);
   lowerAcrossUnwindEdges(F, Invokes);
 
-  Value *FuncCtx = setupFunctionContext(F, LPads);
+  Value *FuncCtx =
+    setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
   BasicBlock *EntryBB = F.begin();
   Type *Int32Ty = Type::getInt32Ty(F.getContext());