From 1a412af4f19c45c8d947ae2912db6ac3aae59219 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Wed, 6 Jan 2016 19:26:30 +0000
Subject: [PATCH] [WinEH] Remove calculateCatchReturnSuccessorColors

The functionality that calculateCatchReturnSuccessorColors provides was
once non-trivial: it was a computation layered on top of funclet
coloring.

These days, LLVM IR directly encodes what
calculateCatchReturnSuccessorColors computed, obsoleting the need for
it.

No functionality change is intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256965 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/WinEHFuncInfo.h           |  5 -----
 .../SelectionDAG/FunctionLoweringInfo.cpp      |  5 ++---
 .../SelectionDAG/SelectionDAGBuilder.cpp       |  9 +++++++--
 lib/CodeGen/WinEHPrepare.cpp                   | 18 ------------------
 4 files changed, 9 insertions(+), 28 deletions(-)

diff --git a/include/llvm/CodeGen/WinEHFuncInfo.h b/include/llvm/CodeGen/WinEHFuncInfo.h
index f6ad7a8572a..46c1029f62c 100644
--- a/include/llvm/CodeGen/WinEHFuncInfo.h
+++ b/include/llvm/CodeGen/WinEHFuncInfo.h
@@ -93,8 +93,6 @@ struct WinEHFuncInfo {
   DenseMap<const Instruction *, int> EHPadStateMap;
   DenseMap<const FuncletPadInst *, int> FuncletBaseStateMap;
   DenseMap<const InvokeInst *, int> InvokeStateMap;
-  DenseMap<const CatchReturnInst *, const BasicBlock *>
-      CatchRetSuccessorColorMap;
   DenseMap<MCSymbol *, std::pair<int, MCSymbol *>> LabelToStateMap;
   SmallVector<CxxUnwindMapEntry, 4> CxxUnwindMap;
   SmallVector<WinEHTryBlockMapEntry, 4> TryBlockMap;
@@ -125,8 +123,5 @@ void calculateSEHStateNumbers(const Function *ParentFn,
                               WinEHFuncInfo &FuncInfo);
 
 void calculateClrEHStateNumbers(const Function *Fn, WinEHFuncInfo &FuncInfo);
-
-void calculateCatchReturnSuccessorColors(const Function *Fn,
-                                         WinEHFuncInfo &FuncInfo);
 }
 #endif // LLVM_CODEGEN_WINEHFUNCINFO_H
diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index b62bd2bd63e..be5a7034be4 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -271,6 +271,8 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
     }
   }
 
+  WinEHFuncInfo &EHInfo = *MF->getWinEHFuncInfo();
+
   // Mark landing pad blocks.
   SmallVector<const LandingPadInst *, 4> LPads;
   for (BB = Fn->begin(); BB != EB; ++BB) {
@@ -289,7 +291,6 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
     return;
 
   // Calculate state numbers if we haven't already.
-  WinEHFuncInfo &EHInfo = *MF->getWinEHFuncInfo();
   if (Personality == EHPersonality::MSVC_CXX)
     calculateWinCXXEHStateNumbers(&fn, EHInfo);
   else if (isAsynchronousEHPersonality(Personality))
@@ -297,8 +298,6 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
   else if (Personality == EHPersonality::CoreCLR)
     calculateClrEHStateNumbers(&fn, EHInfo);
 
-  calculateCatchReturnSuccessorColors(&fn, EHInfo);
-
   // Map all BB references in the WinEH data to MBBs.
   for (WinEHTryBlockMapEntry &TBME : EHInfo.TryBlockMap) {
     for (WinEHHandlerType &H : TBME.HandlerArray) {
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index e446a934554..45ae39af760 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1205,8 +1205,13 @@ void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) {
   // Figure out the funclet membership for the catchret's successor.
   // This will be used by the FuncletLayout pass to determine how to order the
   // BB's.
-  WinEHFuncInfo *EHInfo = DAG.getMachineFunction().getWinEHFuncInfo();
-  const BasicBlock *SuccessorColor = EHInfo->CatchRetSuccessorColorMap[&I];
+  // A 'catchret' returns to the outer scope's color.
+  Value *ParentPad = I.getParentPad();
+  const BasicBlock *SuccessorColor;
+  if (isa<ConstantTokenNone>(ParentPad))
+    SuccessorColor = &FuncInfo.Fn->getEntryBlock();
+  else
+    SuccessorColor = cast<Instruction>(ParentPad)->getParent();
   assert(SuccessorColor && "No parent funclet for catchret!");
   MachineBasicBlock *SuccessorColorMBB = FuncInfo.MBBMap[SuccessorColor];
   assert(SuccessorColorMBB && "No MBB for SuccessorColor!");
diff --git a/lib/CodeGen/WinEHPrepare.cpp b/lib/CodeGen/WinEHPrepare.cpp
index 2426c27d43d..f112b1bb3b9 100644
--- a/lib/CodeGen/WinEHPrepare.cpp
+++ b/lib/CodeGen/WinEHPrepare.cpp
@@ -664,24 +664,6 @@ void WinEHPrepare::colorFunclets(Function &F) {
   }
 }
 
-void llvm::calculateCatchReturnSuccessorColors(const Function *Fn,
-                                               WinEHFuncInfo &FuncInfo) {
-  for (const BasicBlock &BB : *Fn) {
-    const auto *CatchRet = dyn_cast<CatchReturnInst>(BB.getTerminator());
-    if (!CatchRet)
-      continue;
-    // A 'catchret' returns to the outer scope's color.
-    Value *ParentPad = CatchRet->getParentPad();
-    const BasicBlock *Color;
-    if (isa<ConstantTokenNone>(ParentPad))
-      Color = &Fn->getEntryBlock();
-    else
-      Color = cast<Instruction>(ParentPad)->getParent();
-    // Record the catchret successor's funclet membership.
-    FuncInfo.CatchRetSuccessorColorMap[CatchRet] = Color;
-  }
-}
-
 void WinEHPrepare::demotePHIsOnFunclets(Function &F) {
   // Strip PHI nodes off of EH pads.
   SmallVector<PHINode *, 16> PHINodes;
-- 
2.34.1