Roll out r126169 and r126170 in an attempt to fix the selfhost bot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126185 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 9 insertions, 59 deletions

diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 8adaf05..98582ba 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -127,13 +127,10 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf) {
     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
       // Mark values used outside their block as exported, by allocating
       // a virtual register for them.
-      if (!EnableFastISel && isa<PHINode>(I)) {
-        PHIDestRegs.insert(InitializeRegForValue(I));
-      } else if (isUsedOutsideOfDefiningBlock(I)) {
+      if (isUsedOutsideOfDefiningBlock(I))
         if (!isa<AllocaInst>(I) ||
             !StaticAllocaMap.count(cast<AllocaInst>(I)))
           InitializeRegForValue(I);
-      }
 
       // Collect llvm.dbg.declare information. This is done now instead of
       // during the initial isel pass through the IR so that it is done
@@ -222,9 +219,6 @@ void FunctionLoweringInfo::clear() {
   CatchInfoFound.clear();
 #endif
   LiveOutRegInfo.clear();
-  VisitedBBs.clear();
-  PHIDestRegs.clear();
-  PHISrcToDestMap.clear();
   ArgDbgValues.clear();
   ByValArgFrameIndexMap.clear();
   RegFixups.clear();
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c1be3e9..452f561 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -644,10 +644,7 @@ SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG,
           !RegisterVT.isInteger() || RegisterVT.isVector() ||
           !FuncInfo.LiveOutRegInfo.inBounds(Regs[Part+i]))
         continue;
-
-      if (FuncInfo.PHIDestRegs.count(Regs[Part+i]) && !FuncInfo.AllPredsVisited)
-        continue;
-
+      
       const FunctionLoweringInfo::LiveOutInfo &LOI =
         FuncInfo.LiveOutRegInfo[Regs[Part+i]];
 
@@ -6469,9 +6466,6 @@ SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {
         }
       }
 
-      if (!EnableFastISel)
-        FuncInfo.PHISrcToDestMap[Reg] = FuncInfo.ValueMap[PN];
-
       // Remember that this register needs to added to the machine PHI node as
       // the input for this MBB.
       SmallVector<EVT, 4> ValueVTs;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 450757f..ae63f2e 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -49,7 +49,6 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/ADT/Statistic.h"
 #include <algorithm>
 using namespace llvm;
@@ -471,13 +470,6 @@ void SelectionDAGISel::ComputeLiveOutVRegInfo() {
     if (!TargetRegisterInfo::isVirtualRegister(DestReg))
       continue;
 
-    bool IsPHI = false;
-    DenseMap<unsigned, unsigned>::const_iterator It = FuncInfo->PHISrcToDestMap.find(DestReg);
-    if (It != FuncInfo->PHISrcToDestMap.end()) {
-      IsPHI = true;
-      DestReg = It->second;
-    }
-
     // Ignore non-scalar or non-integer values.
     SDValue Src = N->getOperand(2);
     EVT SrcVT = Src.getValueType();
@@ -489,27 +481,14 @@ void SelectionDAGISel::ComputeLiveOutVRegInfo() {
     CurDAG->ComputeMaskedBits(Src, Mask, KnownZero, KnownOne);
 
     // Only install this information if it tells us something.
-    if (!IsPHI && NumSignBits == 1 && KnownZero == 0 && KnownOne == 0)
-      continue;
-
-    FuncInfo->LiveOutRegInfo.grow(DestReg);
-    FunctionLoweringInfo::LiveOutInfo &LOI = FuncInfo->LiveOutRegInfo[DestReg];
-
-    // If this is a PHI and there is existing information, merge it with the
-    // information from this block.
-    if (IsPHI && LOI.IsValid) {
+    if (NumSignBits != 1 || KnownZero != 0 || KnownOne != 0) {
+      FuncInfo->LiveOutRegInfo.grow(DestReg);
       FunctionLoweringInfo::LiveOutInfo &LOI =
         FuncInfo->LiveOutRegInfo[DestReg];
-      LOI.NumSignBits = std::min(LOI.NumSignBits, NumSignBits);
-      LOI.KnownOne &= KnownOne;
-      LOI.KnownZero &= KnownZero;
-      continue;
+      LOI.NumSignBits = NumSignBits;
+      LOI.KnownOne = KnownOne;
+      LOI.KnownZero = KnownZero;
     }
-
-    LOI.NumSignBits = NumSignBits;
-    LOI.KnownOne = KnownOne;
-    LOI.KnownZero = KnownZero;
-    LOI.IsValid = true;
   } while (!Worklist.empty());
 }
 
@@ -853,28 +832,11 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
     FastIS = TLI.createFastISel(*FuncInfo);
 
   // Iterate over all basic blocks in the function.
-  ReversePostOrderTraversal<const Function*> RPOT(&Fn);
-  for (ReversePostOrderTraversal<const Function*>::rpo_iterator
-       I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
-    const BasicBlock *LLVMBB = *I;
+  for (Function::const_iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
+    const BasicBlock *LLVMBB = &*I;
 #ifndef NDEBUG
     CheckLineNumbers(LLVMBB);
 #endif
-
-    if (EnableFastISel) {
-      FuncInfo->AllPredsVisited = false;
-    } else {
-      FuncInfo->AllPredsVisited = true;
-      for (const_pred_iterator PI = pred_begin(LLVMBB), PE = pred_end(LLVMBB);
-           PI != PE; ++PI) {
-        if (!FuncInfo->VisitedBBs.count(*PI)) {
-          FuncInfo->AllPredsVisited = false;
-          break;
-        }
-      }
-      FuncInfo->VisitedBBs.insert(LLVMBB);
-    }
-
     FuncInfo->MBB = FuncInfo->MBBMap[LLVMBB];
     FuncInfo->InsertPt = FuncInfo->MBB->getFirstNonPHI();