Disable this code, which broke many tests last night

[oota-llvm.git] / lib / CodeGen / SelectionDAG / SelectionDAGISel.cpp

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 6ba00bccdf88fd41f92e032151767c13e8f3b816..b587e3697db5aef6b874a65bd9e1d7687ffa1ef6 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -36,11 +36,6 @@
 #include <iostream>
 using namespace llvm;
 
-static cl::opt<bool>
-SplitPHICritEdges("split-phi-constant-crit-edges", cl::Hidden,
-         cl::desc("Split critical edges for PHI values that are constants"));
-
-
 #ifndef _NDEBUG
 static cl::opt<bool>
 ViewDAGs("view-isel-dags", cl::Hidden,
@@ -342,7 +337,7 @@ public:
   void visitUnwind(UnwindInst &I) { assert(0 && "TODO"); }
 
   //
-  void visitBinary(User &I, unsigned Opcode);
+  void visitBinary(User &I, unsigned Opcode, bool isShift = false);
   void visitAdd(User &I) { visitBinary(I, ISD::ADD); }
   void visitSub(User &I);
   void visitMul(User &I) { visitBinary(I, ISD::MUL); }
@@ -355,9 +350,9 @@ public:
   void visitAnd(User &I) { visitBinary(I, ISD::AND); }
   void visitOr (User &I) { visitBinary(I, ISD::OR); }
   void visitXor(User &I) { visitBinary(I, ISD::XOR); }
-  void visitShl(User &I) { visitBinary(I, ISD::SHL); }
+  void visitShl(User &I) { visitBinary(I, ISD::SHL, true); }
   void visitShr(User &I) {
-    visitBinary(I, I.getType()->isUnsigned() ? ISD::SRL : ISD::SRA);
+    visitBinary(I, I.getType()->isUnsigned() ? ISD::SRL : ISD::SRA, true);
   }
 
   void visitSetCC(User &I, ISD::CondCode SignedOpc, ISD::CondCode UnsignedOpc);
@@ -491,11 +486,11 @@ void SelectionDAGLowering::visitSub(User &I) {
   visitBinary(I, ISD::SUB);
 }
 
-void SelectionDAGLowering::visitBinary(User &I, unsigned Opcode) {
+void SelectionDAGLowering::visitBinary(User &I, unsigned Opcode, bool isShift) {
   SDOperand Op1 = getValue(I.getOperand(0));
   SDOperand Op2 = getValue(I.getOperand(1));
 
-  if (isa<ShiftInst>(I))
+  if (isShift)
     Op2 = DAG.getNode(ISD::ZERO_EXTEND, TLI.getShiftAmountTy(), Op2);
 
   setValue(&I, DAG.getNode(Opcode, Op1.getValueType(), Op1, Op2));
@@ -860,6 +855,20 @@ void SelectionDAGLowering::visitFree(FreeInst &I) {
   DAG.setRoot(Result.second);
 }
 
+// InsertAtEndOfBasicBlock - This method should be implemented by targets that
+// mark instructions with the 'usesCustomDAGSchedInserter' flag.  These
+// instructions are special in various ways, which require special support to
+// insert.  The specified MachineInstr is created but not inserted into any
+// basic blocks, and the scheduler passes ownership of it to this method.
+MachineBasicBlock *TargetLowering::InsertAtEndOfBasicBlock(MachineInstr *MI,
+                                                       MachineBasicBlock *MBB) {
+  std::cerr << "If a target marks an instruction with "
+               "'usesCustomDAGSchedInserter', it must implement "
+               "TargetLowering::InsertAtEndOfBasicBlock!\n";
+  abort();
+  return 0;  
+}
+
 SDOperand TargetLowering::LowerVAStart(SDOperand Chain,
                                        SDOperand VAListP, Value *VAListV,
                                        SelectionDAG &DAG) {
@@ -966,8 +975,8 @@ unsigned SelectionDAGISel::MakeReg(MVT::ValueType VT) {
 }
 
 void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const {
-  if (!SplitPHICritEdges)
-    AU.setPreservesAll();
+  // FIXME: we only modify the CFG to split critical edges.  This
+  // updates dom and loop info.
 }
 
 
@@ -979,15 +988,14 @@ bool SelectionDAGISel::runOnFunction(Function &Fn) {
   // First pass, split all critical edges for PHI nodes with incoming values
   // that are constants, this way the load of the constant into a vreg will not
   // be placed into MBBs that are used some other way.
-  if (SplitPHICritEdges)
-    for (Function::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
-      PHINode *PN;
-      for (BasicBlock::iterator BBI = BB->begin();
-           (PN = dyn_cast<PHINode>(BBI)); ++BBI)
-        for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
-          if (isa<Constant>(PN->getIncomingValue(i)))
-            SplitCriticalEdge(PN->getIncomingBlock(i), BB);
-    }
+  for (Function::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
+    PHINode *PN;
+    for (BasicBlock::iterator BBI = BB->begin();
+         (PN = dyn_cast<PHINode>(BBI)); ++BBI)
+      for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+        if (isa<Constant>(PN->getIncomingValue(i)))
+          SplitCriticalEdge(PN->getIncomingBlock(i), BB);
+  }
 
   FunctionLoweringInfo FuncInfo(TLI, Fn, MF);
 
@@ -1069,9 +1077,15 @@ LowerArguments(BasicBlock *BB, SelectionDAGLowering &SDL,
            AI != E; ++AI,++a)
         if (!AI->use_empty()) {
           SDL.setValue(AI, Args[a]);
-          SDOperand Copy =
-            CopyValueToVirtualRegister(SDL, AI, FuncInfo.ValueMap[AI]);
-          UnorderedChains.push_back(Copy);
+          
+          if (0 && IsOnlyUsedInOneBasicBlock(AI) == F.begin()) {
+            // Only used in the entry block, no need to copy it to a vreg for
+            // other blocks.
+          } else {
+            SDOperand Copy =
+              CopyValueToVirtualRegister(SDL, AI, FuncInfo.ValueMap[AI]);
+            UnorderedChains.push_back(Copy);
+          }
         }
     } else {
       // Otherwise, if any argument is only accessed in a single basic block,
@@ -1234,12 +1248,12 @@ void SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB, MachineFunction &MF,
   DEBUG(std::cerr << "Legalized selection DAG:\n");
   DEBUG(DAG.dump());
 
+  if (ViewDAGs) DAG.viewGraph();
+
   // Third, instruction select all of the operations to machine code, adding the
   // code to the MachineBasicBlock.
   InstructionSelectBasicBlock(DAG);
 
-  if (ViewDAGs) DAG.viewGraph();
-
   DEBUG(std::cerr << "Selected machine code:\n");
   DEBUG(BB->dump());