Change:

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

diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 53809c62f8e8a3ee91606681b9a3a7fcd5c52eb3..fbd0c623eb693e4aad7654906ba3211fad181317 100644 (file)
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -66,17 +66,22 @@ using namespace llvm;
 void FastISel::startNewBlock() {
   LocalValueMap.clear();
 
-  // Start out as null, meaining no local-value instructions have
-  // been emitted.
-  LastLocalValue = 0;
+  EmitStartPt = 0;
 
-  // Advance the last local value past any EH_LABEL instructions.
+  // Advance the emit start point past any EH_LABEL instructions.
   MachineBasicBlock::iterator
     I = FuncInfo.MBB->begin(), E = FuncInfo.MBB->end();
   while (I != E && I->getOpcode() == TargetOpcode::EH_LABEL) {
-    LastLocalValue = I;
+    EmitStartPt = I;
     ++I;
   }
+  LastLocalValue = EmitStartPt;
+}
+
+void FastISel::flushLocalValueMap() {
+  LocalValueMap.clear();
+  LastLocalValue = EmitStartPt;
+  recomputeInsertPt();
 }
 
 bool FastISel::hasTrivialKill(const Value *V) const {
@@ -183,7 +188,7 @@ unsigned FastISel::materializeRegForValue(const Value *V, MVT VT) {
       (void) Flt.convertToInteger(x, IntBitWidth, /*isSigned=*/true,
                                 APFloat::rmTowardZero, &isExact);
       if (isExact) {
-        APInt IntVal(IntBitWidth, 2, x);
+        APInt IntVal(IntBitWidth, x);
 
         unsigned IntegerReg =
           getRegForValue(ConstantInt::get(V->getContext(), IntVal));
@@ -292,28 +297,6 @@ void FastISel::recomputeInsertPt() {
     ++FuncInfo.InsertPt;
 }
 
-/// recomputeDebugLocForMaterializedRegs - Recompute debug location for
-/// very first instruction in a basic block. All instructions emitted
-/// to materialize registers do not have location information, see
-/// enterLocalValueArea(), becase they may not be emited at the right
-/// location.
-void FastISel::recomputeDebugLocForMaterializedRegs() {
-  if (!getLastLocalValue())
-    return;
-  MachineInstr *First = FuncInfo.MBB->getFirstNonPHI();
-  if (!First->getDebugLoc().isUnknown())
-    return;
-
-  for (MachineBasicBlock::iterator I = FuncInfo.MBB->begin(),
-         E = FuncInfo.MBB->end(); I != E; ++I) {
-    DebugLoc DL = I->getDebugLoc();
-    if (!DL.isUnknown()) {
-      First->setDebugLoc(DL);
-      return;
-    }
-  }
-}
-
 FastISel::SavePoint FastISel::enterLocalValueArea() {
   MachineBasicBlock::iterator OldInsertPt = FuncInfo.InsertPt;
   DebugLoc OldDL = DL;
@@ -548,13 +531,10 @@ bool FastISel::SelectCall(const User *I) {
     unsigned Reg = 0;
     unsigned Offset = 0;
     if (const Argument *Arg = dyn_cast<Argument>(Address)) {
-      if (Arg->hasByValAttr()) {
-        // Byval arguments' frame index is recorded during argument lowering.
-        // Use this info directly.
-        Offset = FuncInfo.getByValArgumentFrameIndex(Arg);
-        if (Offset)
-          Reg = TRI.getFrameRegister(*FuncInfo.MF);
-      }
+      // Some arguments' frame index is recorded during argument lowering.
+      Offset = FuncInfo.getArgumentFrameIndex(Arg);
+      if (Offset)
+       Reg = TRI.getFrameRegister(*FuncInfo.MF);
     }
     if (!Reg)
       Reg = getRegForValue(Address);
@@ -667,6 +647,16 @@ bool FastISel::SelectCall(const User *I) {
   }
   }
 
+  // Usually, it does not make sense to initialize a value,
+  // make an unrelated function call and use the value, because
+  // it tends to be spilled on the stack. So, we move the pointer
+  // to the last local value to the beginning of the block, so that
+  // all the values which have already been materialized,
+  // appear after the call. It also makes sense to skip intrinsics
+  // since they tend to be inlined.
+  if (!isa<IntrinsicInst>(F))
+    flushLocalValueMap();
+
   // An arbitrary call. Bail.
   return false;
 }