[SDAG] Handle LowerOperation returning its input consistently

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

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 1b3dc160a8eb9d229ddfa3ea88aa33d9bde1564f..61c0a6fee1dc1d9dc83636dbdf56e8f600e81aa6 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -260,7 +260,7 @@ SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
     if (ConstantFPSDNode::isValueValidForType(SVT, CFP->getValueAPF()) &&
         // Only do this if the target has a native EXTLOAD instruction from
         // smaller type.
-        TLI.isLoadExtLegal(ISD::EXTLOAD, SVT) &&
+        TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
         TLI.ShouldShrinkFPConstant(OrigVT)) {
       Type *SType = SVT.getTypeForEVT(*DAG.getContext());
       LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
@@ -731,7 +731,7 @@ void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
         }
         case TargetLowering::Custom: {
           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
-          if (Res.getNode())
+          if (Res && Res != SDValue(Node, 0))
             ReplaceNode(SDValue(Node, 0), Res);
           return;
         }
@@ -843,7 +843,7 @@ void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
         }
         case TargetLowering::Custom: {
           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
-          if (Res.getNode())
+          if (Res && Res != SDValue(Node, 0))
             ReplaceNode(SDValue(Node, 0), Res);
           return;
         }
@@ -944,7 +944,8 @@ void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
       // nice to have an effective generic way of getting these benefits...
       // Until such a way is found, don't insist on promoting i1 here.
       (SrcVT != MVT::i1 ||
-       TLI.getLoadExtAction(ExtType, MVT::i1) == TargetLowering::Promote)) {
+       TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
+         TargetLowering::Promote)) {
     // Promote to a byte-sized load if not loading an integral number of
     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
     unsigned NewWidth = SrcVT.getStoreSizeInBits();
@@ -1056,7 +1057,8 @@ void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
     Chain = Ch;
   } else {
     bool isCustom = false;
-    switch (TLI.getLoadExtAction(ExtType, SrcVT.getSimpleVT())) {
+    switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
+                                 SrcVT.getSimpleVT())) {
     default: llvm_unreachable("This action is not supported yet!");
     case TargetLowering::Custom:
       isCustom = true;
@@ -1088,21 +1090,25 @@ void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
       break;
     }
     case TargetLowering::Expand:
-      if (!TLI.isLoadExtLegal(ISD::EXTLOAD, SrcVT) && TLI.isTypeLegal(SrcVT)) {
-        SDValue Load = DAG.getLoad(SrcVT, dl, Chain, Ptr, LD->getMemOperand());
-        unsigned ExtendOp;
-        switch (ExtType) {
-        case ISD::EXTLOAD:
-          ExtendOp = (SrcVT.isFloatingPoint() ?
-                      ISD::FP_EXTEND : ISD::ANY_EXTEND);
+      if (!TLI.isLoadExtLegal(ISD::EXTLOAD, Node->getValueType(0), SrcVT)) {
+        // If the source type is not legal, see if there is a legal extload to
+        // an intermediate type that we can then extend further.
+        EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
+        if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
+            TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
+          // If we are loading a legal type, this is a non-extload followed by a
+          // full extend.
+          ISD::LoadExtType MidExtType =
+              (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
+
+          SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
+                                        SrcVT, LD->getMemOperand());
+          unsigned ExtendOp =
+              ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
+          Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
+          Chain = Load.getValue(1);
           break;
-        case ISD::SEXTLOAD: ExtendOp = ISD::SIGN_EXTEND; break;
-        case ISD::ZEXTLOAD: ExtendOp = ISD::ZERO_EXTEND; break;
-        default: llvm_unreachable("Unexpected extend load type!");
         }
-        Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
-        Chain = Load.getValue(1);
-        break;
       }
 
       assert(!SrcVT.isVector() &&
@@ -3513,6 +3519,9 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node) {
                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
                                       RTLIB::FMA_PPCF128));
     break;
+  case ISD::FMAD:
+    llvm_unreachable("Illegal fmad should never be formed");
+
   case ISD::FADD:
     Results.push_back(ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
                                       RTLIB::ADD_F80, RTLIB::ADD_F128,
@@ -3539,6 +3548,21 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node) {
     break;
   }
   case ISD::FP_TO_FP16: {
+    if (!TM.Options.UseSoftFloat && TM.Options.UnsafeFPMath) {
+      SDValue Op = Node->getOperand(0);
+      MVT SVT = Op.getSimpleValueType();
+      if ((SVT == MVT::f64 || SVT == MVT::f80) &&
+          TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
+        // Under fastmath, we can expand this node into a fround followed by
+        // a float-half conversion.
+        SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
+                                       DAG.getIntPtrConstant(0));
+        Results.push_back(
+            DAG.getNode(ISD::FP_TO_FP16, dl, MVT::i16, FloatVal));
+        break;
+      }
+    }
+
     RTLIB::Libcall LC =
         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");