[llvm] 16a67d2 - [TargetLowering] In expandFP_TO_UINT, add proper extend or truncate for the condition to feed the DstVT select.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2020-01-04T18:15:20-08:00
New Revision: 16a67d252c72332423bae6597a0685248fc3501f

URL: https://github.com/llvm/llvm-project/commit/16a67d252c72332423bae6597a0685248fc3501f
DIFF: https://github.com/llvm/llvm-project/commit/16a67d252c72332423bae6597a0685248fc3501f.diff

LOG: [TargetLowering] In expandFP_TO_UINT, add proper extend or truncate for the condition to feed the DstVT select.

Previously, for vectors we created a vselect with a condition that
didn't match what the target wanted according to getSetCCResultType.

To make up for this, X86 had a special DAG combine to detect if
the condition was all sign bits and then insert its own truncate
or extend. By adding the extend/truncate here explicitly we can
avoid that.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index c2f98458cc2f..f6e96d22c779 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -6067,6 +6067,8 @@ bool TargetLowering::expandFP_TO_UINT(SDNode *Node, SDValue &Result,
   EVT DstVT = Node->getValueType(0);
   EVT SetCCVT =
       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), SrcVT);
+  EVT DstSetCCVT =
+      getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), DstVT);
 
   // Only expand vector types if we have the appropriate vector bit operations.
   unsigned SIntOpcode = Node->isStrictFPOpcode() ? ISD::STRICT_FP_TO_SINT : 
@@ -6115,6 +6117,7 @@ bool TargetLowering::expandFP_TO_UINT(SDNode *Node, SDValue &Result,
     // TODO: Should any fast-math-flags be set for the FSUB?
     SDValue FltOfs = DAG.getSelect(dl, SrcVT, Sel,
                                    DAG.getConstantFP(0.0, dl, SrcVT), Cst);
+    Sel = DAG.getBoolExtOrTrunc(Sel, dl, DstSetCCVT, DstVT);
     SDValue IntOfs = DAG.getSelect(dl, DstVT, Sel,
                                    DAG.getConstant(0, dl, DstVT),
                                    DAG.getConstant(SignMask, dl, DstVT));
@@ -6142,6 +6145,7 @@ bool TargetLowering::expandFP_TO_UINT(SDNode *Node, SDValue &Result,
                                 DAG.getNode(ISD::FSUB, dl, SrcVT, Src, Cst));
     False = DAG.getNode(ISD::XOR, dl, DstVT, False,
                         DAG.getConstant(SignMask, dl, DstVT));
+    Sel = DAG.getBoolExtOrTrunc(Sel, dl, DstSetCCVT, DstVT);
     Result = DAG.getSelect(dl, DstVT, Sel, True, False);
   }
   return true;