Add DAG parameter to ComputeNumSignBitsForTargetNode

This way, you can check the number of sign bits in the
operands. The depth parameter it already has is pretty useless
without this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205649 91177308-0d34-0410-b5e6-96231b3b80d8

Author: arsenm

include/llvm/Target/TargetLowering.h

@@ -1905,6 +1905,7 @@ class TargetLowering : public TargetLoweringBase {
   /// This method can be implemented by targets that want to expose additional
   /// information about sign bits to the DAG Combiner.
   virtual unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
+                                                   const SelectionDAG &DAG,
                                                    unsigned Depth = 0) const;
 
   struct DAGCombinerInfo {

lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -2422,7 +2422,7 @@ unsigned SelectionDAG::ComputeNumSignBits(SDValue Op, unsigned Depth) const{
       Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
       Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
       Op.getOpcode() == ISD::INTRINSIC_VOID) {
-    unsigned NumBits = TLI->ComputeNumSignBitsForTargetNode(Op, Depth);
+    unsigned NumBits = TLI->ComputeNumSignBitsForTargetNode(Op, *this, Depth);
     if (NumBits > 1) FirstAnswer = std::max(FirstAnswer, NumBits);
   }
 

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -1074,6 +1074,7 @@ void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
 /// targets that want to expose additional information about sign bits to the
 /// DAG Combiner.
 unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
+                                                         const SelectionDAG &,
                                                          unsigned Depth) const {
   assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
           Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||

lib/Target/X86/X86ISelLowering.cpp

@@ -16576,8 +16576,10 @@ void X86TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
   }
 }
 
-unsigned X86TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
-                                                         unsigned Depth) const {
+unsigned X86TargetLowering::ComputeNumSignBitsForTargetNode(
+  SDValue Op,
+  const SelectionDAG &,
+  unsigned Depth) const {
   // SETCC_CARRY sets the dest to ~0 for true or 0 for false.
   if (Op.getOpcode() == X86ISD::SETCC_CARRY)
     return Op.getValueType().getScalarType().getSizeInBits();

lib/Target/X86/X86ISelLowering.h

@@ -626,6 +626,7 @@ namespace llvm {
     // ComputeNumSignBitsForTargetNode - Determine the number of bits in the
     // operation that are sign bits.
     unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
+                                             const SelectionDAG &DAG,
                                              unsigned Depth) const override;
 
     bool isGAPlusOffset(SDNode *N, const GlobalValue* &GA,