[globalisel][tablegen] Generalize pointer-type inference by introducing ptypeN. NFC

ptypeN is functionally the same as typeN except that it informs the
SelectionDAG importer that an operand should be treated as a pointer even
if it was written as iN. This is important for patterns that use iN instead
of iPTR to represent pointers. E.g.:
  (set GPR64:$dst, (load GPR64:$addr))

Previously, this was handled as a hardcoded special case for the appropriate
operands to G_LOAD and G_STORE.

llvm-svn: 318574

llvm/include/llvm/Target/GenericOpcodes.td

@@ -469,7 +469,7 @@ def G_FLOG2 : Instruction {
 // Generic load. Expects a MachineMemOperand in addition to explicit operands.
 def G_LOAD : Instruction {
   let OutOperandList = (outs type0:$dst);
-  let InOperandList = (ins type1:$addr);
+  let InOperandList = (ins ptype1:$addr);
   let hasSideEffects = 0;
   let mayLoad = 1;
 }
@@ -477,7 +477,7 @@ def G_LOAD : Instruction {
 // Generic store. Expects a MachineMemOperand in addition to explicit operands.
 def G_STORE : Instruction {
   let OutOperandList = (outs);
-  let InOperandList = (ins type0:$src, type1:$addr);
+  let InOperandList = (ins type0:$src, ptype1:$addr);
   let hasSideEffects = 0;
   let mayStore = 1;
 }

llvm/include/llvm/Target/Target.td

@@ -792,6 +792,7 @@ def f64imm : Operand<f64>;
 // have the same LLT).
 class TypedOperand<string Ty> : Operand<untyped> {
   let OperandType = Ty;
+  bit IsPointer = 0;
 }
 
 def type0 : TypedOperand<"OPERAND_GENERIC_0">;
@@ -801,6 +802,15 @@ def type3 : TypedOperand<"OPERAND_GENERIC_3">;
 def type4 : TypedOperand<"OPERAND_GENERIC_4">;
 def type5 : TypedOperand<"OPERAND_GENERIC_5">;
 
+let IsPointer = 1 in {
+  def ptype0 : TypedOperand<"OPERAND_GENERIC_0">;
+  def ptype1 : TypedOperand<"OPERAND_GENERIC_1">;
+  def ptype2 : TypedOperand<"OPERAND_GENERIC_2">;
+  def ptype3 : TypedOperand<"OPERAND_GENERIC_3">;
+  def ptype4 : TypedOperand<"OPERAND_GENERIC_4">;
+  def ptype5 : TypedOperand<"OPERAND_GENERIC_5">;
+}
+
 /// zero_reg definition - Special node to stand for the zero register.
 ///
 def zero_reg;

llvm/utils/TableGen/CodeGenInstruction.cpp

@@ -430,6 +430,17 @@ FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
   return Res;
 }
 
+bool CodeGenInstruction::isOperandAPointer(unsigned i) const {
+  if (DagInit *ConstraintList = TheDef->getValueAsDag("InOperandList")) {
+    if (i < ConstraintList->getNumArgs()) {
+      if (DefInit *Constraint = dyn_cast<DefInit>(ConstraintList->getArg(i))) {
+        return Constraint->getDef()->isSubClassOf("TypedOperand") &&
+               Constraint->getDef()->getValueAsBit("IsPointer");
+      }
+    }
+  }
+  return false;
+}
 
 //===----------------------------------------------------------------------===//
 /// CodeGenInstAlias Implementation

llvm/utils/TableGen/CodeGenInstruction.h

@@ -284,6 +284,12 @@ template <typename T> class ArrayRef;
     /// include text from the specified variant, returning the new string.
     static std::string FlattenAsmStringVariants(StringRef AsmString,
                                                 unsigned Variant);
+
+    // Is the specified operand in a generic instruction implicitly a pointer.
+    // This can be used on intructions that use typeN or ptypeN to identify
+    // operands that should be considered as pointers even though SelectionDAG
+    // didn't make a distinction between integer and pointers.
+    bool isOperandAPointer(unsigned i) const;
   };
 
 

llvm/utils/TableGen/GlobalISelEmitter.cpp

@@ -2546,10 +2546,7 @@ Expected<InstructionMatcher &> GlobalISelEmitter::createAndImportSelDAGMatcher(
       // SelectionDAG allows pointers to be represented with iN since it doesn't
       // distinguish between pointers and integers but they are different types in GlobalISel.
       // Coerce integers to pointers to address space 0 if the context indicates a pointer.
-      // TODO: Find a better way to do this, SDTCisPtrTy?
+      bool OperandIsAPointer = SrcGIOrNull->isOperandAPointer(i);
-      bool OperandIsAPointer =
-          (SrcGIOrNull->TheDef->getName() == "G_LOAD" && i == 0) ||
-          (SrcGIOrNull->TheDef->getName() == "G_STORE" && i == 1);
 
       // For G_INTRINSIC/G_INTRINSIC_W_SIDE_EFFECTS, the operand immediately
       // following the defs is an intrinsic ID.