[TableGen][InstrInfoEmitter] Count sub-operands on def operands

- If a def operand includes multiple sub-operands, count them when
  generating instr info.
- Found issues in x86 and sparc backends, where memory operands of
  store or store-like instructions are wrongly placed in the output
  list.

Reviewers: jayfoad, arsenm, Pierre-vh

Reviewed By: arsenm

Pull Request: https://github.com/llvm/llvm-project/pull/88972

llvm/test/TableGen/def-multiple-operands.td

@@ -0,0 +1,37 @@
+// RUN: llvm-tblgen -gen-instr-info -I %p/../../include %s | FileCheck %s
+
+include "llvm/Target/Target.td"
+
+def archInstrInfo : InstrInfo {}
+
+def arch : Target {
+  let InstructionSet = archInstrInfo;
+}
+
+def R0 : Register<"r0">;
+def P0 : Register<"p0">;
+def R32 : RegisterClass<"MyNS", [i32], 0, (add R0)>;
+def P1 : RegisterClass<"MyNS", [i1], 0, (add P0)>;
+
+def Reg3Opnd : Operand<OtherVT> {
+  let MIOperandInfo = (ops R32, R32, P1);
+}
+
+// The following checks verify that 'MCInstrDesc' entry for 'InstA' has the
+// expected 'NumOperands' and 'NumDefs', i.e. 'InstA' should have 3 defs out of
+// 4 operands.
+
+// CHECK: archInstrTable {{.* = \{}}
+// CHECK: {{\{}}
+// CHECK: {{\{}} [[ID:[0-9]+]], 4, 3, 13, {{.+\}, \/\/}}
+// CHECK-SAME: Inst #[[ID]] = InstA
+def InstA : Instruction {
+  let Namespace = "MyNS";
+  let Size = 13;
+  // InstA should have 3 defs out of 4 operands.
+  let OutOperandList = (outs Reg3Opnd:$dst);
+  let InOperandList = (ins i32imm:$c);
+  field bits<8> Inst;
+  field bits<8> SoftFail = 0;
+  let hasSideEffects = false;
+}

llvm/utils/TableGen/InstrInfoEmitter.cpp

@@ -1181,9 +1181,15 @@ void InstrInfoEmitter::emitRecord(
     // Each logical operand can be multiple MI operands.
     MinOperands =
         Inst.Operands.back().MIOperandNo + Inst.Operands.back().MINumOperands;
+  // Even the logical output operand may be multiple MI operands.
+  int DefOperands = 0;
+  if (Inst.Operands.NumDefs) {
+    auto &Opnd = Inst.Operands[Inst.Operands.NumDefs - 1];
+    DefOperands = Opnd.MIOperandNo + Opnd.MINumOperands;
+  }
 
   OS << "    { ";
-  OS << Num << ",\t" << MinOperands << ",\t" << Inst.Operands.NumDefs << ",\t"
+  OS << Num << ",\t" << MinOperands << ",\t" << DefOperands << ",\t"
      << Inst.TheDef->getValueAsInt("Size") << ",\t"
      << SchedModels.getSchedClassIdx(Inst) << ",\t";