[TableGen][GlobalISel] Emit Comment with MatchTable Size (#74701)

Author: Pierre-vh

llvm/test/TableGen/GlobalISelCombinerEmitter/match-table.td

@@ -251,6 +251,6 @@ def MyCombiner: GICombiner<"GenMyCombiner", [
 // CHECK-NEXT:     GIM_Reject,
 // CHECK-NEXT:     // Label 6: @267
 // CHECK-NEXT:     GIM_Reject,
-// CHECK-NEXT:     };
+// CHECK-NEXT:     }; // Size: 2144 bytes
 // CHECK-NEXT:   return MatchTable0;
 // CHECK-NEXT: }

llvm/test/TableGen/GlobalISelEmitter.td

@@ -517,7 +517,7 @@ def : Pat<(frag GPR32:$src1, complex:$src2, complex:$src3),
 // R00O-NEXT:  GIM_Reject,
 // R00O:       // Label [[DEFAULT_NUM]]: @[[DEFAULT]]
 // R00O-NEXT:  GIM_Reject,
-// R00O-NEXT:  };
+// R00O-NEXT:  }; // Size: 9784 bytes
 
 def INSNBOB : I<(outs GPR32:$dst), (ins GPR32:$src1, GPR32:$src2, GPR32:$src3, GPR32:$src4),
                  [(set GPR32:$dst,
@@ -1169,5 +1169,5 @@ def BR : I<(outs), (ins unknown:$target),
             [(br bb:$target)]>;
 
 // NOOPT-NEXT:    GIM_Reject,
-// NOOPT-NEXT:  };
+// NOOPT-NEXT:  }; // Size: 11160 bytes
 // NOOPT-NEXT:  return MatchTable0;

llvm/utils/TableGen/GlobalISelMatchTable.cpp

@@ -243,7 +243,7 @@ void MatchTable::emitDeclaration(raw_ostream &OS) const {
     if (I->Flags & MatchTableRecord::MTRF_Outdent)
       Indentation -= 2;
   }
-  OS << "};\n";
+  OS << "}; // Size: " << (CurrentSize * 8) << " bytes\n";
 }
 
 MatchTable MatchTable::buildTable(ArrayRef<Matcher *> Rules, bool WithCoverage,