some inlining cost model updates

- treat arrayset like arrayref
- higher cost for passing unknown things to builtins
- add small cost for forward branches
- add small cost for sizeof, nfields, isa, subtype
- remove `nkw` meta after it's consumed

Author: JeffBezanson

base/compiler/optimize.jl

@@ -315,17 +315,30 @@ function statement_cost(ex::Expr, line::Int, src::CodeInfo, sptypes::Vector{Any}
                 # tuple iteration/destructuring makes that impossible
                 # return plus_saturate(argcost, isknowntype(extyp) ? 1 : params.inline_nonleaf_penalty)
                 return 0
-            elseif (f === Main.Core.arrayref || f === Main.Core.const_arrayref) && length(ex.args) >= 3
+            elseif (f === Main.Core.arrayref || f === Main.Core.const_arrayref || f === Main.Core.arrayset) && length(ex.args) >= 3
                 atyp = argextype(ex.args[3], src, sptypes, slottypes)
                 return isknowntype(atyp) ? 4 : params.inline_nonleaf_penalty
+            elseif f === isa && isconstType(widenconst(argextype(ex.args[3], src, sptypes, slottypes)))
+                return 1
+            elseif f === typeof
+                return 1
             end
             fidx = find_tfunc(f)
             if fidx === nothing
-                # unknown/unhandled builtin or anonymous function
+                # unknown/unhandled builtin
                 # Use the generic cost of a direct function call
                 return 20
             end
-            return T_FFUNC_COST[fidx]
+            cost = T_FFUNC_COST[fidx]
+            if cost < 20
+                for i = 2:length(ex.args)
+                    argtyp = argextype(ex.args[i], src, sptypes, slottypes)
+                    if !(isknowntype(argtyp) || isType(argtyp))
+                        return 20
+                    end
+                end
+            end
+            return cost
         end
         return params.inline_nonleaf_penalty
     elseif head === :foreigncall || head === :invoke
@@ -366,7 +379,7 @@ function statement_cost(ex::Expr, line::Int, src::CodeInfo, sptypes::Vector{Any}
         # loops are generally always expensive
         # but assume that forward jumps are already counted for from
         # summing the cost of the not-taken branch
-        return target < line ? 40 : 0
+        return target < line ? 40 : 1
     end
     return 0
 end

base/compiler/tfuncs.jl

@@ -342,7 +342,7 @@ function sizeof_tfunc(@nospecialize(x),)
     isprimitivetype(x) && return _const_sizeof(x)
     return Int
 end
-add_tfunc(Core.sizeof, 1, 1, sizeof_tfunc, 0)
+add_tfunc(Core.sizeof, 1, 1, sizeof_tfunc, 1)
 function nfields_tfunc(@nospecialize(x))
     isa(x, Const) && return Const(nfields(x.val))
     isa(x, Conditional) && return Const(0)
@@ -354,7 +354,7 @@ function nfields_tfunc(@nospecialize(x))
     end
     return Int
 end
-add_tfunc(nfields, 1, 1, nfields_tfunc, 0)
+add_tfunc(nfields, 1, 1, nfields_tfunc, 1)
 add_tfunc(Core._expr, 1, INT_INF, (@nospecialize args...)->Expr, 100)
 function typevar_tfunc(@nospecialize(n), @nospecialize(lb_arg), @nospecialize(ub_arg))
     lb = Union{}
@@ -537,7 +537,7 @@ function isa_tfunc(@nospecialize(v), @nospecialize(tt))
     # TODO: handle non-leaftype(t) by testing against lower and upper bounds
     return Bool
 end
-add_tfunc(isa, 2, 2, isa_tfunc, 0)
+add_tfunc(isa, 2, 2, isa_tfunc, 1)
 
 function subtype_tfunc(@nospecialize(a), @nospecialize(b))
     a, isexact_a = instanceof_tfunc(a)
@@ -555,7 +555,7 @@ function subtype_tfunc(@nospecialize(a), @nospecialize(b))
     end
     return Bool
 end
-add_tfunc(<:, 2, 2, subtype_tfunc, 0)
+add_tfunc(<:, 2, 2, subtype_tfunc, 1)
 
 is_dt_const_field(fld::Int) = (
      fld == DATATYPE_NAME_FIELDINDEX ||

doc/src/devdocs/inference.md

@@ -124,7 +124,7 @@ cst = map(cost, ci.code)
   1
   1
   1
-  0
+  1
   0
   0
   ⋮
@@ -133,7 +133,7 @@ cst = map(cost, ci.code)
   0
   0
   1
-  0
+  1
   0
   0
   0

src/method.c

@@ -566,6 +566,7 @@ static void jl_method_set_source(jl_method_t *m, jl_code_info_t *src)
             }
             else if (nargs == 2 && jl_exprarg(st, 0) == (jl_value_t*)jl_symbol("nkw")) {
                 m->nkw = jl_unbox_long(jl_exprarg(st, 1));
+                st = jl_nothing;
             }
         }
         else {