diff --git a/base/compiler/optimize.jl b/base/compiler/optimize.jl
index b1cc75da70942..14b133b173fba 100644
--- a/base/compiler/optimize.jl
+++ b/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 || f === typeassert) && 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
diff --git a/base/compiler/tfuncs.jl b/base/compiler/tfuncs.jl
index 945b620abfa4e..afa3a36e8f595 100644
--- a/base/compiler/tfuncs.jl
+++ b/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 ||
diff --git a/base/iddict.jl b/base/iddict.jl
index 23ba65799a395..52b5d9e9de6c3 100644
--- a/base/iddict.jl
+++ b/base/iddict.jl
@@ -86,7 +86,7 @@ function get(d::IdDict{K,V}, @nospecialize(key), @nospecialize(default)) where {
     val === default ? default : val::V
 end
 function getindex(d::IdDict{K,V}, @nospecialize(key)) where {K, V}
-    val = get(d, key, secret_table_token)
+    val = ccall(:jl_eqtable_get, Any, (Any, Any, Any), d.ht, key, secret_table_token)
     val === secret_table_token && throw(KeyError(key))
     return val::V
 end
@@ -137,7 +137,7 @@ copy(d::IdDict) = typeof(d)(d)
 get!(d::IdDict{K,V}, @nospecialize(key), @nospecialize(default)) where {K, V} = (d[key] = get(d, key, default))::V
 
 function get(default::Callable, d::IdDict{K,V}, @nospecialize(key)) where {K, V}
-    val = get(d, key, secret_table_token)
+    val = ccall(:jl_eqtable_get, Any, (Any, Any, Any), d.ht, key, secret_table_token)
     if val === secret_table_token
         val = default()
     end
@@ -145,7 +145,7 @@ function get(default::Callable, d::IdDict{K,V}, @nospecialize(key)) where {K, V}
 end
 
 function get!(default::Callable, d::IdDict{K,V}, @nospecialize(key)) where {K, V}
-    val = get(d, key, secret_table_token)
+    val = ccall(:jl_eqtable_get, Any, (Any, Any, Any), d.ht, key, secret_table_token)
     if val === secret_table_token
         val = default()
         setindex!(d, val, key)
diff --git a/doc/src/devdocs/inference.md b/doc/src/devdocs/inference.md
index e9974824aa651..e6f577a6995cb 100644
--- a/doc/src/devdocs/inference.md
+++ b/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