Merge pull request #21187 from JuliaLang/jb/fix20671

fix #20671, slowdown loading SIUnits

Author: JeffBezanson

src/subtype.c

@@ -1148,8 +1148,12 @@ static jl_value_t *intersect_var(jl_tvar_t *b, jl_value_t *a, jl_stenv_t *e, int
     jl_value_t *root=NULL; jl_savedenv_t se;
     if (param == 2) {
         jl_value_t *ub = R ? intersect_ufirst(a, bb->ub, e, d) : intersect_ufirst(bb->ub, a, e, d);
-        JL_GC_PUSH1(&ub);
-        if (!subtype_in_env(bb->lb, a, e)) {
+        JL_GC_PUSH2(&ub, &root);
+        save_env(e, &root, &se);
+        int issub = subtype_in_env(bb->lb, ub, e);
+        restore_env(e, root, &se);
+        free(se.buf);
+        if (!issub) {
             JL_GC_POP();
             return jl_bottom_type;
         }
@@ -1219,6 +1223,9 @@ static jl_value_t *intersect_var(jl_tvar_t *b, jl_value_t *a, jl_stenv_t *e, int
         }
         return ub;
     }
+    else if (bb->ub == bb->lb) {
+        return ub;
+    }
     root = NULL;
     JL_GC_PUSH2(&root, &ub);
     save_env(e, &root, &se);
@@ -1326,9 +1333,14 @@ static jl_value_t *finish_unionall(jl_value_t *res, jl_varbinding_t *vb, jl_sten
             }
         }
         else {
-            varval = root = (jl_value_t*)jl_new_typevar(vb->var->name, vb->lb, vb->ub);
-            res = jl_instantiate_unionall((jl_unionall_t*)res, root);
-            res = jl_new_struct(jl_unionall_type, (jl_tvar_t*)root, res);
+            if (vb->lb != vb->var->lb || vb->ub != vb->var->ub) {
+                varval = root = (jl_value_t*)jl_new_typevar(vb->var->name, vb->lb, vb->ub);
+                res = jl_instantiate_unionall((jl_unionall_t*)res, root);
+                res = jl_new_struct(jl_unionall_type, (jl_tvar_t*)root, res);
+            }
+            else {
+                varval = (jl_value_t*)vb->var;
+            }
         }
     }
 

test/subtype.jl

@@ -622,6 +622,10 @@ abstract type AbstractTriangular{T,S<:AbstractMatrix} <: AbstractMatrix{T} end
 struct UpperTriangular{T,S<:AbstractMatrix} <: AbstractTriangular{T,S} end
 struct UnitUpperTriangular{T,S<:AbstractMatrix} <: AbstractTriangular{T,S} end
 
+immutable SIQ20671{T<:Number,m,kg,s,A,K,mol,cd,rad,sr} <: Number
+    val::T
+end
+
 function test_intersection()
     @testintersect(Vector{Float64}, Vector{Union{Float64,Float32}}, Bottom)
 
@@ -887,6 +891,14 @@ function test_intersection()
     @testintersect(Pair{L,Tuple{L,Pair{L,HL}}} where {L,HL},
                    Pair{R,Tuple{Pair{R,HR},R}} where {R,HR},
                    Bottom)  # X == Pair{X,...} is not satisfiable
+
+    # issue #20671 --- this just took too long
+    @testintersect(Tuple{Type{SIQ20671{T, mT, kgT, sT, AT, KT, molT, cdT, radT, srT}},
+                         SIQ20671{S, mS, kgS, sS, AS, KS, molS, cdS, radS, srS}} where {T, mT, kgT, sT, AT, KT, molT, cdT, radT, srT,
+                                                                                        S, mS, kgS, sS, AS, KS, molS, cdS, radS, srS},
+                   Tuple{Type{T}, T} where T,
+                   Tuple{Type{SIQ20671{T,mS,kgS,sS,AS,KS,molS,cdS,radS,srS}},
+                         SIQ20671{T,mS,kgS,sS,AS,KS,molS,cdS,radS,srS}} where {T,mS,kgS,sS,AS,KS,molS,cdS,radS,srS})
 end
 
 function test_intersection_properties()