cache closures with no upvalues

1 files changed, 19 insertions, 8 deletions

diff --git a/pez.c b/pez.c
index 93b9354..19d53ce 100644
--- a/pez.c
+++ b/pez.c
@@ -76,7 +76,10 @@ typedef struct Proto {
     const char *file;
     const uint8_t *code;
     const Val *con;
-    struct cmupval *upval;
+    union {
+        struct cmupval *upval;
+        struct Fn *fn0; /* closures with 0 upvalues are cached */
+    };
     char name[];
 } Proto;
 
@@ -471,7 +474,9 @@ delproto(PezContext *cx, Proto *pr)
 {
     cxfree(cx, (void *)pr->code, pr->ncode);
     cxfree(cx, (void *)pr->con, pr->ncon * sizeof(Val));
-    cxfree(cx, (void *)pr->upval, pr->nupval * sizeof(struct cmupval));
+    if (pr->nupval) {
+        cxfree(cx, (void *)pr->upval, pr->nupval * sizeof(struct cmupval));
+    }
 }
 
 static void
@@ -503,7 +508,11 @@ sizeoffn(Fn *fn)
 static Fn *
 newfn(PezContext *cx, Proto *pr, Val *args, Val *locals, Fn *parent)
 {
-    Fn *fn = newobj(cx, PEZ_TFn, sizeof *fn + pr->nupval * sizeof(struct Upval *));
+    Fn *fn;
+    if (pr->nupval == 0 && pr->fn0) {
+        return pr->fn0;
+    }
+    fn = newobj(cx, PEZ_TFn, sizeof *fn + pr->nupval * sizeof(struct Upval *));
     if (fn) {
         TRY(push(cx, box_obj(fn))); // gc keep
         fn->proto = pr;
@@ -537,6 +546,9 @@ newfn(PezContext *cx, Proto *pr, Val *args, Val *locals, Fn *parent)
         }
         pop(cx);
     }
+    if (pr->nupval == 0) {
+        pr->fn0 = fn;
+    }
     return fn;
 }
 
@@ -1979,7 +1991,7 @@ f_arrayfill(PezContext *cx, int argc)
     n = unbox_num(cx->stktop[-2]);
     if (!isnum(cx->stktop[-2]) || n < 0 || fixtrunc(n) != n) {
         pez_error(cx, "array#fill", "argument #1 should be positive integer");
-        return 0;        
+        return 0;
     }
     TRY(arr = newarr(cx, fixtoint(n)));
     arr->len = fixtoint(n);
@@ -2054,10 +2066,9 @@ fincompfn(Comp *cm)
     pr->ncode = cm->code.len;
     pr->con = con;
     pr->ncon = cm->con.len;
-    pr->upval = cxalloc(cm->cx, cm->fenv.nupval * sizeof *pr->upval);
-    pr->nupval = cm->fenv.nupval;
-    // fprintf(stderr, "fini %s %d\n", pr->name, pr->nupval);
-    if (pr->upval) {
+    pr->upval = NULL;
+    if ((pr->nupval = cm->fenv.nupval) != 0) {
+        pr->upval = cxalloc(cm->cx, cm->fenv.nupval * sizeof *pr->upval);
         memcpy(pr->upval, cm->fenv.upvals, pr->nupval * sizeof(struct cmupval));
     }
     memset(&cm->code, 0, sizeof cm->code);