Simplify frame logic.

3 files changed, 47 insertions, 85 deletions

diff --git a/execute.c b/execute.c
index 1c6c24a3..6fadc4ec 100644
--- a/execute.c
+++ b/execute.c
@@ -125,11 +125,11 @@ static struct closure make_closure(struct jq_state* jq, stack_ptr fridx, uint16_
   uint16_t level = *pc++;
   uint16_t idx = *pc++;
   fridx = frame_get_level(&jq->stk, fridx, level);
-  frame_ptr fr = frame_current(&jq->stk, fridx);
+  struct frame* fr = frame_current(&jq->stk, fridx);
   if (idx & ARG_NEWCLOSURE) {
     int subfn_idx = idx & ~ARG_NEWCLOSURE;
-    assert(subfn_idx < frame_self(fr)->bc->nsubfunctions);
-    struct closure cl = {frame_self(fr)->bc->subfunctions[subfn_idx],
+    assert(subfn_idx < fr->bc->nsubfunctions);
+    struct closure cl = {fr->bc->subfunctions[subfn_idx],
                          fridx};
     return cl;
   } else {
@@ -159,7 +159,7 @@ jv jq_next(jq_state *jq) {
     uint16_t opcode = *pc;
 
     if (jq->debug_trace_enabled) {
-      dump_operation(frame_current_bytecode(&jq->stk, jq->curr_frame), pc);
+      dump_operation(frame_current(&jq->stk, jq->curr_frame)->bc, pc);
       printf("\t");
       const struct opcode_description* opdesc = opcode_describe(opcode);
       stack_ptr param = 0;
@@ -196,7 +196,7 @@ jv jq_next(jq_state *jq) {
     default: assert(0 && "invalid instruction");
 
     case LOADK: {
-      jv v = jv_array_get(jv_copy(frame_current_bytecode(&jq->stk, jq->curr_frame)->constants), *pc++);
+      jv v = jv_array_get(jv_copy(frame_current(&jq->stk, jq->curr_frame)->bc->constants), *pc++);
       assert(jv_is_valid(v));
       jv_free(stack_pop(jq));
       stack_push(jq, v);
@@ -246,7 +246,7 @@ jv jq_next(jq_state *jq) {
       jv v = stack_pop(jq);
       uint16_t level = *pc++;
       uint16_t vidx = *pc++;
-      frame_ptr fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
+      struct frame* fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
       jv* var = frame_local_var(fp, vidx);
       assert(jv_get_kind(*var) == JV_KIND_ARRAY);
       *var = jv_array_append(*var, v);
@@ -278,7 +278,7 @@ jv jq_next(jq_state *jq) {
     case RANGE: {
       uint16_t level = *pc++;
       uint16_t v = *pc++;
-      frame_ptr fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
+      struct frame* fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
       jv* var = frame_local_var(fp, v);
       jv max = stack_pop(jq);
       if (jv_get_kind(*var) != JV_KIND_NUMBER ||
@@ -306,7 +306,7 @@ jv jq_next(jq_state *jq) {
     case LOADV: {
       uint16_t level = *pc++;
       uint16_t v = *pc++;
-      frame_ptr fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
+      struct frame* fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
       jv* var = frame_local_var(fp, v);
       if (jq->debug_trace_enabled) {
         printf("V%d = ", v);
@@ -322,7 +322,7 @@ jv jq_next(jq_state *jq) {
     case LOADVN: {
       uint16_t level = *pc++;
       uint16_t v = *pc++;
-      frame_ptr fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
+      struct frame* fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
       jv* var = frame_local_var(fp, v);
       if (jq->debug_trace_enabled) {
         printf("V%d = ", v);
@@ -338,7 +338,7 @@ jv jq_next(jq_state *jq) {
     case STOREV: {
       uint16_t level = *pc++;
       uint16_t v = *pc++;
-      frame_ptr fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
+      struct frame* fp = frame_current(&jq->stk, frame_get_level(&jq->stk, jq->curr_frame, level));
       jv* var = frame_local_var(fp, v);
       jv val = stack_pop(jq);
       if (jq->debug_trace_enabled) {
@@ -504,7 +504,7 @@ jv jq_next(jq_state *jq) {
       for (int i = 1; i < nargs; i++) {
         cfunc_input[i] = stack_pop(jq);
       }
-      struct cfunction* func = &frame_current_bytecode(&jq->stk, jq->curr_frame)->globals->cfunctions[*pc++];
+      struct cfunction* func = &frame_current(&jq->stk, jq->curr_frame)->bc->globals->cfunctions[*pc++];
       top = cfunction_invoke(func, cfunc_input);
       if (jv_is_valid(top)) {
         stack_push(jq, top);
@@ -525,22 +525,22 @@ jv jq_next(jq_state *jq) {
                                   retaddr, jq->stk_top);
       pc += 2;
 
-      frame_ptr new_frame = frame_current(&jq->stk, jq->curr_frame);
-      assert(nclosures == frame_self(new_frame)->bc->nclosures);
+      struct frame* new_frame = frame_current(&jq->stk, jq->curr_frame);
+      assert(nclosures == new_frame->bc->nclosures);
       for (int i=0; i<nclosures; i++) {
         *frame_closure_arg(new_frame, i) = make_closure(jq, old_frame, pc);
         pc += 2;
       }
 
-      pc = frame_current_bytecode(&jq->stk, jq->curr_frame)->code;
+      pc = frame_current(&jq->stk, jq->curr_frame)->bc->code;
       stack_push(jq, input);
       break;
     }
 
     case RET: {
       jv value = stack_pop(jq);
-      assert(jq->stk_top == frame_self(frame_current(&jq->stk, jq->curr_frame))->retdata);
-      uint16_t* retaddr = *frame_current_retaddr(&jq->stk, jq->curr_frame);
+      assert(jq->stk_top == frame_current(&jq->stk, jq->curr_frame)->retdata);
+      uint16_t* retaddr = frame_current(&jq->stk, jq->curr_frame)->retaddr;
       if (retaddr) {
         // function return
         pc = retaddr;
diff --git a/frame_layout.h b/frame_layout.h
index 0210c0c4..18a0a652 100644
--- a/frame_layout.h
+++ b/frame_layout.h
@@ -7,88 +7,65 @@ struct closure {
   stack_ptr env;
 };
 
-struct continuation {
+union frame_entry {
+  struct closure closure;
+  jv localvar;
+};
+
+struct frame {
   struct bytecode* bc;
   stack_ptr env;
   stack_ptr retdata;
   uint16_t* retaddr;
+  /* bc->nclosures closures followed by bc->nlocals local variables */
+  union frame_entry entries[0]; 
 };
 
-typedef union frame_elem {
-  struct continuation cont;
-  struct closure closure;
-  jv jsonval;
-} *frame_ptr;
-
-/*
- * Frame layout
- * fr[0] - FORKABLE_STACK_HEADER (next pointer)
- * fr[1] - self (used to store return addresses, etc)
- * fr[2...nclosures+2] - closure params
- * fr[nclosures+2..nclosures+nlocals+2] - local variables
- */
-
 static int frame_size(struct bytecode* bc) {
-  return sizeof(union frame_elem) * (bc->nclosures + bc->nlocals + 2);
-}
-
-static struct continuation* frame_self(frame_ptr fr) {
-  return &fr[1].cont;
+  return sizeof(struct frame) + sizeof(union frame_entry) * (bc->nclosures + bc->nlocals);
 }
 
-static struct closure* frame_closure_arg(frame_ptr fr, int closure) {
+static struct closure* frame_closure_arg(struct frame* fr, int closure) {
   assert(closure >= 0);
-  assert(closure < frame_self(fr)->bc->nclosures);
-  return &fr[2+closure].closure;
+  assert(closure < fr->bc->nclosures);
+  return &fr->entries[closure].closure;
 }
 
-static jv* frame_local_var(frame_ptr fr, int var) {
+static jv* frame_local_var(struct frame* fr, int var) {
   assert(var >= 0);
-  assert(var < frame_self(fr)->bc->nlocals);
-  return &fr[2 + frame_self(fr)->bc->nclosures + var].jsonval;
+  assert(var < fr->bc->nlocals);
+  return &fr->entries[fr->bc->nclosures + var].localvar;
 }
 
-
-static frame_ptr frame_current(struct stack* stk, stack_ptr idx) {
-  frame_ptr fp = stack_block(stk, idx);
+static struct frame* frame_current(struct stack* stk, stack_ptr idx) {
+  struct frame* fp = stack_block(stk, idx);
 
   stack_ptr next = *stack_block_next(stk, idx);
   if (next) {
-    frame_ptr fpnext = stack_block(stk, next);
-    struct bytecode* bc = frame_self(fpnext)->bc;
-    assert(frame_self(fp)->retaddr >= bc->code && frame_self(fp)->retaddr < bc->code + bc->codelen);
+    struct frame* fpnext = stack_block(stk, next);
+    struct bytecode* bc = fpnext->bc;
+    assert(fp->retaddr >= bc->code && fp->retaddr < bc->code + bc->codelen);
   } else {
-    assert(frame_self(fp)->retaddr == 0);
+    assert(fp->retaddr == 0);
   }
   return fp;
 }
 
-static struct bytecode* frame_current_bytecode(struct stack* stk, stack_ptr curr) {
-  return frame_self(frame_current(stk, curr))->bc;
-}
-static uint16_t** frame_current_retaddr(struct stack* stk, stack_ptr curr) {
-  return &frame_self(frame_current(stk, curr))->retaddr;
-}
-
-static stack_ptr frame_get_parent(struct stack* stk, stack_ptr fr) {
-  return frame_self(stack_block(stk, fr))->env;
-}
-
 static stack_ptr frame_get_level(struct stack* stk, stack_ptr fr, int level) {
   for (int i=0; i<level; i++) {
-    fr = frame_get_parent(stk, fr);
+    struct frame* fp = stack_block(stk, fr);
+    fr = fp->env;
   }
   return fr;
 }
 
 static stack_ptr frame_push(struct stack* stk, stack_ptr curr, struct closure cl, uint16_t* retaddr, stack_ptr datastk) {
   stack_ptr fpidx = stack_push_block(stk, curr, frame_size(cl.bc));
-  frame_ptr fp = stack_block(stk, fpidx);
-  struct continuation* cc = frame_self(fp);
-  cc->bc = cl.bc;
-  cc->env = cl.env;
-  cc->retdata = datastk;
-  cc->retaddr = retaddr;
+  struct frame* fp = stack_block(stk, fpidx);
+  fp->bc = cl.bc;
+  fp->env = cl.env;
+  fp->retdata = datastk;
+  fp->retaddr = retaddr;
   for (int i=0; i<cl.bc->nlocals; i++) {
     *frame_local_var(fp, i) = jv_invalid();
   }
@@ -96,14 +73,14 @@ static stack_ptr frame_push(struct stack* stk, stack_ptr curr, struct closure cl
 }
 
 static stack_ptr frame_pop(struct stack* stk, stack_ptr curr) {
-  frame_ptr fp = frame_current(stk, curr);
+  struct frame* fp = frame_current(stk, curr);
   if (stack_pop_will_free(stk, curr)) {
-    int nlocals = frame_self(fp)->bc->nlocals;
+    int nlocals = fp->bc->nlocals;
     for (int i=0; i<nlocals; i++) {
       jv_free(*frame_local_var(fp, i));
     }
   }
-  return stack_pop_block(stk, curr, frame_size(frame_self(fp)->bc));
+  return stack_pop_block(stk, curr, frame_size(fp->bc));
 }
 
 #endif
diff --git a/newstack.h b/newstack.h
index 267ae768..0da9dc5d 100644
--- a/newstack.h
+++ b/newstack.h
@@ -86,18 +86,3 @@ stack_ptr stack_pop_block(struct stack* s, stack_ptr p, size_t sz) {
   }
   return r;
 }
-
-#if 0
-int main() {
-  stack s;
-  stack_init(&s);
-  stack_ptr top = 0;
-  top = stack_push_block(&s, top, sizeof(double));
-  double* d1 = stack_block(&s, top);
-  *d1 = 42;
-  top = stack_push_block(&s, top, sizeof(double));
-  double* d2 = stack_block(&s, top);
-  *d2 = 33;
-
-}
-#endif