From eb6267defe657c220dfa1f198f3656922000e0b7 Mon Sep 17 00:00:00 2001
From: ProgramSnail <purpurebacterium@yandex.ru>
Date: Thu, 14 Nov 2024 02:10:24 +0300
Subject: [PATCH] fixes, less allocations

---
 byterun/include/stack.h   | 46 ++++++++++++++++++++++++++++++++-------
 byterun/src/interpreter.c | 24 +++++++++++++-------
 2 files changed, 54 insertions(+), 16 deletions(-)

diff --git a/byterun/include/stack.h b/byterun/include/stack.h
index e6b9f0c6f..b58de8ac5 100644
--- a/byterun/include/stack.h
+++ b/byterun/include/stack.h
@@ -23,10 +23,7 @@ static inline bool s_is_empty() {
   return false;
 }
 
-static inline void **s_nth(aint n) {
-  if (n < 0) {
-    s_failure(&s, "can't access stack by negative index");
-  }
+static inline void **s_nth(size_t n) {
   if ((void **)__gc_stack_top + n >= s_top()) {
     s_failure(&s, "not enough elements in stack");
   }
@@ -99,6 +96,42 @@ static inline void s_popn(size_t n) {
   __gc_stack_top += n * sizeof(void *);
 }
 
+// ------ complex operations ------
+
+// for some reason does not work in sexp constructor, probably connected with gc
+// behaviour
+static inline void s_put_nth(size_t n, void *val) {
+  s_push_nil();
+  if ((void **)__gc_stack_top + n >= s_top()) {
+    s_failure(&s, "not enough elements in stack");
+  }
+  if (s.fp != NULL && (void **)__gc_stack_top + n >= f_locals(s.fp)) {
+    s_failure(&s, "not enough elements in function stack");
+  }
+
+  for (size_t i = 0; i < n; ++i) {
+    ((void **)__gc_stack_top)[i] = ((void **)__gc_stack_top)[i + 1];
+  }
+  ((void **)__gc_stack_top)[n] = val;
+}
+
+static inline void s_rotate_n(size_t n) {
+  s_push_nil();
+  if ((void **)__gc_stack_top + (aint)n - 1 >= s_top()) {
+    s_failure(&s, "not enough elements in stack");
+  }
+  if (s.fp != NULL && (void **)__gc_stack_top + (aint)n - 1 >= f_locals(s.fp)) {
+    s_failure(&s, "not enough elements in function stack");
+  }
+
+  void *buf = NULL;
+  for (size_t i = 0; 2 * i < n; ++i) {
+    buf = ((void **)__gc_stack_top)[n - i];
+    ((void **)__gc_stack_top)[n - i] = ((void **)__gc_stack_top)[i];
+    ((void **)__gc_stack_top)[i] = buf;
+  }
+}
+
 // ------ functions ------
 
 // |> param_0 ... param_n | frame[ ret rp prev_fp &params &locals &end
@@ -186,10 +219,7 @@ static inline void print_stack() {
 
 // --- category ---
 
-static inline void **var_by_category(enum VarCategory category, int id) {
-  if (id < 0) {
-    s_failure(&s, "can't read variable: negative id"); // %i", id);
-  }
+static inline void **var_by_category(enum VarCategory category, size_t id) {
   void **var = NULL;
   switch (category) {
   case VAR_GLOBAL:
diff --git a/byterun/src/interpreter.c b/byterun/src/interpreter.c
index 9ed9df2b5..c6d088235 100644
--- a/byterun/src/interpreter.c
+++ b/byterun/src/interpreter.c
@@ -156,12 +156,16 @@ void run(bytefile *bf, int argc, char **argv) {
                                 ? alloc((args_count + 1) * sizeof(void *))
                                 : buffer;
 
+        // s_put_nth(args_count, (void *)LtagHash((char *)name));
+
         for (size_t i = 1; i <= args_count; ++i) {
           opr_buffer[args_count - i] = s_pop();
         }
         opr_buffer[args_count] = (void *)LtagHash((char *)name);
 
         void *sexp = Bsexp((aint *)opr_buffer, BOX(args_count + 1));
+        // void *sexp = Bsexp((aint *)s_peek(), BOX(args_count + 1));
+        // s_popn(args_count + 1);
 
         s_push(sexp);
         break;
@@ -440,16 +444,20 @@ void run(bytefile *bf, int argc, char **argv) {
       case CMD_BUILTIN_Barray: { // CALL Barray %d
         size_t elem_count = ip_read_int(&s.ip);
 
-        void **opr_buffer = elem_count > BUFFER_SIZE
-                                ? alloc(elem_count * sizeof(void *))
-                                : buffer;
-        for (size_t i = 0; i < elem_count; ++i) {
-          opr_buffer[elem_count - i - 1] = s_pop();
-        }
+        // void **opr_buffer = elem_count > BUFFER_SIZE
+        //                         ? alloc(elem_count * sizeof(void *))
+        //                         : buffer;
+        // for (size_t i = 0; i < elem_count; ++i) {
+        //   opr_buffer[elem_count - i - 1] = s_pop();
+        // }
 
+        s_rotate_n(elem_count);
+        // void *array =
+        //     Barray((aint *)opr_buffer,
+        //            BOX(elem_count)); // NOTE: not shure if elems should be added
         void *array =
-            Barray((aint *)opr_buffer,
-                   BOX(elem_count)); // NOTE: not shure if elems should be added
+            Barray((aint *)s_peek(),
+                   BOX(elem_count));
         s_push(array);
         break;
       }