Storing byte code size in the byte code header. This reduces the

memory consumption, because the new allocator uses less memory if
the size as available when a block is freed. Snapshot generation
is also simplified.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

Author: zherczeg

jerry-core/ecma/base/ecma-globals.h

@@ -741,17 +741,11 @@ typedef uintptr_t ecma_external_pointer_t;
   */
 typedef struct
 {
-  uint16_t status_flags;            /**< various status flags */
+  uint16_t size;                    /**< real size >> MEM_ALIGNMENT_LOG */
+  uint16_t refs;                    /**< reference counter for the byte code */
+  uint16_t status_flags;            /**< various status flags. */
 } ecma_compiled_code_t;
 
-/**
- * Shift value for byte code reference counting.
- * The last 10 bit of the first uint16_t value
- * of compact byte code or regexp byte code
- * is reserved for reference counting.
- */
-#define ECMA_BYTECODE_REF_SHIFT 6
-
 /**
  * @}
  */

jerry-core/ecma/base/ecma-helpers.c

@@ -1316,12 +1316,12 @@ void
 ecma_bytecode_ref (ecma_compiled_code_t *bytecode_p) /**< byte code pointer */
 {
   /* Abort program if maximum reference number is reached. */
-  if ((bytecode_p->status_flags >> ECMA_BYTECODE_REF_SHIFT) >= 0x3ff)
+  if (bytecode_p->refs >= UINT16_MAX)
   {
     jerry_fatal (ERR_REF_COUNT_LIMIT);
   }
 
-  bytecode_p->status_flags = (uint16_t) (bytecode_p->status_flags + (1u << ECMA_BYTECODE_REF_SHIFT));
+  bytecode_p->refs++;
 } /* ecma_bytecode_ref */
 
 /**
@@ -1331,11 +1331,11 @@ ecma_bytecode_ref (ecma_compiled_code_t *bytecode_p) /**< byte code pointer */
 void
 ecma_bytecode_deref (ecma_compiled_code_t *bytecode_p) /**< byte code pointer */
 {
-  JERRY_ASSERT ((bytecode_p->status_flags >> ECMA_BYTECODE_REF_SHIFT) > 0);
+  JERRY_ASSERT (bytecode_p->refs > 0);
 
-  bytecode_p->status_flags = (uint16_t) (bytecode_p->status_flags - (1u << ECMA_BYTECODE_REF_SHIFT));
+  bytecode_p->refs--;
 
-  if (bytecode_p->status_flags >= (1u << ECMA_BYTECODE_REF_SHIFT))
+  if (bytecode_p->refs > 0)
   {
     /* Non-zero reference counter. */
     return;
@@ -1388,7 +1388,8 @@ ecma_bytecode_deref (ecma_compiled_code_t *bytecode_p) /**< byte code pointer */
 #endif /* !CONFIG_ECMA_COMPACT_PROFILE_DISABLE_REGEXP_BUILTIN */
   }
 
-  mem_heap_free_block_size_stored (bytecode_p);
+  mem_heap_free_block (bytecode_p,
+                       ((size_t) bytecode_p->size) << MEM_ALIGNMENT_LOG);
 } /* ecma_bytecode_deref */
 
 /**

jerry-core/jerry-snapshot.h

@@ -24,27 +24,17 @@
  */
 typedef struct
 {
-  uint32_t last_compiled_code_offset; /**< offset of the last compiled code */
+  uint32_t version; /**< version number */
+  uint32_t lit_table_offset; /**< offset of the literal table */
   uint32_t lit_table_size; /**< size of literal table */
-  __extension__ uint32_t is_run_global : 1; /**< flag, indicating whether the snapshot
-                                             *   was dumped as 'Global scope'-mode code (true)
-                                             *   or as eval-mode code (false) */
+  uint8_t is_run_global; /**< flag, indicating whether the snapshot
+                           *   was dumped as 'Global scope'-mode code (true)
+                           *   or as eval-mode code (false) */
 } jerry_snapshot_header_t;
 
 /**
  * Jerry snapshot format version
  */
-#define JERRY_SNAPSHOT_VERSION (3u)
-
-#ifdef JERRY_ENABLE_SNAPSHOT_SAVE
-
-/* Snapshot support functions */
-
-extern bool snapshot_report_byte_code_compilation;
-
-extern void
-snapshot_add_compiled_code (ecma_compiled_code_t *, const uint8_t *, uint32_t);
-
-#endif /* JERRY_ENABLE_SNAPSHOT_SAVE */
+#define JERRY_SNAPSHOT_VERSION (4u)
 
 #endif /* !JERRY_SNAPSHOT_H */