From 4be9ffda842c3d4d3810f107f38f5dc9a2f34da5 Mon Sep 17 00:00:00 2001
From: Zoltan Herczeg <zherczeg.u-szeged@partner.samsung.com>
Date: Fri, 17 Apr 2020 13:05:07 +0200
Subject: [PATCH] Use symbolic constants for code size checks. (#3682)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com
---
 jerry-core/parser/js/js-parser-internal.h | 12 ++++++
 jerry-core/parser/js/js-parser-util.c     | 47 +++++++++--------------
 jerry-core/parser/js/js-parser.c          | 15 ++------
 3 files changed, 34 insertions(+), 40 deletions(-)

diff --git a/jerry-core/parser/js/js-parser-internal.h b/jerry-core/parser/js/js-parser-internal.h
index 16c13f406..28aa0deb9 100644
--- a/jerry-core/parser/js/js-parser-internal.h
+++ b/jerry-core/parser/js/js-parser-internal.h
@@ -124,6 +124,18 @@ typedef enum
  */
 #define PARSER_FUNCTION_CLOSURE (PARSER_IS_FUNCTION | PARSER_IS_CLOSURE)
 
+#if PARSER_MAXIMUM_CODE_SIZE <= UINT16_MAX
+/**
+ * Maximum number of bytes for branch target.
+ */
+#define PARSER_MAX_BRANCH_LENGTH 2
+#else /* PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX */
+/**
+ * Maximum number of bytes for branch target.
+ */
+#define PARSER_MAX_BRANCH_LENGTH 3
+#endif /* PARSER_MAXIMUM_CODE_SIZE <= UINT16_MAX */
+
 #if ENABLED (JERRY_ES2015)
 /**
  * Offset between PARSER_CLASS_CONSTRUCTOR and ECMA_PARSE_CLASS_CONSTRUCTOR
diff --git a/jerry-core/parser/js/js-parser-util.c b/jerry-core/parser/js/js-parser-util.c
index 352656e5e..09140e0ba 100644
--- a/jerry-core/parser/js/js-parser-util.c
+++ b/jerry-core/parser/js/js-parser-util.c
@@ -566,11 +566,7 @@ parser_emit_cbc_forward_branch (parser_context_t *context_p, /**< context */
   }
 #endif /* ENABLED (JERRY_PARSER_DUMP_BYTE_CODE) */
 
-#if PARSER_MAXIMUM_CODE_SIZE <= 65535
-  opcode++;
-#else /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
-  PARSER_PLUS_EQUAL_U16 (opcode, 2);
-#endif /* PARSER_MAXIMUM_CODE_SIZE <= 65535 */
+  PARSER_PLUS_EQUAL_U16 (opcode, PARSER_MAX_BRANCH_LENGTH - 1);
 
   parser_emit_two_bytes (context_p, (uint8_t) opcode, 0);
   branch_p->page_p = context_p->byte_code.last_p;
@@ -578,13 +574,13 @@ parser_emit_cbc_forward_branch (parser_context_t *context_p, /**< context */
 
   context_p->byte_code_size += extra_byte_code_increase;
 
-#if PARSER_MAXIMUM_CODE_SIZE <= 65535
+#if PARSER_MAXIMUM_CODE_SIZE <= UINT16_MAX
   PARSER_APPEND_TO_BYTE_CODE (context_p, 0);
-  context_p->byte_code_size += 3;
-#else /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
+#else /* PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX */
   parser_emit_two_bytes (context_p, 0, 0);
-  context_p->byte_code_size += 4;
-#endif /* PARSER_MAXIMUM_CODE_SIZE <= 65535 */
+#endif /* PARSER_MAXIMUM_CODE_SIZE <= UINT16_MAX */
+
+  context_p->byte_code_size += PARSER_MAX_BRANCH_LENGTH + 1;
 
   if (context_p->stack_depth > context_p->stack_limit)
   {
@@ -681,35 +677,30 @@ parser_emit_cbc_backward_branch (parser_context_t *context_p, /**< context */
 #endif /* ENABLED (JERRY_PARSER_DUMP_BYTE_CODE) */
 
   context_p->byte_code_size += 2;
-#if PARSER_MAXIMUM_CODE_SIZE <= 65535
-  if (offset > 255)
+#if PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX
+  if (offset > UINT16_MAX)
   {
     opcode++;
     context_p->byte_code_size++;
   }
-#else /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
-  if (offset > 65535)
-  {
-    PARSER_PLUS_EQUAL_U16 (opcode, 2);
-    context_p->byte_code_size += 2;
-  }
-  else if (offset > 255)
+#endif /* PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX */
+
+  if (offset > UINT8_MAX)
   {
     opcode++;
     context_p->byte_code_size++;
   }
-#endif /* PARSER_MAXIMUM_CODE_SIZE <= 65535 */
 
   PARSER_APPEND_TO_BYTE_CODE (context_p, (uint8_t) opcode);
 
-#if PARSER_MAXIMUM_CODE_SIZE > 65535
-  if (offset > 65535)
+#if PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX
+  if (offset > UINT16_MAX)
   {
     PARSER_APPEND_TO_BYTE_CODE (context_p, offset >> 16);
   }
-#endif /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
+#endif /* PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX */
 
-  if (offset > 255)
+  if (offset > UINT8_MAX)
   {
     PARSER_APPEND_TO_BYTE_CODE (context_p, (offset >> 8) & 0xff);
   }
@@ -745,14 +736,14 @@ parser_set_branch_to_current_position (parser_context_t *context_p, /**< context
 
   JERRY_ASSERT (delta <= PARSER_MAXIMUM_CODE_SIZE);
 
-#if PARSER_MAXIMUM_CODE_SIZE <= 65535
+#if PARSER_MAXIMUM_CODE_SIZE <= UINT16_MAX
   page_p->bytes[offset++] = (uint8_t) (delta >> 8);
   if (offset >= PARSER_CBC_STREAM_PAGE_SIZE)
   {
     page_p = page_p->next_p;
     offset = 0;
   }
-#else /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
+#else /* PARSER_MAXIMUM_CODE_SIZE > UINT16_MAX */
   page_p->bytes[offset++] = (uint8_t) (delta >> 16);
   if (offset >= PARSER_CBC_STREAM_PAGE_SIZE)
   {
@@ -765,8 +756,8 @@ parser_set_branch_to_current_position (parser_context_t *context_p, /**< context
     page_p = page_p->next_p;
     offset = 0;
   }
-#endif /* PARSER_MAXIMUM_CODE_SIZE <= 65535 */
-  page_p->bytes[offset++] = delta & 0xff;
+#endif /* PARSER_MAXIMUM_CODE_SIZE <= UINT16_MAX */
+  page_p->bytes[offset] = delta & 0xff;
 } /* parser_set_branch_to_current_position */
 
 /**
diff --git a/jerry-core/parser/js/js-parser.c b/jerry-core/parser/js/js-parser.c
index 0b55643c5..8206dd87b 100644
--- a/jerry-core/parser/js/js-parser.c
+++ b/jerry-core/parser/js/js-parser.c
@@ -1087,11 +1087,6 @@ parser_post_processing (parser_context_t *context_p) /**< context */
     if (flags & CBC_HAS_BRANCH_ARG)
     {
       bool prefix_zero = true;
-#if PARSER_MAXIMUM_CODE_SIZE <= 65535
-      cbc_opcode_t jump_forward = CBC_JUMP_FORWARD_2;
-#else /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
-      cbc_opcode_t jump_forward = CBC_JUMP_FORWARD_3;
-#endif /* PARSER_MAXIMUM_CODE_SIZE <= 65535 */
 
       /* The leading zeroes are dropped from the stream.
        * Although dropping these zeroes for backward
@@ -1114,9 +1109,9 @@ parser_post_processing (parser_context_t *context_p) /**< context */
         PARSER_NEXT_BYTE (page_p, offset);
       }
 
-      if (last_opcode == jump_forward
+      if (last_opcode == (cbc_opcode_t) (CBC_JUMP_FORWARD + PARSER_MAX_BRANCH_LENGTH - 1)
           && prefix_zero
-          && page_p->bytes[offset] == CBC_BRANCH_OFFSET_LENGTH (jump_forward) + 1)
+          && page_p->bytes[offset] == PARSER_MAX_BRANCH_LENGTH + 1)
       {
         /* Uncoditional jumps which jump right after the instruction
          * are effectively NOPs. These jumps are removed from the
@@ -1345,11 +1340,7 @@ parser_post_processing (parser_context_t *context_p) /**< context */
     if (opcode == CBC_JUMP_FORWARD)
     {
       /* These opcodes are deleted from the stream. */
-#if PARSER_MAXIMUM_CODE_SIZE <= 65535
-      size_t counter = 3;
-#else /* PARSER_MAXIMUM_CODE_SIZE > 65535 */
-      size_t counter = 4;
-#endif /* PARSER_MAXIMUM_CODE_SIZE <= 65535 */
+      size_t counter = PARSER_MAX_BRANCH_LENGTH + 1;
 
       do
       {