Add support for near labels....

src/ia32/assembler-ia32.cc

Index: src/ia32/assembler-ia32.cc
===================================================================
--- src/ia32/assembler-ia32.cc	(revision 5449)
+++ src/ia32/assembler-ia32.cc	(working copy)
@@ -1511,40 +1511,27 @@
 }
 
 
-void Assembler::link_to(Label* L, Label* appendix) {
+void Assembler::bind(Label* L) {
   EnsureSpace ensure_space(this);
   last_pc_ = NULL;
-  if (appendix->is_linked()) {
-    if (L->is_linked()) {
-      // Append appendix to L's list.
-      Label p;
-      Label q = *L;
-      do {
-        p = q;
-        Displacement disp = disp_at(&q);
-        disp.next(&q);
-      } while (q.is_linked());
-      Displacement disp = disp_at(&p);
-      disp.link_to(appendix);
-      disp_at_put(&p, disp);
-      p.Unuse();  // to avoid assertion failure in ~Label
-    } else {
-      // L is empty, simply use appendix.
-      *L = *appendix;
-    }
-  }
-  appendix->Unuse();  // appendix should not be used anymore
+  ASSERT(!L->is_bound());  // label can only be bound once
+  bind_to(L, pc_offset());
 }
 
 
-void Assembler::bind(Label* L) {
-  EnsureSpace ensure_space(this);
+void Assembler::bind(NearLabel* L) {
+  ASSERT(!L->is_bound());
   last_pc_ = NULL;
-  ASSERT(!L->is_bound());  // label can only be bound once
-  bind_to(L, pc_offset());
+  while (L->unresolved_branches_ > 0) {
+    int branch_pos = L->unresolved_positions_[L->unresolved_branches_ - 1];
+    int disp = pc_offset() - branch_pos;
+    ASSERT(is_int8(disp));
+    set_byte_at(branch_pos - sizeof(int8_t), disp);
+    L->unresolved_branches_--;
+  }
+  L->bind_to(pc_offset());
 }
 
-
 void Assembler::call(Label* L) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
@@ -1641,7 +1628,25 @@
 }
 
 
+void Assembler::jmp(NearLabel* L) {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  if (L->is_bound()) {
+    const int short_size = 2;
+    int offs = L->pos() - pc_offset();
+    ASSERT(offs <= 0);
+    ASSERT(is_int8(offs - short_size));
+    // 1110 1011 #8-bit disp.
+    EMIT(0xEB);
+    EMIT((offs - short_size) & 0xFF);
+  } else {
+    EMIT(0xEB);
+    EMIT(0x00);      // The displacement will be resolved later.
+    L->link_to(pc_offset());
+  }
+}
 
+
 void Assembler::j(Condition cc, Label* L, Hint hint) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
@@ -1696,6 +1701,27 @@
 }
 
 
+void Assembler::j(Condition cc, NearLabel* L, Hint hint) {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  ASSERT(0 <= cc && cc < 16);
+  if (FLAG_emit_branch_hints && hint != no_hint) EMIT(hint);
+  if (L->is_bound()) {
+    const int short_size = 2;
+    int offs = L->pos() - pc_offset();
+    ASSERT(offs <= 0);
+    ASSERT(is_int8(offs - short_size));
+    // 0111 tttn #8-bit disp
+    EMIT(0x70 | cc);
+    EMIT((offs - short_size) & 0xFF);
+  } else {
+    EMIT(0x70 | cc);
+    EMIT(0x00);      // The displacement will be resolved later.
+    L->link_to(pc_offset());
+  }
+}
+
+
 // FPU instructions.
 
 void Assembler::fld(int i) {