Merge bleeding edge into the GC branch up to 7948. The asserts

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
===================================================================
--- src/x64/assembler-x64.cc	(revision 7948)
+++ src/x64/assembler-x64.cc	(working copy)
@@ -458,6 +458,20 @@
     int last_imm32 = pos - (current + sizeof(int32_t));
     long_at_put(current, last_imm32);
   }
+  while (L->is_near_linked()) {
+    int fixup_pos = L->near_link_pos();
+    int offset_to_next =
+        static_cast<int>(*reinterpret_cast<int8_t*>(addr_at(fixup_pos)));
+    ASSERT(offset_to_next <= 0);
+    int disp = pos - (fixup_pos + sizeof(int8_t));
+    ASSERT(is_int8(disp));
+    set_byte_at(fixup_pos, disp);
+    if (offset_to_next < 0) {
+      L->link_to(fixup_pos + offset_to_next, Label::kNear);
+    } else {
+      L->UnuseNear();
+    }
+  }
   L->bind_to(pos);
 }
 
@@ -467,19 +481,6 @@
 }
 
 
-void Assembler::bind(NearLabel* L) {
-  ASSERT(!L->is_bound());
-  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::GrowBuffer() {
   ASSERT(buffer_overflow());
   if (!own_buffer_) FATAL("external code buffer is too small");
@@ -1214,7 +1215,7 @@
 }
 
 
-void Assembler::j(Condition cc, Label* L) {
+void Assembler::j(Condition cc, Label* L, Label::Distance distance) {
   if (cc == always) {
     jmp(L);
     return;
@@ -1238,6 +1239,17 @@
       emit(0x80 | cc);
       emitl(offs - long_size);
     }
+  } else if (distance == Label::kNear) {
+    // 0111 tttn #8-bit disp
+    emit(0x70 | cc);
+    byte disp = 0x00;
+    if (L->is_near_linked()) {
+      int offset = L->near_link_pos() - pc_offset();
+      ASSERT(is_int8(offset));
+      disp = static_cast<byte>(offset & 0xFF);
+    }
+    L->link_to(pc_offset(), Label::kNear);
+    emit(disp);
   } else if (L->is_linked()) {
     // 0000 1111 1000 tttn #32-bit disp.
     emit(0x0F);
@@ -1267,28 +1279,8 @@
 }
 
 
-void Assembler::j(Condition cc, NearLabel* L, Hint hint) {
+void Assembler::jmp(Label* L, Label::Distance distance) {
   EnsureSpace ensure_space(this);
-  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());
-  }
-}
-
-
-void Assembler::jmp(Label* L) {
-  EnsureSpace ensure_space(this);
   const int short_size = sizeof(int8_t);
   const int long_size = sizeof(int32_t);
   if (L->is_bound()) {
@@ -1303,7 +1295,17 @@
       emit(0xE9);
       emitl(offs - long_size);
     }
-  } else  if (L->is_linked()) {
+  } else if (distance == Label::kNear) {
+    emit(0xEB);
+    byte disp = 0x00;
+    if (L->is_near_linked()) {
+      int offset = L->near_link_pos() - pc_offset();
+      ASSERT(is_int8(offset));
+      disp = static_cast<byte>(offset & 0xFF);
+    }
+    L->link_to(pc_offset(), Label::kNear);
+    emit(disp);
+  } else if (L->is_linked()) {
     // 1110 1001 #32-bit disp.
     emit(0xE9);
     emitl(L->pos());
@@ -1327,24 +1329,6 @@
 }
 
 
-void Assembler::jmp(NearLabel* L) {
-  EnsureSpace ensure_space(this);
-  if (L->is_bound()) {
-    const int short_size = sizeof(int8_t);
-    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::jmp(Register target) {
   EnsureSpace ensure_space(this);
   // Opcode FF/4 r64.