8325551: Remove unused obj_is_alive and block_start in Space

Reviewed-by: stefank

src/hotspot/share/gc/shared/space.cpp

@@ -140,11 +140,6 @@ void ContiguousSpace::verify() const {
   guarantee(p == top(), "end of last object must match end of space");
 }
 
-bool Space::obj_is_alive(const HeapWord* p) const {
-  assert (block_is_obj(p), "The address should point to an object");
-  return true;
-}
-
 void ContiguousSpace::object_iterate(ObjectClosure* blk) {
   HeapWord* addr = bottom();
   while (addr < top()) {

src/hotspot/share/gc/shared/space.hpp

@@ -141,25 +141,11 @@ class Space: public CHeapObj<mtGC> {
   // object or a non-object.  If "p" is not in the space, return null.
   virtual HeapWord* block_start_const(const void* p) const = 0;
 
-  // The non-const version may have benevolent side effects on the data
-  // structure supporting these calls, possibly speeding up future calls.
-  // The default implementation, however, is simply to call the const
-  // version.
-  HeapWord* block_start(const void* p);
-
   // Requires "addr" to be the start of a chunk, and returns its size.
   // "addr + size" is required to be the start of a new chunk, or the end
   // of the active area of the heap.
   virtual size_t block_size(const HeapWord* addr) const = 0;
 
-  // Requires "addr" to be the start of a block, and returns "TRUE" iff
-  // the block is an object.
-  virtual bool block_is_obj(const HeapWord* addr) const = 0;
-
-  // Requires "addr" to be the start of a block, and returns "TRUE" iff
-  // the block is an object and the object is alive.
-  bool obj_is_alive(const HeapWord* addr) const;
-
   // Allocation (return null if full).  Assumes the caller has established
   // mutually exclusive access to the space.
   virtual HeapWord* allocate(size_t word_size) = 0;
@@ -281,8 +267,6 @@ protected:
   // Very inefficient implementation.
   HeapWord* block_start_const(const void* p) const override;
   size_t block_size(const HeapWord* p) const override;
-  // If a block is in the allocated area, it is an object.
-  bool block_is_obj(const HeapWord* p) const override { return p < top(); }
 
   // Addresses for inlined allocation
   HeapWord** top_addr() { return &_top; }

src/hotspot/share/gc/shared/space.inline.hpp

@@ -34,10 +34,6 @@
 #include "runtime/prefetch.inline.hpp"
 #include "runtime/safepoint.hpp"
 
-inline HeapWord* Space::block_start(const void* p) {
-  return block_start_const(p);
-}
-
 #if INCLUDE_SERIALGC
 inline HeapWord* TenuredSpace::allocate(size_t size) {
   HeapWord* res = ContiguousSpace::allocate(size);