8264419: Remove has_max_index argument from G1BlockOffsetTablePart::block_at_or_preceding

Reviewed-by: ayang, tschatzl

Author: Ivan Walulya

src/hotspot/share/gc/g1/g1BlockOffsetTable.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -142,11 +142,7 @@ class G1BlockOffsetTablePart {
   inline size_t block_size(const HeapWord* p) const;
 
   // Returns the address of a block whose start is at most "addr".
-  // If "has_max_index" is true, "assumes "max_index" is the last valid one
-  // in the array.
-  inline HeapWord* block_at_or_preceding(const void* addr,
-                                         bool has_max_index,
-                                         size_t max_index) const;
+  inline HeapWord* block_at_or_preceding(const void* addr) const;
 
   // "q" is a block boundary that is <= "addr"; "n" is the address of the
   // next block (or the end of the space.)  Return the address of the

src/hotspot/share/gc/g1/g1BlockOffsetTable.inline.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -33,7 +33,7 @@
 
 inline HeapWord* G1BlockOffsetTablePart::block_start(const void* addr) {
   if (addr >= _hr->bottom() && addr < _hr->end()) {
-    HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
+    HeapWord* q = block_at_or_preceding(addr);
     return forward_to_block_containing_addr(q, addr);
   } else {
     return NULL;
@@ -42,7 +42,7 @@ inline HeapWord* G1BlockOffsetTablePart::block_start(const void* addr) {
 
 inline HeapWord* G1BlockOffsetTablePart::block_start_const(const void* addr) const {
   if (addr >= _hr->bottom() && addr < _hr->end()) {
-    HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
+    HeapWord* q = block_at_or_preceding(addr);
     HeapWord* n = q + block_size(q);
     return forward_to_block_containing_addr_const(q, n, addr);
   } else {
@@ -110,18 +110,15 @@ inline size_t G1BlockOffsetTablePart::block_size(const HeapWord* p) const {
   return _hr->block_size(p);
 }
 
-inline HeapWord* G1BlockOffsetTablePart::block_at_or_preceding(const void* addr,
-                                                               bool has_max_index,
-                                                               size_t max_index) const {
+inline HeapWord* G1BlockOffsetTablePart::block_at_or_preceding(const void* addr) const {
   assert(_object_can_span || _bot->offset_array(_bot->index_for(_hr->bottom())) == 0,
          "Object crossed region boundary, found offset %u instead of 0",
          (uint) _bot->offset_array(_bot->index_for(_hr->bottom())));
   size_t index = _bot->index_for(addr);
   // We must make sure that the offset table entry we use is valid.  If
-  // "addr" is past the end, start at the last known one and go forward.
-  if (has_max_index) {
-    index = MIN2(index, max_index);
-  }
+  // "addr" is past the end, start at the last valid index.
+  index = MIN2(index, _next_offset_index - 1);
+
   HeapWord* q = _bot->address_for_index(index);
 
   uint offset = _bot->offset_array(index);  // Extend u_char to uint.