src/hotspot/share/asm/assembler.cpp

rev 53052 : [mq]: asm.patch

@@ -307,38 +307,7 @@
   }
   return NULL;
 }
 
 bool MacroAssembler::needs_explicit_null_check(intptr_t offset) {
-  // Exception handler checks the nmethod's implicit null checks table
-  // only when this method returns false.
-#ifdef AARCH64
-  // AArch64 addresses passed from the signal handler may have
-  // their top 8 bits zeroed. That affects the case where
-  // Shenandoah tries to load a Brooks pointer via a null oop.
-  const uintptr_t address_bits = (uintptr_t)0xfffffffffffful;
-#else
-  const uintptr_t address_bits = ~(uintptr_t)0;
-#endif
-#ifdef _LP64
-  if (UseCompressedOops && Universe::narrow_oop_base() != NULL) {
-    assert (Universe::heap() != NULL, "java heap should be initialized");
-    // The first page after heap_base is unmapped and
-    // the 'offset' is equal to [heap_base + offset] for
-    // narrow oop implicit null checks.
-    uintptr_t base = (uintptr_t)Universe::narrow_oop_base();
-    int adj = MIN2(0, UseShenandoahGC ? BrooksPointer::byte_offset() : 0);
-    if ((uintptr_t)((offset - adj) & address_bits) >= base) {
-      // Normalize offset for the next check.
-      offset = (intptr_t)(pointer_delta((void*)offset, (void*)base, 1));
-    }
-  }
-#endif
-
-  if (UseShenandoahGC) {
-    if ((offset & address_bits) == (BrooksPointer::byte_offset() & address_bits)) {
-      return false;
-    }
-  }
-
-  return offset < 0 || os::vm_page_size() <= offset;
+  return BarrierSet::barrier_set()->barrier_set_assembler()->needs_explicit_null_check(offset);
 }