8307058: Implementation of Generational ZGC

Co-authored-by: Stefan Karlsson <stefank@openjdk.org>
Co-authored-by: Erik Österlund <eosterlund@openjdk.org>
Co-authored-by: Axel Boldt-Christmas <aboldtch@openjdk.org>
Co-authored-by: Per Liden <pliden@openjdk.org>
Co-authored-by: Stefan Johansson <sjohanss@openjdk.org>
Co-authored-by: Albert Mingkun Yang <ayang@openjdk.org>
Co-authored-by: Erik Helin <ehelin@openjdk.org>
Co-authored-by: Roberto Castañeda Lozano <rcastanedalo@openjdk.org>
Co-authored-by: Nils Eliasson <neliasso@openjdk.org>
Co-authored-by: Martin Doerr <mdoerr@openjdk.org>
Co-authored-by: Leslie Zhai <lzhai@openjdk.org>
Co-authored-by: Fei Yang <fyang@openjdk.org>
Co-authored-by: Yadong Wang <yadongwang@openjdk.org>
Reviewed-by: eosterlund, aboldtch, rcastanedalo

make/hotspot/gensrc/GensrcAdlc.gmk

@@ -172,6 +172,8 @@ ifeq ($(call check-jvm-feature, compiler2), true)
 
   ifeq ($(call check-jvm-feature, zgc), true)
     AD_SRC_FILES += $(call uniq, $(wildcard $(foreach d, $(AD_SRC_ROOTS), \
+        $d/cpu/$(HOTSPOT_TARGET_CPU_ARCH)/gc/x/x_$(HOTSPOT_TARGET_CPU).ad \
+        $d/cpu/$(HOTSPOT_TARGET_CPU_ARCH)/gc/x/x_$(HOTSPOT_TARGET_CPU_ARCH).ad \
         $d/cpu/$(HOTSPOT_TARGET_CPU_ARCH)/gc/z/z_$(HOTSPOT_TARGET_CPU).ad \
         $d/cpu/$(HOTSPOT_TARGET_CPU_ARCH)/gc/z/z_$(HOTSPOT_TARGET_CPU_ARCH).ad \
       )))

make/hotspot/lib/JvmFeatures.gmk

@@ -149,6 +149,7 @@ endif
 ifneq ($(call check-jvm-feature, zgc), true)
   JVM_CFLAGS_FEATURES += -DINCLUDE_ZGC=0
   JVM_EXCLUDE_PATTERNS += gc/z
+  JVM_EXCLUDE_PATTERNS += gc/x
 endif
 
 ifneq ($(call check-jvm-feature, shenandoahgc), true)

src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp

@@ -1010,7 +1010,7 @@ void LIR_Assembler::mem2reg(LIR_Opr src, LIR_Opr dest, BasicType type, LIR_Patch
       __ decode_heap_oop(dest->as_register());
     }
 
-    if (!UseZGC) {
+    if (!(UseZGC && !ZGenerational)) {
       // Load barrier has not yet been applied, so ZGC can't verify the oop here
       __ verify_oop(dest->as_register());
     }

src/hotspot/cpu/aarch64/gc/shared/barrierSetNMethod_aarch64.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2023, 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
@@ -129,20 +129,14 @@ class NativeNMethodBarrier {
   }
 };
 
-// Store the instruction bitmask, bits and name for checking the barrier.
-struct CheckInsn {
-  uint32_t mask;
-  uint32_t bits;
-  const char *name;
-};
-
 // The first instruction of the nmethod entry barrier is an ldr (literal)
 // instruction. Verify that it's really there, so the offsets are not skewed.
 bool NativeNMethodBarrier::check_barrier(err_msg& msg) const {
   uint32_t* addr = (uint32_t*) instruction_address();
   uint32_t inst = *addr;
   if ((inst & 0xff000000) != 0x18000000) {
-    msg.print("Addr: " INTPTR_FORMAT " Code: 0x%x not an ldr", p2i(addr), inst);
+    msg.print("Nmethod entry barrier did not start with ldr (literal) as expected. "
+              "Addr: " PTR_FORMAT " Code: " UINT32_FORMAT, p2i(addr), inst);
     return false;
   }
   return true;