diff --git a/src/hotspot/cpu/aarch64/c1_Defs_aarch64.hpp b/src/hotspot/cpu/aarch64/c1_Defs_aarch64.hpp
index 9470caae9fe..5f65ef5f043 100644
--- a/src/hotspot/cpu/aarch64/c1_Defs_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/c1_Defs_aarch64.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -41,16 +41,17 @@ enum {
 
 // registers
 enum {
+  pd_nof_available_regs = 32,
   pd_nof_cpu_regs_frame_map = Register::number_of_registers,       // number of GP registers used during code emission
   pd_nof_fpu_regs_frame_map = FloatRegister::number_of_registers,  // number of FP registers used during code emission
 
-  pd_nof_caller_save_cpu_regs_frame_map = 19 - 2 /* rscratch1 and rscratch2 */ R18_RESERVED_ONLY(- 1),  // number of registers killed by calls
+  pd_nof_caller_save_cpu_regs_frame_map = pd_nof_available_regs,  // number of registers killed by calls
   pd_nof_caller_save_fpu_regs_frame_map = 32,  // number of registers killed by calls
 
-  pd_first_callee_saved_reg = 19 - 2 /* rscratch1 and rscratch2 */ R18_RESERVED_ONLY(- 1),
-  pd_last_callee_saved_reg = 26 - 2 /* rscratch1 and rscratch2 */ R18_RESERVED_ONLY(- 1),
+  pd_first_callee_saved_reg = pd_nof_available_regs - 1,
+  pd_last_callee_saved_reg = pd_first_callee_saved_reg - 1, // in fact, no callee saved regs
 
-  pd_last_allocatable_cpu_reg = 16 R18_RESERVED_ONLY(- 1),
+  pd_last_allocatable_cpu_reg = pd_nof_available_regs - 1,
 
   pd_nof_cpu_regs_reg_alloc
     = pd_last_allocatable_cpu_reg + 1,  // number of registers that are visible to register allocator
@@ -60,9 +61,9 @@ enum {
   pd_nof_fpu_regs_linearscan = pd_nof_fpu_regs_frame_map, // number of registers visible to linear scan
   pd_nof_xmm_regs_linearscan = 0,  // don't have vector registers
   pd_first_cpu_reg = 0,
-  pd_last_cpu_reg = 16 R18_RESERVED_ONLY(- 1),
+  pd_last_cpu_reg = pd_nof_available_regs - 1,
   pd_first_byte_reg = 0,
-  pd_last_byte_reg = 16 R18_RESERVED_ONLY(- 1),
+  pd_last_byte_reg = pd_last_cpu_reg,
   pd_first_fpu_reg = pd_nof_cpu_regs_frame_map,
   pd_last_fpu_reg =  pd_first_fpu_reg + 31,
 
diff --git a/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.cpp b/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.cpp
index 051b2ff47c1..9d30092b45a 100644
--- a/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.cpp
@@ -193,9 +193,26 @@ void FrameMap::initialize() {
   map_register(i, r25); r25_opr = LIR_OprFact::single_cpu(i); i++;
   map_register(i, r26); r26_opr = LIR_OprFact::single_cpu(i); i++;
 
-  map_register(i, r27); r27_opr = LIR_OprFact::single_cpu(i); i++; // rheapbase
+  // r27 is allocated conditionally. With compressed oops it holds
+  // the heapbase value and is not visible to the allocator.
+  bool preserve_rheapbase = i >= nof_caller_save_cpu_regs();
+  if (!preserve_rheapbase) {
+    map_register(i, r27); r27_opr = LIR_OprFact::single_cpu(i); i++; // rheapbase
+  }
+
+  if(!PreserveFramePointer) {
+    map_register(i, r29); r29_opr = LIR_OprFact::single_cpu(i); i++;
+  }
+
+  // The unallocatable registers are at the end
+
+  if (preserve_rheapbase) {
+    map_register(i, r27); r27_opr = LIR_OprFact::single_cpu(i); i++; // rheapbase
+  }
   map_register(i, r28); r28_opr = LIR_OprFact::single_cpu(i); i++; // rthread
-  map_register(i, r29); r29_opr = LIR_OprFact::single_cpu(i); i++; // rfp
+  if(PreserveFramePointer) {
+    map_register(i, r29); r29_opr = LIR_OprFact::single_cpu(i); i++; // rfp
+  }
   map_register(i, r30); r30_opr = LIR_OprFact::single_cpu(i); i++; // lr
   map_register(i, r31_sp); sp_opr = LIR_OprFact::single_cpu(i); i++; // sp
   map_register(i, r8); r8_opr = LIR_OprFact::single_cpu(i); i++;   // rscratch1
@@ -239,6 +256,19 @@ void FrameMap::initialize() {
   _caller_save_cpu_regs[16] = r18_opr;
 #endif
 
+  _caller_save_cpu_regs[17 R18_RESERVED_ONLY(-1)] = r19_opr;
+  _caller_save_cpu_regs[18 R18_RESERVED_ONLY(-1)] = r20_opr;
+  _caller_save_cpu_regs[19 R18_RESERVED_ONLY(-1)] = r21_opr;
+  _caller_save_cpu_regs[20 R18_RESERVED_ONLY(-1)] = r22_opr;
+  _caller_save_cpu_regs[21 R18_RESERVED_ONLY(-1)] = r23_opr;
+  _caller_save_cpu_regs[22 R18_RESERVED_ONLY(-1)] = r24_opr;
+  _caller_save_cpu_regs[23 R18_RESERVED_ONLY(-1)] = r25_opr;
+  _caller_save_cpu_regs[24 R18_RESERVED_ONLY(-1)] = r26_opr;
+
+  if (nof_caller_save_cpu_regs() > 25 R18_RESERVED_ONLY(-1)) {
+    _caller_save_cpu_regs[25 R18_RESERVED_ONLY(-1)] = r27_opr;
+  }
+
   for (int i = 0; i < 8; i++) {
     _caller_save_fpu_regs[i] = LIR_OprFact::single_fpu(i);
   }
diff --git a/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.hpp b/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.hpp
index 3ec3ce1f679..4d783418429 100644
--- a/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/c1_FrameMap_aarch64.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -140,8 +140,27 @@
   static bool is_caller_save_register (LIR_Opr opr) { return true; }
   static bool is_caller_save_register (Register r) { return true; }
 
-  static int nof_caller_save_cpu_regs() { return pd_nof_caller_save_cpu_regs_frame_map; }
-  static int last_cpu_reg()             { return pd_last_cpu_reg;  }
-  static int last_byte_reg()            { return pd_last_byte_reg; }
+  static int adjust_reg_range(int range, bool exclude_fp = true) {
+    // r27 is not allocatable when compressed oops is on and heapbase is not
+    // zero, compressed klass pointers doesn't use r27 after JDK-8234794
+    if (UseCompressedOops && (CompressedOops::base() != nullptr)) {
+      range -= 1;
+    }
+
+    // r29 is not allocatable when PreserveFramePointer is on,
+    // but fp saving is handled in MacroAssembler::build_frame()/remove_frame()
+    if (exclude_fp) {
+      range -= 1;
+    }
+
+    // rscratch registers r8, r9
+    // r28=rthread, r30=lr, r31=sp
+    // r18 on masOS/Windows
+    return range - 5 R18_RESERVED_ONLY(-1);
+  }
+
+  static int nof_caller_save_cpu_regs() { return adjust_reg_range(pd_nof_caller_save_cpu_regs_frame_map);  }
+  static int last_cpu_reg()             { return adjust_reg_range(pd_last_cpu_reg, PreserveFramePointer);  }
+  static int last_byte_reg()            { return adjust_reg_range(pd_last_byte_reg, PreserveFramePointer); }
 
 #endif // CPU_AARCH64_C1_FRAMEMAP_AARCH64_HPP
diff --git a/src/hotspot/cpu/aarch64/c1_LinearScan_aarch64.hpp b/src/hotspot/cpu/aarch64/c1_LinearScan_aarch64.hpp
index 01a4d27532a..4062adf4154 100644
--- a/src/hotspot/cpu/aarch64/c1_LinearScan_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/c1_LinearScan_aarch64.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2025, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -41,9 +41,9 @@ inline bool LinearScan::requires_adjacent_regs(BasicType type) {
 
 inline bool LinearScan::is_caller_save(int assigned_reg) {
   assert(assigned_reg >= 0 && assigned_reg < nof_regs, "should call this only for registers");
-  if (assigned_reg < pd_first_callee_saved_reg)
+  if (assigned_reg < FrameMap::nof_caller_save_cpu_regs())
     return true;
-  if (assigned_reg > pd_last_callee_saved_reg && assigned_reg < pd_first_callee_saved_fpu_reg)
+  if (assigned_reg >= pd_first_fpu_reg && assigned_reg < pd_first_callee_saved_fpu_reg)
     return true;
   if (assigned_reg > pd_last_callee_saved_fpu_reg && assigned_reg < pd_last_fpu_reg)
     return true;
@@ -66,7 +66,7 @@ inline bool LinearScanWalker::pd_init_regs_for_alloc(Interval* cur) {
     return true;
   } else if (cur->type() == T_INT || cur->type() == T_LONG || cur->type() == T_OBJECT || cur->type() == T_ADDRESS || cur->type() == T_METADATA) {
     _first_reg = pd_first_cpu_reg;
-    _last_reg = pd_last_allocatable_cpu_reg;
+    _last_reg = FrameMap::last_cpu_reg();
     return true;
   }
   return false;
diff --git a/src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp b/src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp
index 7082b4110cd..063918ee20b 100644
--- a/src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp
@@ -257,15 +257,18 @@ static OopMap* generate_oop_map(StubAssembler* sasm, bool save_fpu_registers) {
   int frame_size_in_slots = frame_size_in_bytes / sizeof(jint);
   OopMap* oop_map = new OopMap(frame_size_in_slots, 0);
 
-  for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
-    Register r = as_Register(i);
-    if (r == rthread || (i <= 18 && i != rscratch1->encoding() && i != rscratch2->encoding())) {
-      int sp_offset = cpu_reg_save_offsets[i];
-      oop_map->set_callee_saved(VMRegImpl::stack2reg(sp_offset),
-                                r->as_VMReg());
-    }
+  for (int i = 0; i < FrameMap::nof_caller_save_cpu_regs(); i++) {
+    LIR_Opr opr = FrameMap::caller_save_cpu_reg_at(i);
+    Register r = opr->as_register();
+    int reg_num = r->encoding();
+    int sp_offset = cpu_reg_save_offsets[reg_num];
+    oop_map->set_callee_saved(VMRegImpl::stack2reg(cpu_reg_save_offsets[reg_num]), r->as_VMReg());
   }
 
+  Register r = rthread;
+  int reg_num = r->encoding();
+  oop_map->set_callee_saved(VMRegImpl::stack2reg(cpu_reg_save_offsets[reg_num]), r->as_VMReg());
+
   if (save_fpu_registers) {
     for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
       FloatRegister r = as_FloatRegister(i);
diff --git a/src/hotspot/share/c1/c1_Compiler.cpp b/src/hotspot/share/c1/c1_Compiler.cpp
index 7d2e6ee75d9..a26320589c4 100644
--- a/src/hotspot/share/c1/c1_Compiler.cpp
+++ b/src/hotspot/share/c1/c1_Compiler.cpp
@@ -49,8 +49,8 @@ Compiler::Compiler() : AbstractCompiler(compiler_c1) {
 
 void Compiler::init_c1_runtime() {
   BufferBlob* buffer_blob = CompilerThread::current()->get_buffer_blob();
-  Runtime1::initialize(buffer_blob);
   FrameMap::initialize();
+  Runtime1::initialize(buffer_blob);
   // initialize data structures
   ValueType::initialize();
   GraphBuilder::initialize();
diff --git a/src/hotspot/share/c1/c1_FrameMap.hpp b/src/hotspot/share/c1/c1_FrameMap.hpp
index 1fd7dd3edff..dab3aa6e734 100644
--- a/src/hotspot/share/c1/c1_FrameMap.hpp
+++ b/src/hotspot/share/c1/c1_FrameMap.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2025, 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
@@ -32,6 +32,7 @@
 #include "runtime/frame.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/macros.hpp"
+#include "oops/compressedOops.hpp"
 
 class ciMethod;
 class CallingConvention;