From dfb706a51b7cf593bab660588367280328813127 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Tue, 29 Mar 2022 22:08:20 +0000
Subject: [PATCH 01/19] 8280481: Duplicated static stubs in NMethod Stub Code
 section

---
 src/hotspot/cpu/aarch64/aarch64.ad       |  8 ++---
 src/hotspot/share/asm/codeBuffer.cpp     | 41 ++++++++++++++++++++++++
 src/hotspot/share/asm/codeBuffer.hpp     | 33 +++++++++++++++++++
 src/hotspot/share/c1/c1_LIRAssembler.cpp |  7 ++--
 src/hotspot/share/ci/ciEnv.cpp           |  4 +++
 5 files changed, 85 insertions(+), 8 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/aarch64.ad b/src/hotspot/cpu/aarch64/aarch64.ad
index fe62e2fdf5201..19f3a990a6745 100644
--- a/src/hotspot/cpu/aarch64/aarch64.ad
+++ b/src/hotspot/cpu/aarch64/aarch64.ad
@@ -3810,12 +3810,8 @@ encode %{
         ciEnv::current()->record_failure("CodeCache is full");
         return;
       }
-      // Emit stub for static call
-      address stub = CompiledStaticCall::emit_to_interp_stub(cbuf);
-      if (stub == NULL) {
-        ciEnv::current()->record_failure("CodeCache is full");
-        return;
-      }
+      assert(_method->is_loaded(), "must be loaded");
+      cbuf.shared_stub_to_interp_for(_method->get_Method(), cbuf.insts_mark());
     }
 
     _masm.clear_inst_mark();
diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index ddd946d75420e..1a6243e289240 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -24,6 +24,9 @@
 
 #include "precompiled.hpp"
 #include "asm/codeBuffer.hpp"
+#include "asm/macroAssembler.hpp"
+#include "ci/ciEnv.hpp"
+#include "code/compiledIC.hpp"
 #include "code/oopRecorder.inline.hpp"
 #include "compiler/disassembler.hpp"
 #include "logging/log.hpp"
@@ -441,6 +444,7 @@ void CodeBuffer::compute_final_layout(CodeBuffer* dest) const {
   address buf = dest->_total_start;
   csize_t buf_offset = 0;
   assert(dest->_total_size >= total_content_size(), "must be big enough");
+  assert(!_finalize_stubs, "non-finalized stubs");
 
   {
     // not sure why this is here, but why not...
@@ -979,6 +983,43 @@ void CodeBuffer::log_section_sizes(const char* name) {
   }
 }
 
+static bool emit_shared_stubs_to_interp(const SharedStubToInterpRequests& requests, MacroAssembler* masm) {
+  LinkedListIterator<SharedStubToInterpRequest> it(requests.head());
+  SharedStubToInterpRequest* request = it.next();
+  while (request != NULL) {
+    address stub = masm->start_a_stub(CompiledStaticCall::to_interp_stub_size());
+    if (stub == NULL) {
+      ciEnv::current()->record_failure("CodeCache is full");
+      return false;
+    }
+    Method* method = request->shared_method();
+    do {
+      masm->relocate(static_stub_Relocation::spec(request->caller_pc()));
+      request = it.next();
+    } while (request != NULL && request->shared_method() == method);
+    masm->emit_static_call_stub();
+    masm->end_a_stub();
+  }
+  return true;
+}
+
+void CodeBuffer::finalize_stubs() {
+  MacroAssembler masm(this);
+  if (!emit_shared_stubs_to_interp(_shared_stub_to_interp_requests, &masm)) {
+    return;
+  }
+  _finalize_stubs = false;
+}
+
+void CodeBuffer::shared_stub_to_interp_for(Method* method, address caller_pc) {
+  SharedStubToInterpRequest request(method, caller_pc);
+  auto node = _shared_stub_to_interp_requests.find_node(request);
+  auto new_node = (node == NULL) ? _shared_stub_to_interp_requests.add(request)
+                                 : _shared_stub_to_interp_requests.insert_after(request, node);
+  assert(new_node != NULL, "sanity");
+  _finalize_stubs = true;
+}
+
 #ifndef PRODUCT
 void CodeBuffer::block_comment(ptrdiff_t offset, const char* comment) {
   if (_collect_comments) {
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index 207be18606752..69d643b202613 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -29,6 +29,7 @@
 #include "code/relocInfo.hpp"
 #include "utilities/align.hpp"
 #include "utilities/debug.hpp"
+#include "utilities/linkedlist.hpp"
 #include "utilities/macros.hpp"
 
 class PhaseCFG;
@@ -342,6 +343,28 @@ class Scrubber {
 };
 #endif // ASSERT
 
+// A Java method can have calls of Java methods which can be statically bound.
+// Calls of Java mehtods need stubs to the interpreter. Calls sharing the same Java method
+// can share a stub to interpreter.
+// A SharedStubToInterpRequest describes a request for a shared stub to the interpreter.
+class SharedStubToInterpRequest {
+ private:
+  Method* _shared_method;
+  address _caller_pc;
+
+ public:
+  SharedStubToInterpRequest(Method* method, address caller_pc = NULL) : _shared_method(method),
+      _caller_pc(caller_pc) {}
+
+  bool equals(const SharedStubToInterpRequest& request) const {
+    return _shared_method == request._shared_method;
+  }
+
+  Method* shared_method() { return _shared_method; }
+  address caller_pc() { return _caller_pc; }
+};
+typedef LinkedListImpl<SharedStubToInterpRequest> SharedStubToInterpRequests;
+
 // A CodeBuffer describes a memory space into which assembly
 // code is generated.  This memory space usually occupies the
 // interior of a single BufferBlob, but in some cases it may be
@@ -414,6 +437,9 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
 
   address      _last_insn;      // used to merge consecutive memory barriers, loads or stores.
 
+  SharedStubToInterpRequests _shared_stub_to_interp_requests; // used to collect requests for shared iterpreter stubs
+  bool         _finalize_stubs; // Indicate if we need to finalize stubs to make CodeBuffer final.
+
 #ifndef PRODUCT
   AsmRemarks   _asm_remarks;
   DbgStrings   _dbg_strings;
@@ -431,6 +457,7 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
     _oop_recorder    = NULL;
     _overflow_arena  = NULL;
     _last_insn       = NULL;
+    _finalize_stubs  = false;
 
 #ifndef PRODUCT
     _decode_begin    = NULL;
@@ -682,6 +709,12 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
   // Log a little info about section usage in the CodeBuffer
   void log_section_sizes(const char* name);
 
+  // Make a set of stubs final. It can create/optimize stubs.
+  void finalize_stubs();
+
+  // Request for a shared stub to the interpreter
+  void shared_stub_to_interp_for(Method* call, address caller_pc);
+
 #ifndef PRODUCT
  public:
   // Printing / Decoding
diff --git a/src/hotspot/share/c1/c1_LIRAssembler.cpp b/src/hotspot/share/c1/c1_LIRAssembler.cpp
index 0ce2485e63216..45f7955b8502f 100644
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp
@@ -456,8 +456,11 @@ void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {
   // must align calls sites, otherwise they can't be updated atomically
   align_call(op->code());
 
-  // emit the static call stub stuff out of line
-  emit_static_call_stub();
+  if (op->code() == lir_static_call && op->method()->is_loaded()) {
+    _masm->code()->shared_stub_to_interp_for(op->method()->get_Method(), pc());
+  } else {
+    emit_static_call_stub();
+  }
   CHECK_BAILOUT();
 
   switch (op->code()) {
diff --git a/src/hotspot/share/ci/ciEnv.cpp b/src/hotspot/share/ci/ciEnv.cpp
index 84eb3948f6029..a69e4cb6dce3a 100644
--- a/src/hotspot/share/ci/ciEnv.cpp
+++ b/src/hotspot/share/ci/ciEnv.cpp
@@ -1117,6 +1117,10 @@ void ciEnv::register_method(ciMethod* target,
     }
 #endif
 
+    if (!failing()) {
+      code_buffer->finalize_stubs();
+    }
+
     if (failing()) {
       // While not a true deoptimization, it is a preemptive decompile.
       MethodData* mdo = method()->method_data();

From 2e59d308ecceef9856d4cf9a701c8d87ba956712 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Wed, 30 Mar 2022 16:57:19 +0000
Subject: [PATCH 02/19] Put code into AArch64 platform part

---
 .../cpu/aarch64/codeBuffer_aarch64.cpp        | 49 +++++++++++++++++++
 .../cpu/aarch64/codeBuffer_aarch64.hpp        |  5 ++
 src/hotspot/cpu/arm/codeBuffer_arm.hpp        |  3 ++
 src/hotspot/cpu/ppc/codeBuffer_ppc.hpp        |  3 ++
 src/hotspot/cpu/riscv/codeBuffer_riscv.hpp    |  3 ++
 src/hotspot/cpu/s390/codeBuffer_s390.hpp      |  3 ++
 src/hotspot/cpu/x86/codeBuffer_x86.hpp        |  3 ++
 src/hotspot/cpu/zero/codeBuffer_zero.hpp      |  5 ++
 src/hotspot/share/asm/codeBuffer.cpp          | 26 +---------
 src/hotspot/share/c1/c1_LIRAssembler.cpp      |  3 +-
 10 files changed, 77 insertions(+), 26 deletions(-)
 create mode 100644 src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp

diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
new file mode 100644
index 0000000000000..ee7804b370fe4
--- /dev/null
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
@@ -0,0 +1,49 @@
+/*
+ * Copyright Amazon.com Inc. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "asm/codeBuffer.hpp"
+#include "asm/macroAssembler.hpp"
+#include "ci/ciEnv.hpp"
+#include "code/compiledIC.hpp"
+
+bool CodeBuffer::emit_shared_stubs_to_interp() {
+  MacroAssembler masm(this);
+  LinkedListIterator<SharedStubToInterpRequest> it(_shared_stub_to_interp_requests.head());
+  SharedStubToInterpRequest* request = it.next();
+  while (request != NULL) {
+    address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
+    if (stub == NULL) {
+      ciEnv::current()->record_failure("CodeCache is full");
+      return false;
+    }
+    Method* method = request->shared_method();
+    do {
+      masm.relocate(static_stub_Relocation::spec(request->caller_pc()));
+      request = it.next();
+    } while (request != NULL && request->shared_method() == method);
+    masm.emit_static_call_stub();
+    masm.end_a_stub();
+  }
+  return true;
+}
\ No newline at end of file
diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
index 647327f6f0890..1b5326acf628c 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
@@ -28,8 +28,13 @@
 
 private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp();
+  bool pd_finalize_stubs() {
+    return emit_shared_stubs_to_interp();
+  }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static bool supports_shared_stubs() { return true; }
 
 #endif // CPU_AARCH64_CODEBUFFER_AARCH64_HPP
diff --git a/src/hotspot/cpu/arm/codeBuffer_arm.hpp b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
index c306e6a6a0743..e992bfed1204c 100644
--- a/src/hotspot/cpu/arm/codeBuffer_arm.hpp
+++ b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
@@ -27,8 +27,11 @@
 
 private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
+  bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_ARM_CODEBUFFER_ARM_HPP
diff --git a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
index 2fb9e5657a821..56061c9a8a2a5 100644
--- a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
+++ b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
@@ -28,8 +28,11 @@
 
 private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
+  bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_PPC_CODEBUFFER_PPC_HPP
diff --git a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
index 14a68b45026da..001f606c11f55 100644
--- a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
+++ b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
@@ -29,8 +29,11 @@
 
 private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
+  bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_RISCV_CODEBUFFER_RISCV_HPP
diff --git a/src/hotspot/cpu/s390/codeBuffer_s390.hpp b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
index b1499b037a39e..4b1e8ab14cfee 100644
--- a/src/hotspot/cpu/s390/codeBuffer_s390.hpp
+++ b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
@@ -28,9 +28,12 @@
 
  private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
+  bool pd_finalize_stubs() { return true; }
 
  public:
   void flush_bundle(bool start_new_bundle) {}
+  static bool supports_shared_stubs() { return false; }
 
   void getCpuData(const CodeBuffer * const cb) {}
 
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.hpp b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
index ae03833595c96..3ee16d151e62e 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.hpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
@@ -27,8 +27,11 @@
 
 private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
+  bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_X86_CODEBUFFER_X86_HPP
diff --git a/src/hotspot/cpu/zero/codeBuffer_zero.hpp b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
index f35294be0c12e..9cac37129d8dc 100644
--- a/src/hotspot/cpu/zero/codeBuffer_zero.hpp
+++ b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
@@ -28,5 +28,10 @@
 
  private:
   void pd_initialize() {}
+  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
+  bool pd_finalize_stubs() { return true; }
+
+ public:
+  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_ZERO_CODEBUFFER_ZERO_HPP
diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index 1a6243e289240..71582eaf92352 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -24,9 +24,6 @@
 
 #include "precompiled.hpp"
 #include "asm/codeBuffer.hpp"
-#include "asm/macroAssembler.hpp"
-#include "ci/ciEnv.hpp"
-#include "code/compiledIC.hpp"
 #include "code/oopRecorder.inline.hpp"
 #include "compiler/disassembler.hpp"
 #include "logging/log.hpp"
@@ -983,29 +980,8 @@ void CodeBuffer::log_section_sizes(const char* name) {
   }
 }
 
-static bool emit_shared_stubs_to_interp(const SharedStubToInterpRequests& requests, MacroAssembler* masm) {
-  LinkedListIterator<SharedStubToInterpRequest> it(requests.head());
-  SharedStubToInterpRequest* request = it.next();
-  while (request != NULL) {
-    address stub = masm->start_a_stub(CompiledStaticCall::to_interp_stub_size());
-    if (stub == NULL) {
-      ciEnv::current()->record_failure("CodeCache is full");
-      return false;
-    }
-    Method* method = request->shared_method();
-    do {
-      masm->relocate(static_stub_Relocation::spec(request->caller_pc()));
-      request = it.next();
-    } while (request != NULL && request->shared_method() == method);
-    masm->emit_static_call_stub();
-    masm->end_a_stub();
-  }
-  return true;
-}
-
 void CodeBuffer::finalize_stubs() {
-  MacroAssembler masm(this);
-  if (!emit_shared_stubs_to_interp(_shared_stub_to_interp_requests, &masm)) {
+  if (!pd_finalize_stubs()) {
     return;
   }
   _finalize_stubs = false;
diff --git a/src/hotspot/share/c1/c1_LIRAssembler.cpp b/src/hotspot/share/c1/c1_LIRAssembler.cpp
index 45f7955b8502f..76cccc11e0340 100644
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp
@@ -456,7 +456,8 @@ void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {
   // must align calls sites, otherwise they can't be updated atomically
   align_call(op->code());
 
-  if (op->code() == lir_static_call && op->method()->is_loaded()) {
+  if (CodeBuffer::supports_shared_stubs() && op->code() == lir_static_call
+      && op->method()->is_loaded()) {
     _masm->code()->shared_stub_to_interp_for(op->method()->get_Method(), pc());
   } else {
     emit_static_call_stub();

From 00a31b13bcefe8931063f224cbf8a5a5d02c2a2f Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Wed, 30 Mar 2022 17:22:05 +0000
Subject: [PATCH 03/19] Fix missing precompiled.hpp error

---
 src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
index ee7804b370fe4..0914db8dfa871 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
@@ -22,6 +22,7 @@
  *
  */
 
+#include "precompiled.hpp"
 #include "asm/codeBuffer.hpp"
 #include "asm/macroAssembler.hpp"
 #include "ci/ciEnv.hpp"
@@ -46,4 +47,4 @@ bool CodeBuffer::emit_shared_stubs_to_interp() {
     masm.end_a_stub();
   }
   return true;
-}
\ No newline at end of file
+}

From 902e78b561a6e10db8162bf80c8e25738b8bcd2c Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 8 Apr 2022 09:33:40 +0000
Subject: [PATCH 04/19] Add a test and implementation fixes

---
 src/hotspot/cpu/aarch64/aarch64.ad            |  16 +-
 src/hotspot/share/c1/c1_LIRAssembler.cpp      |  10 +-
 .../sharedstubs/SharedStubToInterpTest.java   | 182 ++++++++++++++++++
 3 files changed, 204 insertions(+), 4 deletions(-)
 create mode 100644 test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java

diff --git a/src/hotspot/cpu/aarch64/aarch64.ad b/src/hotspot/cpu/aarch64/aarch64.ad
index 19f3a990a6745..34b05e92edbb2 100644
--- a/src/hotspot/cpu/aarch64/aarch64.ad
+++ b/src/hotspot/cpu/aarch64/aarch64.ad
@@ -3810,8 +3810,20 @@ encode %{
         ciEnv::current()->record_failure("CodeCache is full");
         return;
       }
-      assert(_method->is_loaded(), "must be loaded");
-      cbuf.shared_stub_to_interp_for(_method->get_Method(), cbuf.insts_mark());
+      if (CodeBuffer::supports_shared_stubs() &&
+          _method->is_loaded() &&
+          (!_optimized_virtual || _method->is_final_method())) {
+        // Postpone creating a stub to the interpreter because
+        // it might be shared among calls of the same Java method.
+        cbuf.shared_stub_to_interp_for(_method->get_Method(), cbuf.insts_mark());
+      } else {
+        // Emit stub for static call
+        address stub = CompiledStaticCall::emit_to_interp_stub(cbuf);
+        if (stub == NULL) {
+          ciEnv::current()->record_failure("CodeCache is full");
+          return;
+        }
+      }
     }
 
     _masm.clear_inst_mark();
diff --git a/src/hotspot/share/c1/c1_LIRAssembler.cpp b/src/hotspot/share/c1/c1_LIRAssembler.cpp
index 76cccc11e0340..893e54e3b13cf 100644
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp
@@ -449,6 +449,11 @@ void LIR_Assembler::emit_rtcall(LIR_OpRTCall* op) {
   rt_call(op->result_opr(), op->addr(), op->arguments(), op->tmp(), op->info());
 }
 
+static bool can_use_shared_stub_for(LIR_OpJavaCall* op) {
+  return CodeBuffer::supports_shared_stubs() &&
+         op->method()->is_loaded() &&
+         (op->code() == lir_static_call || op->method()->is_final_method());
+}
 
 void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {
   verify_oop_map(op->info());
@@ -456,8 +461,9 @@ void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {
   // must align calls sites, otherwise they can't be updated atomically
   align_call(op->code());
 
-  if (CodeBuffer::supports_shared_stubs() && op->code() == lir_static_call
-      && op->method()->is_loaded()) {
+  if (can_use_shared_stub_for(op)) {
+    // Postpone creating a stub to the interpreter.
+    // It might be shared among calls of the same Java method.
     _masm->code()->shared_stub_to_interp_for(op->method()->get_Method(), pc());
   } else {
     emit_static_call_stub();
diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
new file mode 100644
index 0000000000000..11952a16fc36d
--- /dev/null
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -0,0 +1,182 @@
+/*
+ * Copyright Amazon.com Inc. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/**
+ * @test SharedStubToInterpTest
+ * @summary Checks that stubs to the interpreter can be shared for static or final method.
+ * @bug 8280481
+ * @library /test/lib
+ *
+ * @requires os.arch=="aarch64"
+ *
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 StaticMethodTest
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 StaticMethodTest
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 FinalClassTest
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 FinalClassTest
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 FinalMethodTest
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 FinalMethodTest
+ */
+
+package compiler.sharedstubs;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.ListIterator;
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+
+public class SharedStubToInterpTest {
+    public static void main(String[] args) throws Exception {
+        String compiler = args[0];
+        String testClassName = SharedStubToInterpTest.class.getName() + "$" + args[1];
+        ArrayList<String> command = new ArrayList<String>();
+        command.add("-XX:+IgnoreUnrecognizedVMOptions");
+        command.add("-XX:+UnlockDiagnosticVMOptions");
+        if (compiler.equals("c2")) {
+            command.add("-XX:-TieredCompilation");
+        } else if (compiler.equals("c1")) {
+            command.add("-XX:TieredStopAtLevel=1");
+        } else {
+            throw new RuntimeException("Unknown compiler: " + compiler);
+        }
+        command.add("-Xbatch");
+        command.add("-XX:CompileCommand=compileonly," + testClassName + "::" + "test");
+        command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "test");
+        command.add("-XX:CompileCommand=print," + testClassName + "::" + "test");
+        command.add("-XX:CompileCommand=exclude," + testClassName + "::" + "log");
+        command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "log");
+        command.add(testClassName);
+        command.add("a");
+        command.add("b");
+        command.add("c");
+
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(command);
+
+        OutputAnalyzer analyzer = new OutputAnalyzer(pb.start());
+
+        analyzer.shouldHaveExitValue(0);
+
+        System.out.println(analyzer.getOutput());
+
+        checkOutput(analyzer);
+    }
+
+    private static String skipTo(Iterator<String> iter, String substring) {
+        while (iter.hasNext()) {
+            String nextLine = iter.next();
+            if (nextLine.contains(substring)) {
+                return nextLine;
+            }
+        }
+        return null;
+    }
+
+    private static void checkOutput(OutputAnalyzer output) {
+        Iterator<String> iter = output.asLines().listIterator();
+
+        String match = skipTo(iter, "Compiled method");
+        while (match != null && !match.contains("Test::test")) {
+            match = skipTo(iter, "Compiled method");
+        }
+        if (match == null) {
+            throw new RuntimeException("Missing compiler output for the method 'test'");
+        }
+
+        // Shared static stubs are put after Deopt Handler Code.
+        match = skipTo(iter, "[Deopt Handler Code]");
+        if (match == null) {
+            throw new RuntimeException("The start of Deopt Handler Code not found");
+        }
+        int foundStaticStubs = 0;
+        while (iter.hasNext()) {
+            if (iter.next().contains("{static_stub}")) {
+                foundStaticStubs += 1;
+            }
+        }
+
+        final int expectedStaticStubs = 1;
+        if (foundStaticStubs != expectedStaticStubs) {
+            throw new RuntimeException("Found static stubs: " + foundStaticStubs + "; Expected static stubs: " + expectedStaticStubs);
+        }
+    }
+
+    public static class StaticMethodTest {
+        static void log(int i) {
+        }
+
+        static void test(int i, String[] args) {
+            if (i % args.length == 0) {
+                log(i);
+            } else {
+                log(i);
+            }
+        }
+
+        public static void main(String[] args) {
+            for (int i = 1; i < 50_000; ++i) {
+                test(i, args);
+            }
+        }
+    }
+
+    public static final class FinalClassTest {
+        void log(int i) {
+        }
+
+        void test(int i, String[] args) {
+            if (i % args.length == 0) {
+                log(i);
+            } else {
+                log(i);
+            }
+        }
+
+        public static void main(String[] args) {
+            FinalClassTest tFC = new FinalClassTest();
+            for (int i = 1; i < 50_000; ++i) {
+                tFC.test(i,args);
+            }
+        }
+    }
+
+    public static class FinalMethodTest {
+        final void log(int i) {
+        }
+
+        void test(int i, String[] args) {
+            if (i % args.length == 0) {
+                log(i);
+            } else {
+                log(i);
+            }
+        }
+
+        public static void main(String[] args) {
+            FinalMethodTest tFM = new FinalMethodTest();
+            for (int i = 1; i < 50_000; ++i) {
+                tFM.test(i,args);
+            }
+        }
+    }
+}

From 107efe0879447a6f1978c7f82f8897991af0ef50 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 8 Apr 2022 20:09:45 +0000
Subject: [PATCH 05/19] Resolve merge conflict in x86_32.ad

---
 src/hotspot/cpu/x86/codeBuffer_x86.cpp        | 50 +++++++++++++++++++
 src/hotspot/cpu/x86/codeBuffer_x86.hpp        |  8 +--
 src/hotspot/cpu/x86/compiledIC_x86.cpp        |  5 +-
 src/hotspot/cpu/x86/macroAssembler_x86.cpp    |  7 +++
 src/hotspot/cpu/x86/macroAssembler_x86.hpp    |  2 +
 src/hotspot/cpu/x86/x86_32.ad                 | 19 +++++--
 src/hotspot/cpu/x86/x86_64.ad                 | 18 +++++--
 .../sharedstubs/SharedStubToInterpTest.java   |  4 +-
 8 files changed, 94 insertions(+), 19 deletions(-)
 create mode 100644 src/hotspot/cpu/x86/codeBuffer_x86.cpp

diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.cpp b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
new file mode 100644
index 0000000000000..6f49b54bd7df2
--- /dev/null
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright Amazon.com Inc. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "asm/codeBuffer.hpp"
+#include "asm/macroAssembler.hpp"
+#include "ci/ciEnv.hpp"
+#include "code/compiledIC.hpp"
+
+bool CodeBuffer::emit_shared_stubs_to_interp() {
+  MacroAssembler masm(this);
+  LinkedListIterator<SharedStubToInterpRequest> it(_shared_stub_to_interp_requests.head());
+  SharedStubToInterpRequest* request = it.next();
+  while (request != NULL) {
+    address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
+    if (stub == NULL) {
+      ciEnv::current()->record_failure("CodeCache is full");
+      return false;
+    }
+    Method* method = request->shared_method();
+    do {
+      masm.relocate(static_stub_Relocation::spec(request->caller_pc()), Assembler::imm_operand);
+      request = it.next();
+    } while (request != NULL && request->shared_method() == method);
+    masm.emit_static_call_stub();
+    masm.end_a_stub();
+  }
+  return true;
+}
\ No newline at end of file
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.hpp b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
index 3ee16d151e62e..729325caf9a5e 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.hpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
@@ -27,11 +27,13 @@
 
 private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
-  bool pd_finalize_stubs() { return true; }
+  bool emit_shared_stubs_to_interp();
+  bool pd_finalize_stubs() {
+    return emit_shared_stubs_to_interp();
+  }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return false; }
+  static bool supports_shared_stubs() { return true; }
 
 #endif // CPU_X86_CODEBUFFER_X86_HPP
diff --git a/src/hotspot/cpu/x86/compiledIC_x86.cpp b/src/hotspot/cpu/x86/compiledIC_x86.cpp
index e898e523c0fe9..d9d97d75033e0 100644
--- a/src/hotspot/cpu/x86/compiledIC_x86.cpp
+++ b/src/hotspot/cpu/x86/compiledIC_x86.cpp
@@ -55,10 +55,7 @@ address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark)
   }
   // Static stub relocation stores the instruction address of the call.
   __ relocate(static_stub_Relocation::spec(mark), Assembler::imm_operand);
-  // Static stub relocation also tags the Method* in the code-stream.
-  __ mov_metadata(rbx, (Metadata*) NULL);  // Method is zapped till fixup time.
-  // This is recognized as unresolved by relocs/nativeinst/ic code.
-  __ jump(RuntimeAddress(__ pc()));
+  __ emit_static_call_stub();
 
   assert(__ pc() - base <= to_interp_stub_size(), "wrong stub size");
 
diff --git a/src/hotspot/cpu/x86/macroAssembler_x86.cpp b/src/hotspot/cpu/x86/macroAssembler_x86.cpp
index bca825468ff04..1417f77b73282 100644
--- a/src/hotspot/cpu/x86/macroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/macroAssembler_x86.cpp
@@ -1328,6 +1328,13 @@ void MacroAssembler::ic_call(address entry, jint method_index) {
   call(AddressLiteral(entry, rh));
 }
 
+void MacroAssembler::emit_static_call_stub() {
+  // Static stub relocation also tags the Method* in the code-stream.
+  mov_metadata(rbx, (Metadata*) NULL);  // Method is zapped till fixup time.
+  // This is recognized as unresolved by relocs/nativeinst/ic code.
+  jump(RuntimeAddress(pc()));
+}
+
 // Implementation of call_VM versions
 
 void MacroAssembler::call_VM(Register oop_result,
diff --git a/src/hotspot/cpu/x86/macroAssembler_x86.hpp b/src/hotspot/cpu/x86/macroAssembler_x86.hpp
index 54d1a0c2c6948..6dc3baebe8314 100644
--- a/src/hotspot/cpu/x86/macroAssembler_x86.hpp
+++ b/src/hotspot/cpu/x86/macroAssembler_x86.hpp
@@ -865,6 +865,8 @@ class MacroAssembler: public Assembler {
   // Emit the CompiledIC call idiom
   void ic_call(address entry, jint method_index = 0);
 
+  void emit_static_call_stub();
+
   // Jumps
 
   // NOTE: these jumps transfer to the effective address of dst NOT
diff --git a/src/hotspot/cpu/x86/x86_32.ad b/src/hotspot/cpu/x86/x86_32.ad
index dbbfb7c92603f..21c5a8b7e4020 100644
--- a/src/hotspot/cpu/x86/x86_32.ad
+++ b/src/hotspot/cpu/x86/x86_32.ad
@@ -1813,11 +1813,20 @@ encode %{
       emit_d32_reloc(cbuf, ($meth$$method - (int)(cbuf.insts_end()) - 4),
                      rspec, RELOC_DISP32);
       __ post_call_nop();
-      // Emit stubs for static call.
-      address stub = CompiledStaticCall::emit_to_interp_stub(cbuf);
-      if (stub == NULL) {
-        ciEnv::current()->record_failure("CodeCache is full");
-        return;
+      address mark = cbuf.insts_mark();
+      if (CodeBuffer::supports_shared_stubs() &&
+          _method->is_loaded() &&
+          (!_optimized_virtual || _method->is_final_method())) {
+        // Postpone creating a stub to the interpreter because
+        // it might be shared among calls of the same Java method.
+        cbuf.shared_stub_to_interp_for(_method->get_Method(), mark);
+      } else {
+        // Emit stubs for static call.
+        address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);
+        if (stub == NULL) {
+          ciEnv::current()->record_failure("CodeCache is full");
+          return;
+        }
       }
     }
   %}
diff --git a/src/hotspot/cpu/x86/x86_64.ad b/src/hotspot/cpu/x86/x86_64.ad
index 8e7c04f4d1e55..8a11685cc99e1 100644
--- a/src/hotspot/cpu/x86/x86_64.ad
+++ b/src/hotspot/cpu/x86/x86_64.ad
@@ -2168,12 +2168,20 @@ encode %{
                                                   : static_call_Relocation::spec(method_index);
       emit_d32_reloc(cbuf, (int) ($meth$$method - ((intptr_t) cbuf.insts_end()) - 4),
                      rspec, RELOC_DISP32);
-      // Emit stubs for static call.
       address mark = cbuf.insts_mark();
-      address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);
-      if (stub == NULL) {
-        ciEnv::current()->record_failure("CodeCache is full");
-        return;
+      if (CodeBuffer::supports_shared_stubs() &&
+          _method->is_loaded() &&
+          (!_optimized_virtual || _method->is_final_method())) {
+        // Postpone creating a stub to the interpreter because
+        // it might be shared among calls of the same Java method.
+        cbuf.shared_stub_to_interp_for(_method->get_Method(), mark);
+      } else {
+        // Emit stubs for static call.
+        address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);
+        if (stub == NULL) {
+          ciEnv::current()->record_failure("CodeCache is full");
+          return;
+        }
       }
     }
     _masm.clear_inst_mark();
diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
index 11952a16fc36d..9f35fb53f44f0 100644
--- a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -28,7 +28,7 @@
  * @bug 8280481
  * @library /test/lib
  *
- * @requires os.arch=="aarch64"
+ * @requires os.arch=="amd64" | os.arch=="x86_64" | os.arch=="i386" | os.arch=="x86" | os.arch=="aarch64"
  *
  * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 StaticMethodTest
  * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 StaticMethodTest
@@ -104,7 +104,7 @@ private static void checkOutput(OutputAnalyzer output) {
         }
 
         // Shared static stubs are put after Deopt Handler Code.
-        match = skipTo(iter, "[Deopt Handler Code]");
+        match = skipTo(iter, "{runtime_call DeoptimizationBlob}");
         if (match == null) {
             throw new RuntimeException("The start of Deopt Handler Code not found");
         }

From 22df6e69a73c4c3a8636cf073cddf30e28e06905 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Mon, 11 Apr 2022 14:00:10 +0000
Subject: [PATCH 06/19] Refactor code to be shared with aarch64

---
 src/hotspot/cpu/x86/codeBuffer_x86.cpp      | 27 ++-------
 src/hotspot/cpu/x86/codeBuffer_x86.hpp      |  5 +-
 src/hotspot/share/asm/codeBuffer.inline.hpp | 61 +++++++++++++++++++++
 3 files changed, 66 insertions(+), 27 deletions(-)
 create mode 100644 src/hotspot/share/asm/codeBuffer.inline.hpp

diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.cpp b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
index 6f49b54bd7df2..3c406ed1b198e 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.cpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
@@ -23,28 +23,9 @@
  */
 
 #include "precompiled.hpp"
-#include "asm/codeBuffer.hpp"
+#include "asm/codeBuffer.inline.hpp"
 #include "asm/macroAssembler.hpp"
-#include "ci/ciEnv.hpp"
-#include "code/compiledIC.hpp"
 
-bool CodeBuffer::emit_shared_stubs_to_interp() {
-  MacroAssembler masm(this);
-  LinkedListIterator<SharedStubToInterpRequest> it(_shared_stub_to_interp_requests.head());
-  SharedStubToInterpRequest* request = it.next();
-  while (request != NULL) {
-    address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
-    if (stub == NULL) {
-      ciEnv::current()->record_failure("CodeCache is full");
-      return false;
-    }
-    Method* method = request->shared_method();
-    do {
-      masm.relocate(static_stub_Relocation::spec(request->caller_pc()), Assembler::imm_operand);
-      request = it.next();
-    } while (request != NULL && request->shared_method() == method);
-    masm.emit_static_call_stub();
-    masm.end_a_stub();
-  }
-  return true;
-}
\ No newline at end of file
+bool CodeBuffer::pd_finalize_stubs() {
+  return emit_shared_stubs_to_interp<MacroAssembler, Assembler::imm_operand>(this, _shared_stub_to_interp_requests);
+}
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.hpp b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
index 729325caf9a5e..2069f20ac2f3e 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.hpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
@@ -27,10 +27,7 @@
 
 private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp();
-  bool pd_finalize_stubs() {
-    return emit_shared_stubs_to_interp();
-  }
+  bool pd_finalize_stubs();
 
 public:
   void flush_bundle(bool start_new_bundle) {}
diff --git a/src/hotspot/share/asm/codeBuffer.inline.hpp b/src/hotspot/share/asm/codeBuffer.inline.hpp
new file mode 100644
index 0000000000000..4361717794126
--- /dev/null
+++ b/src/hotspot/share/asm/codeBuffer.inline.hpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright Amazon.com Inc. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_ASM_CODEBUFFER_INLINE_HPP
+#define SHARE_ASM_CODEBUFFER_INLINE_HPP
+
+#include "asm/codeBuffer.hpp"
+#include "ci/ciEnv.hpp"
+#include "code/compiledIC.hpp"
+
+template <typename MacroAssembler, int relocate_format = 0>
+bool emit_shared_stubs_to_interp(CodeBuffer* cb, const SharedStubToInterpRequests& shared_stub_to_interp_requests) {
+  MacroAssembler masm(cb);
+  LinkedListIterator<SharedStubToInterpRequest> it(shared_stub_to_interp_requests.head());
+  SharedStubToInterpRequest* request = it.next();
+  int relocations_created = 0;
+  while (request != NULL) {
+    address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
+    if (stub == NULL) {
+      ciEnv::current()->record_failure("CodeCache is full");
+      return false;
+    }
+    Method* method = request->shared_method();
+    do {
+      masm.relocate(static_stub_Relocation::spec(request->caller_pc()), relocate_format);
+      request = it.next();
+      ++relocations_created;
+    } while (request != NULL && request->shared_method() == method);
+    masm.emit_static_call_stub();
+    masm.end_a_stub();
+  }
+
+  if (relocations_created > 1 && UseNewCode) {
+    tty->print_cr("Requests %d", (int)shared_stub_to_interp_requests.size());
+    tty->print_cr("Saved %d", (relocations_created-1)*CompiledStaticCall::to_interp_stub_size());
+  }
+  return true;
+}
+
+#endif // SHARE_ASM_CODEBUFFER_INLINE_HPP

From 1c8b80308981cba66841be384f901c9be1adf9e5 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Mon, 11 Apr 2022 16:52:19 +0000
Subject: [PATCH 07/19] Add UseSharedStubs option

---
 src/hotspot/cpu/aarch64/aarch64.ad            |  3 +--
 .../cpu/aarch64/codeBuffer_aarch64.cpp        | 25 +++----------------
 .../cpu/aarch64/codeBuffer_aarch64.hpp        |  6 +----
 src/hotspot/cpu/arm/codeBuffer_arm.hpp        |  2 --
 src/hotspot/cpu/ppc/codeBuffer_ppc.hpp        |  2 --
 src/hotspot/cpu/riscv/codeBuffer_riscv.hpp    |  2 --
 src/hotspot/cpu/s390/codeBuffer_s390.hpp      |  2 --
 src/hotspot/cpu/x86/codeBuffer_x86.hpp        |  1 -
 src/hotspot/cpu/x86/x86_32.ad                 |  3 +--
 src/hotspot/cpu/x86/x86_64.ad                 |  3 +--
 src/hotspot/cpu/zero/codeBuffer_zero.hpp      |  4 ---
 src/hotspot/share/c1/c1_LIRAssembler.cpp      |  2 +-
 src/hotspot/share/runtime/globals.hpp         |  3 +++
 .../sharedstubs/SharedStubToInterpTest.java   |  1 +
 14 files changed, 12 insertions(+), 47 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/aarch64.ad b/src/hotspot/cpu/aarch64/aarch64.ad
index 34b05e92edbb2..d3aa95a0f82a2 100644
--- a/src/hotspot/cpu/aarch64/aarch64.ad
+++ b/src/hotspot/cpu/aarch64/aarch64.ad
@@ -3810,8 +3810,7 @@ encode %{
         ciEnv::current()->record_failure("CodeCache is full");
         return;
       }
-      if (CodeBuffer::supports_shared_stubs() &&
-          _method->is_loaded() &&
+      if (UseSharedStubs && _method->is_loaded() &&
           (!_optimized_virtual || _method->is_final_method())) {
         // Postpone creating a stub to the interpreter because
         // it might be shared among calls of the same Java method.
diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
index 0914db8dfa871..4257782fdc2cb 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
@@ -23,28 +23,9 @@
  */
 
 #include "precompiled.hpp"
-#include "asm/codeBuffer.hpp"
+#include "asm/codeBuffer.inline.hpp"
 #include "asm/macroAssembler.hpp"
-#include "ci/ciEnv.hpp"
-#include "code/compiledIC.hpp"
 
-bool CodeBuffer::emit_shared_stubs_to_interp() {
-  MacroAssembler masm(this);
-  LinkedListIterator<SharedStubToInterpRequest> it(_shared_stub_to_interp_requests.head());
-  SharedStubToInterpRequest* request = it.next();
-  while (request != NULL) {
-    address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
-    if (stub == NULL) {
-      ciEnv::current()->record_failure("CodeCache is full");
-      return false;
-    }
-    Method* method = request->shared_method();
-    do {
-      masm.relocate(static_stub_Relocation::spec(request->caller_pc()));
-      request = it.next();
-    } while (request != NULL && request->shared_method() == method);
-    masm.emit_static_call_stub();
-    masm.end_a_stub();
-  }
-  return true;
+bool CodeBuffer::pd_finalize_stubs() {
+  return emit_shared_stubs_to_interp<MacroAssembler>(this, _shared_stub_to_interp_requests);
 }
diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
index 1b5326acf628c..104eeccc7a1eb 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
@@ -28,13 +28,9 @@
 
 private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp();
-  bool pd_finalize_stubs() {
-    return emit_shared_stubs_to_interp();
-  }
+  bool pd_finalize_stubs();
 
 public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return true; }
 
 #endif // CPU_AARCH64_CODEBUFFER_AARCH64_HPP
diff --git a/src/hotspot/cpu/arm/codeBuffer_arm.hpp b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
index e992bfed1204c..375428ca86eeb 100644
--- a/src/hotspot/cpu/arm/codeBuffer_arm.hpp
+++ b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
@@ -27,11 +27,9 @@
 
 private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
   bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_ARM_CODEBUFFER_ARM_HPP
diff --git a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
index 56061c9a8a2a5..a71b573381745 100644
--- a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
+++ b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
@@ -28,11 +28,9 @@
 
 private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
   bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_PPC_CODEBUFFER_PPC_HPP
diff --git a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
index 001f606c11f55..7a69cf8c261b4 100644
--- a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
+++ b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
@@ -29,11 +29,9 @@
 
 private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
   bool pd_finalize_stubs() { return true; }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return false; }
 
 #endif // CPU_RISCV_CODEBUFFER_RISCV_HPP
diff --git a/src/hotspot/cpu/s390/codeBuffer_s390.hpp b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
index 4b1e8ab14cfee..5dcd6c249db88 100644
--- a/src/hotspot/cpu/s390/codeBuffer_s390.hpp
+++ b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
@@ -28,12 +28,10 @@
 
  private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
   bool pd_finalize_stubs() { return true; }
 
  public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return false; }
 
   void getCpuData(const CodeBuffer * const cb) {}
 
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.hpp b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
index 2069f20ac2f3e..7a8fae033fd40 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.hpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
@@ -31,6 +31,5 @@
 
 public:
   void flush_bundle(bool start_new_bundle) {}
-  static bool supports_shared_stubs() { return true; }
 
 #endif // CPU_X86_CODEBUFFER_X86_HPP
diff --git a/src/hotspot/cpu/x86/x86_32.ad b/src/hotspot/cpu/x86/x86_32.ad
index 21c5a8b7e4020..bffabf0228fd7 100644
--- a/src/hotspot/cpu/x86/x86_32.ad
+++ b/src/hotspot/cpu/x86/x86_32.ad
@@ -1814,8 +1814,7 @@ encode %{
                      rspec, RELOC_DISP32);
       __ post_call_nop();
       address mark = cbuf.insts_mark();
-      if (CodeBuffer::supports_shared_stubs() &&
-          _method->is_loaded() &&
+      if (UseSharedStubs && _method->is_loaded() &&
           (!_optimized_virtual || _method->is_final_method())) {
         // Postpone creating a stub to the interpreter because
         // it might be shared among calls of the same Java method.
diff --git a/src/hotspot/cpu/x86/x86_64.ad b/src/hotspot/cpu/x86/x86_64.ad
index 8a11685cc99e1..c143c2a33add5 100644
--- a/src/hotspot/cpu/x86/x86_64.ad
+++ b/src/hotspot/cpu/x86/x86_64.ad
@@ -2169,8 +2169,7 @@ encode %{
       emit_d32_reloc(cbuf, (int) ($meth$$method - ((intptr_t) cbuf.insts_end()) - 4),
                      rspec, RELOC_DISP32);
       address mark = cbuf.insts_mark();
-      if (CodeBuffer::supports_shared_stubs() &&
-          _method->is_loaded() &&
+      if (UseSharedStubs && _method->is_loaded() &&
           (!_optimized_virtual || _method->is_final_method())) {
         // Postpone creating a stub to the interpreter because
         // it might be shared among calls of the same Java method.
diff --git a/src/hotspot/cpu/zero/codeBuffer_zero.hpp b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
index 9cac37129d8dc..82831e51baaa1 100644
--- a/src/hotspot/cpu/zero/codeBuffer_zero.hpp
+++ b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
@@ -28,10 +28,6 @@
 
  private:
   void pd_initialize() {}
-  bool emit_shared_stubs_to_interp() { Unimplemented(); return true; }
   bool pd_finalize_stubs() { return true; }
 
- public:
-  static bool supports_shared_stubs() { return false; }
-
 #endif // CPU_ZERO_CODEBUFFER_ZERO_HPP
diff --git a/src/hotspot/share/c1/c1_LIRAssembler.cpp b/src/hotspot/share/c1/c1_LIRAssembler.cpp
index 893e54e3b13cf..e3ad26194f274 100644
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp
@@ -450,7 +450,7 @@ void LIR_Assembler::emit_rtcall(LIR_OpRTCall* op) {
 }
 
 static bool can_use_shared_stub_for(LIR_OpJavaCall* op) {
-  return CodeBuffer::supports_shared_stubs() &&
+  return UseSharedStubs &&
          op->method()->is_loaded() &&
          (op->code() == lir_static_call || op->method()->is_final_method());
 }
diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
index 69c16b244dc92..fe4645be713eb 100644
--- a/src/hotspot/share/runtime/globals.hpp
+++ b/src/hotspot/share/runtime/globals.hpp
@@ -2054,6 +2054,9 @@ const intx ObjectAlignmentInBytes = 8;
                                                                             \
   develop(bool, TraceOptimizedUpcallStubs, false,                              \
                 "Trace optimized upcall stub generation")                      \
+  product(bool, UseSharedStubs, false, DIAGNOSTIC,                          \
+                "Allow sharing stubs whether it is possible")               \
+                                                                            \
 
 // end of RUNTIME_FLAGS
 
diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
index 9f35fb53f44f0..d5232df30aea8 100644
--- a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -61,6 +61,7 @@ public static void main(String[] args) throws Exception {
             throw new RuntimeException("Unknown compiler: " + compiler);
         }
         command.add("-Xbatch");
+        command.add("-XX:+UseSharedStubs");
         command.add("-XX:CompileCommand=compileonly," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=print," + testClassName + "::" + "test");

From 475968b931957002fa0c9ca1706986049e86805d Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Mon, 11 Apr 2022 17:57:30 +0000
Subject: [PATCH 08/19] Use array for SharedStubToInterpRequests to be able to
 sort

---
 .../cpu/aarch64/codeBuffer_aarch64.cpp        |  2 +-
 src/hotspot/cpu/x86/codeBuffer_x86.cpp        |  2 +-
 src/hotspot/share/asm/codeBuffer.cpp          |  5 +---
 src/hotspot/share/asm/codeBuffer.hpp          | 14 ++++-----
 src/hotspot/share/asm/codeBuffer.inline.hpp   | 30 +++++++++++++------
 5 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
index 4257782fdc2cb..78b69aecba06a 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
@@ -27,5 +27,5 @@
 #include "asm/macroAssembler.hpp"
 
 bool CodeBuffer::pd_finalize_stubs() {
-  return emit_shared_stubs_to_interp<MacroAssembler>(this, _shared_stub_to_interp_requests);
+  return emit_shared_stubs_to_interp<MacroAssembler>(this, &_shared_stub_to_interp_requests);
 }
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.cpp b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
index 3c406ed1b198e..1e6ef09003277 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.cpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
@@ -27,5 +27,5 @@
 #include "asm/macroAssembler.hpp"
 
 bool CodeBuffer::pd_finalize_stubs() {
-  return emit_shared_stubs_to_interp<MacroAssembler, Assembler::imm_operand>(this, _shared_stub_to_interp_requests);
+  return emit_shared_stubs_to_interp<MacroAssembler, Assembler::imm_operand>(this, &_shared_stub_to_interp_requests);
 }
diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index 71582eaf92352..d5ef305fffd12 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -989,10 +989,7 @@ void CodeBuffer::finalize_stubs() {
 
 void CodeBuffer::shared_stub_to_interp_for(Method* method, address caller_pc) {
   SharedStubToInterpRequest request(method, caller_pc);
-  auto node = _shared_stub_to_interp_requests.find_node(request);
-  auto new_node = (node == NULL) ? _shared_stub_to_interp_requests.add(request)
-                                 : _shared_stub_to_interp_requests.insert_after(request, node);
-  assert(new_node != NULL, "sanity");
+  _shared_stub_to_interp_requests.push(request);
   _finalize_stubs = true;
 }
 
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index 69d643b202613..9160d11f7205d 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -29,7 +29,7 @@
 #include "code/relocInfo.hpp"
 #include "utilities/align.hpp"
 #include "utilities/debug.hpp"
-#include "utilities/linkedlist.hpp"
+#include "utilities/growableArray.hpp"
 #include "utilities/macros.hpp"
 
 class PhaseCFG;
@@ -353,17 +353,13 @@ class SharedStubToInterpRequest {
   address _caller_pc;
 
  public:
-  SharedStubToInterpRequest(Method* method, address caller_pc = NULL) : _shared_method(method),
+  SharedStubToInterpRequest(Method* method = NULL, address caller_pc = NULL) : _shared_method(method),
       _caller_pc(caller_pc) {}
 
-  bool equals(const SharedStubToInterpRequest& request) const {
-    return _shared_method == request._shared_method;
-  }
-
-  Method* shared_method() { return _shared_method; }
-  address caller_pc() { return _caller_pc; }
+  Method* shared_method() const { return _shared_method; }
+  address caller_pc() const { return _caller_pc; }
 };
-typedef LinkedListImpl<SharedStubToInterpRequest> SharedStubToInterpRequests;
+typedef GrowableArray<SharedStubToInterpRequest> SharedStubToInterpRequests;
 
 // A CodeBuffer describes a memory space into which assembly
 // code is generated.  This memory space usually occupies the
diff --git a/src/hotspot/share/asm/codeBuffer.inline.hpp b/src/hotspot/share/asm/codeBuffer.inline.hpp
index 4361717794126..d0cbc4f971a9d 100644
--- a/src/hotspot/share/asm/codeBuffer.inline.hpp
+++ b/src/hotspot/share/asm/codeBuffer.inline.hpp
@@ -30,29 +30,41 @@
 #include "code/compiledIC.hpp"
 
 template <typename MacroAssembler, int relocate_format = 0>
-bool emit_shared_stubs_to_interp(CodeBuffer* cb, const SharedStubToInterpRequests& shared_stub_to_interp_requests) {
+bool emit_shared_stubs_to_interp(CodeBuffer* cb, SharedStubToInterpRequests* shared_stub_to_interp_requests) {
+  if (shared_stub_to_interp_requests->is_empty()) {
+    return true;
+  }
+  auto by_shared_method = [](SharedStubToInterpRequest* r1, SharedStubToInterpRequest* r2) {
+    if (r1->shared_method() < r2->shared_method()) {
+      return -1;
+    } else if (r1->shared_method() > r2->shared_method()) {
+      return 1;
+    } else {
+      return 0;
+    }
+  };
+  shared_stub_to_interp_requests->sort(by_shared_method);
   MacroAssembler masm(cb);
-  LinkedListIterator<SharedStubToInterpRequest> it(shared_stub_to_interp_requests.head());
-  SharedStubToInterpRequest* request = it.next();
   int relocations_created = 0;
-  while (request != NULL) {
+  for (int i = 0; i < shared_stub_to_interp_requests->length();) {
     address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
     if (stub == NULL) {
       ciEnv::current()->record_failure("CodeCache is full");
       return false;
     }
-    Method* method = request->shared_method();
+
+    Method* method = shared_stub_to_interp_requests->at(i).shared_method();
     do {
-      masm.relocate(static_stub_Relocation::spec(request->caller_pc()), relocate_format);
-      request = it.next();
+      masm.relocate(static_stub_Relocation::spec(shared_stub_to_interp_requests->at(i).caller_pc()), relocate_format);
+      ++i;
       ++relocations_created;
-    } while (request != NULL && request->shared_method() == method);
+    } while (i < shared_stub_to_interp_requests->length() && shared_stub_to_interp_requests->at(i).shared_method() == method);
     masm.emit_static_call_stub();
     masm.end_a_stub();
   }
 
   if (relocations_created > 1 && UseNewCode) {
-    tty->print_cr("Requests %d", (int)shared_stub_to_interp_requests.size());
+    tty->print_cr("Requests %d", (int)shared_stub_to_interp_requests->length());
     tty->print_cr("Saved %d", (relocations_created-1)*CompiledStaticCall::to_interp_stub_size());
   }
   return true;

From 580544dc44c38d9f9f2c5316d3a18cabd29a4d20 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Mon, 11 Apr 2022 19:42:57 +0000
Subject: [PATCH 09/19] Update test to have more static stubs

---
 .../sharedstubs/SharedStubToInterpTest.java   | 52 +++++++++++++------
 1 file changed, 36 insertions(+), 16 deletions(-)

diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
index d5232df30aea8..728ea4b2a3ba6 100644
--- a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -65,8 +65,10 @@ public static void main(String[] args) throws Exception {
         command.add("-XX:CompileCommand=compileonly," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=print," + testClassName + "::" + "test");
-        command.add("-XX:CompileCommand=exclude," + testClassName + "::" + "log");
-        command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "log");
+        command.add("-XX:CompileCommand=exclude," + testClassName + "::" + "log01");
+        command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "log01");
+        command.add("-XX:CompileCommand=exclude," + testClassName + "::" + "log02");
+        command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "log02");
         command.add(testClassName);
         command.add("a");
         command.add("b");
@@ -104,11 +106,17 @@ private static void checkOutput(OutputAnalyzer output) {
             throw new RuntimeException("Missing compiler output for the method 'test'");
         }
 
-        // Shared static stubs are put after Deopt Handler Code.
-        match = skipTo(iter, "{runtime_call DeoptimizationBlob}");
-        if (match == null) {
-            throw new RuntimeException("The start of Deopt Handler Code not found");
+        while (iter.hasNext()) {
+            String nextLine = iter.next();
+            if (nextLine.contains("{static_stub}")) {
+                // Static stubs must be created at the end of the Stub section.
+                throw new RuntimeException("Found {static_stub} before Deopt Handler Code");
+            } else if (nextLine.contains("{runtime_call DeoptimizationBlob}")) {
+                // Shared static stubs are put after Deopt Handler Code.
+                break;
+            }
         }
+
         int foundStaticStubs = 0;
         while (iter.hasNext()) {
             if (iter.next().contains("{static_stub}")) {
@@ -116,21 +124,25 @@ private static void checkOutput(OutputAnalyzer output) {
             }
         }
 
-        final int expectedStaticStubs = 1;
+        final int expectedStaticStubs = 2;
         if (foundStaticStubs != expectedStaticStubs) {
             throw new RuntimeException("Found static stubs: " + foundStaticStubs + "; Expected static stubs: " + expectedStaticStubs);
         }
     }
 
     public static class StaticMethodTest {
-        static void log(int i) {
+        static void log01(int i) {
+        }
+        static void log02(int i) {
         }
 
         static void test(int i, String[] args) {
             if (i % args.length == 0) {
-                log(i);
+                log01(i);
+                log02(i);
             } else {
-                log(i);
+                log01(i);
+                log02(i);
             }
         }
 
@@ -142,14 +154,18 @@ public static void main(String[] args) {
     }
 
     public static final class FinalClassTest {
-        void log(int i) {
+        void log01(int i) {
+        }
+        void log02(int i) {
         }
 
         void test(int i, String[] args) {
             if (i % args.length == 0) {
-                log(i);
+                log01(i);
+                log02(i);
             } else {
-                log(i);
+                log01(i);
+                log02(i);
             }
         }
 
@@ -162,14 +178,18 @@ public static void main(String[] args) {
     }
 
     public static class FinalMethodTest {
-        final void log(int i) {
+        final void log01(int i) {
+        }
+        final void log02(int i) {
         }
 
         void test(int i, String[] args) {
             if (i % args.length == 0) {
-                log(i);
+                log01(i);
+                log02(i);
             } else {
-                log(i);
+                log01(i);
+                log02(i);
             }
         }
 

From 600d3a9fd1a28543b09e7c649150f177869b3d89 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Mon, 11 Apr 2022 20:35:43 +0000
Subject: [PATCH 10/19] Fix memory leak found by gtest

---
 src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp               | 2 +-
 src/hotspot/share/asm/codeBuffer.cpp                         | 5 ++++-
 src/hotspot/share/asm/codeBuffer.hpp                         | 3 ++-
 src/hotspot/share/asm/codeBuffer.inline.hpp                  | 2 +-
 src/hotspot/share/runtime/globals.hpp                        | 2 +-
 .../jtreg/compiler/sharedstubs/SharedStubToInterpTest.java   | 2 +-
 6 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
index 78b69aecba06a..4257782fdc2cb 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.cpp
@@ -27,5 +27,5 @@
 #include "asm/macroAssembler.hpp"
 
 bool CodeBuffer::pd_finalize_stubs() {
-  return emit_shared_stubs_to_interp<MacroAssembler>(this, &_shared_stub_to_interp_requests);
+  return emit_shared_stubs_to_interp<MacroAssembler>(this, _shared_stub_to_interp_requests);
 }
diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index d5ef305fffd12..424bba7600bc7 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -988,8 +988,11 @@ void CodeBuffer::finalize_stubs() {
 }
 
 void CodeBuffer::shared_stub_to_interp_for(Method* method, address caller_pc) {
+  if (_shared_stub_to_interp_requests == NULL) {
+    _shared_stub_to_interp_requests = new SharedStubToInterpRequests();
+  }
   SharedStubToInterpRequest request(method, caller_pc);
-  _shared_stub_to_interp_requests.push(request);
+  _shared_stub_to_interp_requests->push(request);
   _finalize_stubs = true;
 }
 
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index 9160d11f7205d..4a0e2614b213a 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -433,7 +433,7 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
 
   address      _last_insn;      // used to merge consecutive memory barriers, loads or stores.
 
-  SharedStubToInterpRequests _shared_stub_to_interp_requests; // used to collect requests for shared iterpreter stubs
+  SharedStubToInterpRequests* _shared_stub_to_interp_requests; // used to collect requests for shared iterpreter stubs
   bool         _finalize_stubs; // Indicate if we need to finalize stubs to make CodeBuffer final.
 
 #ifndef PRODUCT
@@ -454,6 +454,7 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
     _overflow_arena  = NULL;
     _last_insn       = NULL;
     _finalize_stubs  = false;
+    _shared_stub_to_interp_requests = NULL;
 
 #ifndef PRODUCT
     _decode_begin    = NULL;
diff --git a/src/hotspot/share/asm/codeBuffer.inline.hpp b/src/hotspot/share/asm/codeBuffer.inline.hpp
index d0cbc4f971a9d..bcea4245dca40 100644
--- a/src/hotspot/share/asm/codeBuffer.inline.hpp
+++ b/src/hotspot/share/asm/codeBuffer.inline.hpp
@@ -31,7 +31,7 @@
 
 template <typename MacroAssembler, int relocate_format = 0>
 bool emit_shared_stubs_to_interp(CodeBuffer* cb, SharedStubToInterpRequests* shared_stub_to_interp_requests) {
-  if (shared_stub_to_interp_requests->is_empty()) {
+  if (shared_stub_to_interp_requests == NULL) {
     return true;
   }
   auto by_shared_method = [](SharedStubToInterpRequest* r1, SharedStubToInterpRequest* r2) {
diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
index fe4645be713eb..481141cf764b2 100644
--- a/src/hotspot/share/runtime/globals.hpp
+++ b/src/hotspot/share/runtime/globals.hpp
@@ -2054,7 +2054,7 @@ const intx ObjectAlignmentInBytes = 8;
                                                                             \
   develop(bool, TraceOptimizedUpcallStubs, false,                              \
                 "Trace optimized upcall stub generation")                      \
-  product(bool, UseSharedStubs, false, DIAGNOSTIC,                          \
+  product(bool, UseSharedStubs, true, DIAGNOSTIC,                          \
                 "Allow sharing stubs whether it is possible")               \
                                                                             \
 
diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
index 728ea4b2a3ba6..16ae2c46fc132 100644
--- a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -61,7 +61,7 @@ public static void main(String[] args) throws Exception {
             throw new RuntimeException("Unknown compiler: " + compiler);
         }
         command.add("-Xbatch");
-        command.add("-XX:+UseSharedStubs");
+        //command.add("-XX:+UseSharedStubs");
         command.add("-XX:CompileCommand=compileonly," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=print," + testClassName + "::" + "test");

From 2dd68c92d5fb6370b1178f8fc874de9b3b5609b9 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Mon, 11 Apr 2022 20:46:29 +0000
Subject: [PATCH 11/19] Fix x86 build failure

---
 src/hotspot/cpu/x86/codeBuffer_x86.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.cpp b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
index 1e6ef09003277..3c406ed1b198e 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.cpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.cpp
@@ -27,5 +27,5 @@
 #include "asm/macroAssembler.hpp"
 
 bool CodeBuffer::pd_finalize_stubs() {
-  return emit_shared_stubs_to_interp<MacroAssembler, Assembler::imm_operand>(this, &_shared_stub_to_interp_requests);
+  return emit_shared_stubs_to_interp<MacroAssembler, Assembler::imm_operand>(this, _shared_stub_to_interp_requests);
 }

From 0ca42b1ed82e3480e9fcd16b4af350159bf742f6 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 15 Apr 2022 15:43:29 +0000
Subject: [PATCH 12/19] Set UseSharedStubs to true for AArch64

---
 src/hotspot/cpu/aarch64/vm_version_aarch64.cpp             | 4 ++++
 src/hotspot/share/asm/codeBuffer.inline.hpp                | 7 -------
 src/hotspot/share/runtime/globals.hpp                      | 6 +++---
 .../jtreg/compiler/sharedstubs/SharedStubToInterpTest.java | 1 -
 4 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp b/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
index 63ba7efc0a502..077681b886aa2 100644
--- a/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
@@ -129,6 +129,10 @@ void VM_Version::initialize() {
     }
   }
 
+  if (FLAG_IS_DEFAULT(UseSharedStubs)) {
+    FLAG_SET_DEFAULT(UseSharedStubs, true);
+  }
+
   // Enable vendor specific features
 
   // Ampere eMAG
diff --git a/src/hotspot/share/asm/codeBuffer.inline.hpp b/src/hotspot/share/asm/codeBuffer.inline.hpp
index bcea4245dca40..ad19653af4052 100644
--- a/src/hotspot/share/asm/codeBuffer.inline.hpp
+++ b/src/hotspot/share/asm/codeBuffer.inline.hpp
@@ -45,7 +45,6 @@ bool emit_shared_stubs_to_interp(CodeBuffer* cb, SharedStubToInterpRequests* sha
   };
   shared_stub_to_interp_requests->sort(by_shared_method);
   MacroAssembler masm(cb);
-  int relocations_created = 0;
   for (int i = 0; i < shared_stub_to_interp_requests->length();) {
     address stub = masm.start_a_stub(CompiledStaticCall::to_interp_stub_size());
     if (stub == NULL) {
@@ -57,16 +56,10 @@ bool emit_shared_stubs_to_interp(CodeBuffer* cb, SharedStubToInterpRequests* sha
     do {
       masm.relocate(static_stub_Relocation::spec(shared_stub_to_interp_requests->at(i).caller_pc()), relocate_format);
       ++i;
-      ++relocations_created;
     } while (i < shared_stub_to_interp_requests->length() && shared_stub_to_interp_requests->at(i).shared_method() == method);
     masm.emit_static_call_stub();
     masm.end_a_stub();
   }
-
-  if (relocations_created > 1 && UseNewCode) {
-    tty->print_cr("Requests %d", (int)shared_stub_to_interp_requests->length());
-    tty->print_cr("Saved %d", (relocations_created-1)*CompiledStaticCall::to_interp_stub_size());
-  }
   return true;
 }
 
diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
index 481141cf764b2..d937729a24bfd 100644
--- a/src/hotspot/share/runtime/globals.hpp
+++ b/src/hotspot/share/runtime/globals.hpp
@@ -2052,9 +2052,9 @@ const intx ObjectAlignmentInBytes = 8;
              "Mark all threads after a safepoint, and clear on a modify "   \
              "fence. Add cleanliness checks.")                              \
                                                                             \
-  develop(bool, TraceOptimizedUpcallStubs, false,                              \
-                "Trace optimized upcall stub generation")                      \
-  product(bool, UseSharedStubs, true, DIAGNOSTIC,                          \
+  develop(bool, TraceOptimizedUpcallStubs, false,                           \
+                "Trace optimized upcall stub generation")                   \
+  product(bool, UseSharedStubs, false, DIAGNOSTIC,                          \
                 "Allow sharing stubs whether it is possible")               \
                                                                             \
 
diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
index 16ae2c46fc132..acd64832ed3eb 100644
--- a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -61,7 +61,6 @@ public static void main(String[] args) throws Exception {
             throw new RuntimeException("Unknown compiler: " + compiler);
         }
         command.add("-Xbatch");
-        //command.add("-XX:+UseSharedStubs");
         command.add("-XX:CompileCommand=compileonly," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=print," + testClassName + "::" + "test");

From ec62db17c3e9f873046a31d7ea8925ad44ffe504 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 15 Apr 2022 22:05:25 +0000
Subject: [PATCH 13/19] Set UseSharedStubs to true for X86

---
 src/hotspot/cpu/x86/vm_version_x86.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/hotspot/cpu/x86/vm_version_x86.cpp b/src/hotspot/cpu/x86/vm_version_x86.cpp
index 41a43c7de3c97..27b5cdb4df571 100644
--- a/src/hotspot/cpu/x86/vm_version_x86.cpp
+++ b/src/hotspot/cpu/x86/vm_version_x86.cpp
@@ -2056,6 +2056,10 @@ void VM_Version::initialize() {
   detect_virt_stub = CAST_TO_FN_PTR(detect_virt_stub_t,
                                      g.generate_detect_virt());
 
+  if (FLAG_IS_DEFAULT(UseSharedStubs)) {
+    FLAG_SET_DEFAULT(UseSharedStubs, true);
+  }
+
   get_processor_features();
 
   LP64_ONLY(Assembler::precompute_instructions();)

From 04a7cc76044d045765e20dfa067762ad2c4c633a Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Wed, 20 Apr 2022 15:09:08 +0000
Subject: [PATCH 14/19] Update copyright year and add Unimplemented guards

---
 src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp | 2 +-
 src/hotspot/cpu/arm/codeBuffer_arm.hpp         | 9 +++++++--
 src/hotspot/cpu/ppc/codeBuffer_ppc.hpp         | 9 +++++++--
 src/hotspot/cpu/riscv/codeBuffer_riscv.hpp     | 9 +++++++--
 src/hotspot/cpu/s390/codeBuffer_s390.hpp       | 9 +++++++--
 src/hotspot/cpu/x86/codeBuffer_x86.hpp         | 2 +-
 src/hotspot/cpu/x86/compiledIC_x86.cpp         | 2 +-
 src/hotspot/cpu/zero/codeBuffer_zero.hpp       | 9 +++++++--
 src/hotspot/share/asm/codeBuffer.hpp           | 2 +-
 9 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
index 104eeccc7a1eb..02d6a496a0457 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2022, 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.
  *
diff --git a/src/hotspot/cpu/arm/codeBuffer_arm.hpp b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
index 375428ca86eeb..d561958561ed0 100644
--- a/src/hotspot/cpu/arm/codeBuffer_arm.hpp
+++ b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2022, 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
@@ -27,7 +27,12 @@
 
 private:
   void pd_initialize() {}
-  bool pd_finalize_stubs() { return true; }
+  bool pd_finalize_stubs() {
+    if (_finalize_stubs) {
+      Unimplemented();
+    }
+    return true;
+  }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
diff --git a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
index a71b573381745..119a39f2c0586 100644
--- a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
+++ b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2013 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -28,7 +28,12 @@
 
 private:
   void pd_initialize() {}
-  bool pd_finalize_stubs() { return true; }
+  bool pd_finalize_stubs() {
+    if (_finalize_stubs) {
+      Unimplemented();
+    }
+    return true;
+  }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
diff --git a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
index 7a69cf8c261b4..6ce43eb8c79cb 100644
--- a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
+++ b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
  * Copyright (c) 2020, 2021, Huawei Technologies Co., Ltd. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -29,7 +29,12 @@
 
 private:
   void pd_initialize() {}
-  bool pd_finalize_stubs() { return true; }
+  bool pd_finalize_stubs() {
+    if (_finalize_stubs) {
+      Unimplemented();
+    }
+    return true;
+  }
 
 public:
   void flush_bundle(bool start_new_bundle) {}
diff --git a/src/hotspot/cpu/s390/codeBuffer_s390.hpp b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
index 5dcd6c249db88..2f7518013c510 100644
--- a/src/hotspot/cpu/s390/codeBuffer_s390.hpp
+++ b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2016 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -28,7 +28,12 @@
 
  private:
   void pd_initialize() {}
-  bool pd_finalize_stubs() { return true; }
+  bool pd_finalize_stubs() {
+    if (_finalize_stubs) {
+      Unimplemented();
+    }
+    return true;
+  }
 
  public:
   void flush_bundle(bool start_new_bundle) {}
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.hpp b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
index 7a8fae033fd40..ef751e6198ec7 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.hpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2022, 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
diff --git a/src/hotspot/cpu/x86/compiledIC_x86.cpp b/src/hotspot/cpu/x86/compiledIC_x86.cpp
index d9d97d75033e0..b8ad469805ddc 100644
--- a/src/hotspot/cpu/x86/compiledIC_x86.cpp
+++ b/src/hotspot/cpu/x86/compiledIC_x86.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2022, 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
diff --git a/src/hotspot/cpu/zero/codeBuffer_zero.hpp b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
index 82831e51baaa1..67b15ecaaedb5 100644
--- a/src/hotspot/cpu/zero/codeBuffer_zero.hpp
+++ b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -28,6 +28,11 @@
 
  private:
   void pd_initialize() {}
-  bool pd_finalize_stubs() { return true; }
+  bool pd_finalize_stubs() {
+    if (_finalize_stubs) {
+      Unimplemented();
+    }
+    return true;
+  }
 
 #endif // CPU_ZERO_CODEBUFFER_ZERO_HPP
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index 4a0e2614b213a..132f7e0b281cb 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2022, 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

From 9051c0de60e437ed0ca3240e6adf96baebd184f9 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Thu, 21 Apr 2022 12:55:20 +0000
Subject: [PATCH 15/19] Make SharedStubToInterpRequest ResourceObj and set
 initial size of SharedStubToInterpRequests to 8

---
 src/hotspot/share/asm/codeBuffer.cpp | 2 +-
 src/hotspot/share/asm/codeBuffer.hpp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index 424bba7600bc7..22827e7e7eef5 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -989,7 +989,7 @@ void CodeBuffer::finalize_stubs() {
 
 void CodeBuffer::shared_stub_to_interp_for(Method* method, address caller_pc) {
   if (_shared_stub_to_interp_requests == NULL) {
-    _shared_stub_to_interp_requests = new SharedStubToInterpRequests();
+    _shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
   }
   SharedStubToInterpRequest request(method, caller_pc);
   _shared_stub_to_interp_requests->push(request);
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index 132f7e0b281cb..71fb39d8f3355 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -347,7 +347,7 @@ class Scrubber {
 // Calls of Java mehtods need stubs to the interpreter. Calls sharing the same Java method
 // can share a stub to interpreter.
 // A SharedStubToInterpRequest describes a request for a shared stub to the interpreter.
-class SharedStubToInterpRequest {
+class SharedStubToInterpRequest: public ResourceObj {
  private:
   Method* _shared_method;
   address _caller_pc;

From 1459e112b63cce2ad462f3366e0b6d3c8b315e26 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 22 Apr 2022 12:51:22 +0000
Subject: [PATCH 16/19] Remove UseSharedStubs and clarify shared stub use cases

---
 src/hotspot/cpu/aarch64/aarch64.ad             |  9 ++++-----
 src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp |  1 +
 src/hotspot/cpu/aarch64/vm_version_aarch64.cpp |  4 ----
 src/hotspot/cpu/arm/codeBuffer_arm.hpp         |  1 +
 src/hotspot/cpu/ppc/codeBuffer_ppc.hpp         |  1 +
 src/hotspot/cpu/riscv/codeBuffer_riscv.hpp     |  1 +
 src/hotspot/cpu/s390/codeBuffer_s390.hpp       |  1 +
 src/hotspot/cpu/x86/codeBuffer_x86.hpp         |  1 +
 src/hotspot/cpu/x86/vm_version_x86.cpp         |  4 ----
 src/hotspot/cpu/x86/x86_32.ad                  |  7 +++----
 src/hotspot/cpu/x86/x86_64.ad                  |  7 +++----
 src/hotspot/cpu/zero/codeBuffer_zero.hpp       |  2 ++
 src/hotspot/share/asm/codeBuffer.cpp           |  4 ++--
 src/hotspot/share/asm/codeBuffer.hpp           | 11 ++++++-----
 src/hotspot/share/asm/codeBuffer.inline.hpp    |  2 +-
 src/hotspot/share/c1/c1_LIRAssembler.cpp       | 14 ++++----------
 src/hotspot/share/runtime/globals.hpp          |  3 ---
 17 files changed, 31 insertions(+), 42 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/aarch64.ad b/src/hotspot/cpu/aarch64/aarch64.ad
index d3aa95a0f82a2..d496bc00ee61b 100644
--- a/src/hotspot/cpu/aarch64/aarch64.ad
+++ b/src/hotspot/cpu/aarch64/aarch64.ad
@@ -3810,11 +3810,10 @@ encode %{
         ciEnv::current()->record_failure("CodeCache is full");
         return;
       }
-      if (UseSharedStubs && _method->is_loaded() &&
-          (!_optimized_virtual || _method->is_final_method())) {
-        // Postpone creating a stub to the interpreter because
-        // it might be shared among calls of the same Java method.
-        cbuf.shared_stub_to_interp_for(_method->get_Method(), cbuf.insts_mark());
+      if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
+        // Calls of the same statically bound method can share
+        // a stub to the interpreter.
+        cbuf.shared_stub_to_interp_for(_method, cbuf.insts_mark());
       } else {
         // Emit stub for static call
         address stub = CompiledStaticCall::emit_to_interp_stub(cbuf);
diff --git a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
index 02d6a496a0457..f6b1241d4f187 100644
--- a/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/codeBuffer_aarch64.hpp
@@ -32,5 +32,6 @@
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static constexpr bool supports_shared_stubs() { return true; }
 
 #endif // CPU_AARCH64_CODEBUFFER_AARCH64_HPP
diff --git a/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp b/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
index 077681b886aa2..63ba7efc0a502 100644
--- a/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
@@ -129,10 +129,6 @@ void VM_Version::initialize() {
     }
   }
 
-  if (FLAG_IS_DEFAULT(UseSharedStubs)) {
-    FLAG_SET_DEFAULT(UseSharedStubs, true);
-  }
-
   // Enable vendor specific features
 
   // Ampere eMAG
diff --git a/src/hotspot/cpu/arm/codeBuffer_arm.hpp b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
index d561958561ed0..eefedb12e08cc 100644
--- a/src/hotspot/cpu/arm/codeBuffer_arm.hpp
+++ b/src/hotspot/cpu/arm/codeBuffer_arm.hpp
@@ -36,5 +36,6 @@
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static constexpr bool supports_shared_stubs() { return false; }
 
 #endif // CPU_ARM_CODEBUFFER_ARM_HPP
diff --git a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
index 119a39f2c0586..935063afb2f36 100644
--- a/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
+++ b/src/hotspot/cpu/ppc/codeBuffer_ppc.hpp
@@ -37,5 +37,6 @@
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static constexpr bool supports_shared_stubs() { return false; }
 
 #endif // CPU_PPC_CODEBUFFER_PPC_HPP
diff --git a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
index 6ce43eb8c79cb..2786d4ad76b41 100644
--- a/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
+++ b/src/hotspot/cpu/riscv/codeBuffer_riscv.hpp
@@ -38,5 +38,6 @@
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static constexpr bool supports_shared_stubs() { return false; }
 
 #endif // CPU_RISCV_CODEBUFFER_RISCV_HPP
diff --git a/src/hotspot/cpu/s390/codeBuffer_s390.hpp b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
index 2f7518013c510..dbb75f5a78c3d 100644
--- a/src/hotspot/cpu/s390/codeBuffer_s390.hpp
+++ b/src/hotspot/cpu/s390/codeBuffer_s390.hpp
@@ -39,5 +39,6 @@
   void flush_bundle(bool start_new_bundle) {}
 
   void getCpuData(const CodeBuffer * const cb) {}
+  static constexpr bool supports_shared_stubs() { return false; }
 
 #endif // CPU_S390_CODEBUFFER_S390_HPP
diff --git a/src/hotspot/cpu/x86/codeBuffer_x86.hpp b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
index ef751e6198ec7..3c6e6675b05a4 100644
--- a/src/hotspot/cpu/x86/codeBuffer_x86.hpp
+++ b/src/hotspot/cpu/x86/codeBuffer_x86.hpp
@@ -31,5 +31,6 @@
 
 public:
   void flush_bundle(bool start_new_bundle) {}
+  static constexpr bool supports_shared_stubs() { return true; }
 
 #endif // CPU_X86_CODEBUFFER_X86_HPP
diff --git a/src/hotspot/cpu/x86/vm_version_x86.cpp b/src/hotspot/cpu/x86/vm_version_x86.cpp
index 27b5cdb4df571..41a43c7de3c97 100644
--- a/src/hotspot/cpu/x86/vm_version_x86.cpp
+++ b/src/hotspot/cpu/x86/vm_version_x86.cpp
@@ -2056,10 +2056,6 @@ void VM_Version::initialize() {
   detect_virt_stub = CAST_TO_FN_PTR(detect_virt_stub_t,
                                      g.generate_detect_virt());
 
-  if (FLAG_IS_DEFAULT(UseSharedStubs)) {
-    FLAG_SET_DEFAULT(UseSharedStubs, true);
-  }
-
   get_processor_features();
 
   LP64_ONLY(Assembler::precompute_instructions();)
diff --git a/src/hotspot/cpu/x86/x86_32.ad b/src/hotspot/cpu/x86/x86_32.ad
index bffabf0228fd7..97428d26be9c5 100644
--- a/src/hotspot/cpu/x86/x86_32.ad
+++ b/src/hotspot/cpu/x86/x86_32.ad
@@ -1814,10 +1814,9 @@ encode %{
                      rspec, RELOC_DISP32);
       __ post_call_nop();
       address mark = cbuf.insts_mark();
-      if (UseSharedStubs && _method->is_loaded() &&
-          (!_optimized_virtual || _method->is_final_method())) {
-        // Postpone creating a stub to the interpreter because
-        // it might be shared among calls of the same Java method.
+      if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
+        // Calls of the same statically bound method can share
+        // a stub to the interpreter.
         cbuf.shared_stub_to_interp_for(_method->get_Method(), mark);
       } else {
         // Emit stubs for static call.
diff --git a/src/hotspot/cpu/x86/x86_64.ad b/src/hotspot/cpu/x86/x86_64.ad
index c143c2a33add5..a3b92844931ac 100644
--- a/src/hotspot/cpu/x86/x86_64.ad
+++ b/src/hotspot/cpu/x86/x86_64.ad
@@ -2169,10 +2169,9 @@ encode %{
       emit_d32_reloc(cbuf, (int) ($meth$$method - ((intptr_t) cbuf.insts_end()) - 4),
                      rspec, RELOC_DISP32);
       address mark = cbuf.insts_mark();
-      if (UseSharedStubs && _method->is_loaded() &&
-          (!_optimized_virtual || _method->is_final_method())) {
-        // Postpone creating a stub to the interpreter because
-        // it might be shared among calls of the same Java method.
+      if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
+        // Calls of the same statically bound method can share
+        // a stub to the interpreter.
         cbuf.shared_stub_to_interp_for(_method->get_Method(), mark);
       } else {
         // Emit stubs for static call.
diff --git a/src/hotspot/cpu/zero/codeBuffer_zero.hpp b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
index 67b15ecaaedb5..4d314f947ee02 100644
--- a/src/hotspot/cpu/zero/codeBuffer_zero.hpp
+++ b/src/hotspot/cpu/zero/codeBuffer_zero.hpp
@@ -34,5 +34,7 @@
     }
     return true;
   }
+ public:
+  static constexpr bool supports_shared_stubs() { return false; }
 
 #endif // CPU_ZERO_CODEBUFFER_ZERO_HPP
diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index 22827e7e7eef5..9cce29be7c1c6 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -987,11 +987,11 @@ void CodeBuffer::finalize_stubs() {
   _finalize_stubs = false;
 }
 
-void CodeBuffer::shared_stub_to_interp_for(Method* method, address caller_pc) {
+void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, address caller_pc) {
   if (_shared_stub_to_interp_requests == NULL) {
     _shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
   }
-  SharedStubToInterpRequest request(method, caller_pc);
+  SharedStubToInterpRequest request(callee, caller_pc);
   _shared_stub_to_interp_requests->push(request);
   _finalize_stubs = true;
 }
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index 71fb39d8f3355..bbe2f10ae6e40 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -37,6 +37,7 @@ class Compile;
 class BufferBlob;
 class CodeBuffer;
 class Label;
+class ciMethod;
 
 class CodeOffsets: public StackObj {
 public:
@@ -347,16 +348,16 @@ class Scrubber {
 // Calls of Java mehtods need stubs to the interpreter. Calls sharing the same Java method
 // can share a stub to interpreter.
 // A SharedStubToInterpRequest describes a request for a shared stub to the interpreter.
-class SharedStubToInterpRequest: public ResourceObj {
+class SharedStubToInterpRequest : public ResourceObj {
  private:
-  Method* _shared_method;
+  ciMethod* _shared_method;
   address _caller_pc;
 
  public:
-  SharedStubToInterpRequest(Method* method = NULL, address caller_pc = NULL) : _shared_method(method),
+  SharedStubToInterpRequest(ciMethod* method = NULL, address caller_pc = NULL) : _shared_method(method),
       _caller_pc(caller_pc) {}
 
-  Method* shared_method() const { return _shared_method; }
+  ciMethod* shared_method() const { return _shared_method; }
   address caller_pc() const { return _caller_pc; }
 };
 typedef GrowableArray<SharedStubToInterpRequest> SharedStubToInterpRequests;
@@ -710,7 +711,7 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
   void finalize_stubs();
 
   // Request for a shared stub to the interpreter
-  void shared_stub_to_interp_for(Method* call, address caller_pc);
+  void shared_stub_to_interp_for(ciMethod* callee, address caller_pc);
 
 #ifndef PRODUCT
  public:
diff --git a/src/hotspot/share/asm/codeBuffer.inline.hpp b/src/hotspot/share/asm/codeBuffer.inline.hpp
index ad19653af4052..d137bd893c53d 100644
--- a/src/hotspot/share/asm/codeBuffer.inline.hpp
+++ b/src/hotspot/share/asm/codeBuffer.inline.hpp
@@ -52,7 +52,7 @@ bool emit_shared_stubs_to_interp(CodeBuffer* cb, SharedStubToInterpRequests* sha
       return false;
     }
 
-    Method* method = shared_stub_to_interp_requests->at(i).shared_method();
+    ciMethod* method = shared_stub_to_interp_requests->at(i).shared_method();
     do {
       masm.relocate(static_stub_Relocation::spec(shared_stub_to_interp_requests->at(i).caller_pc()), relocate_format);
       ++i;
diff --git a/src/hotspot/share/c1/c1_LIRAssembler.cpp b/src/hotspot/share/c1/c1_LIRAssembler.cpp
index e3ad26194f274..f91dfd93715b3 100644
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp
@@ -449,22 +449,16 @@ void LIR_Assembler::emit_rtcall(LIR_OpRTCall* op) {
   rt_call(op->result_opr(), op->addr(), op->arguments(), op->tmp(), op->info());
 }
 
-static bool can_use_shared_stub_for(LIR_OpJavaCall* op) {
-  return UseSharedStubs &&
-         op->method()->is_loaded() &&
-         (op->code() == lir_static_call || op->method()->is_final_method());
-}
-
 void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {
   verify_oop_map(op->info());
 
   // must align calls sites, otherwise they can't be updated atomically
   align_call(op->code());
 
-  if (can_use_shared_stub_for(op)) {
-    // Postpone creating a stub to the interpreter.
-    // It might be shared among calls of the same Java method.
-    _masm->code()->shared_stub_to_interp_for(op->method()->get_Method(), pc());
+  if (CodeBuffer::supports_shared_stubs() && op->method()->can_be_statically_bound()) {
+    // Calls of the same statically bound method can share
+    // a stub to the interpreter.
+    _masm->code()->shared_stub_to_interp_for(op->method(), pc());
   } else {
     emit_static_call_stub();
   }
diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
index d937729a24bfd..2c620ab9ef36a 100644
--- a/src/hotspot/share/runtime/globals.hpp
+++ b/src/hotspot/share/runtime/globals.hpp
@@ -2054,9 +2054,6 @@ const intx ObjectAlignmentInBytes = 8;
                                                                             \
   develop(bool, TraceOptimizedUpcallStubs, false,                           \
                 "Trace optimized upcall stub generation")                   \
-  product(bool, UseSharedStubs, false, DIAGNOSTIC,                          \
-                "Allow sharing stubs whether it is possible")               \
-                                                                            \
 
 // end of RUNTIME_FLAGS
 

From 80ca8022778125096ce4637ad09d84a9a79257c4 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 22 Apr 2022 13:06:42 +0000
Subject: [PATCH 17/19] Fix x86 build failures

---
 src/hotspot/cpu/x86/x86_32.ad | 2 +-
 src/hotspot/cpu/x86/x86_64.ad | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/hotspot/cpu/x86/x86_32.ad b/src/hotspot/cpu/x86/x86_32.ad
index 97428d26be9c5..2eecc0658f40c 100644
--- a/src/hotspot/cpu/x86/x86_32.ad
+++ b/src/hotspot/cpu/x86/x86_32.ad
@@ -1817,7 +1817,7 @@ encode %{
       if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
         // Calls of the same statically bound method can share
         // a stub to the interpreter.
-        cbuf.shared_stub_to_interp_for(_method->get_Method(), mark);
+        cbuf.shared_stub_to_interp_for(_method, mark);
       } else {
         // Emit stubs for static call.
         address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);
diff --git a/src/hotspot/cpu/x86/x86_64.ad b/src/hotspot/cpu/x86/x86_64.ad
index a3b92844931ac..a58efd4898699 100644
--- a/src/hotspot/cpu/x86/x86_64.ad
+++ b/src/hotspot/cpu/x86/x86_64.ad
@@ -2172,7 +2172,7 @@ encode %{
       if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
         // Calls of the same statically bound method can share
         // a stub to the interpreter.
-        cbuf.shared_stub_to_interp_for(_method->get_Method(), mark);
+        cbuf.shared_stub_to_interp_for(_method, mark);
       } else {
         // Emit stubs for static call.
         address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);

From af4bc5eff16fd41d251d5b8782f2af51749d84ce Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 22 Apr 2022 13:45:53 +0000
Subject: [PATCH 18/19] Simplify test

---
 .../sharedstubs/SharedStubToInterpTest.java   | 64 +++++++++----------
 1 file changed, 31 insertions(+), 33 deletions(-)

diff --git a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
index acd64832ed3eb..a461c6935c49b 100644
--- a/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
+++ b/test/hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java
@@ -30,36 +30,25 @@
  *
  * @requires os.arch=="amd64" | os.arch=="x86_64" | os.arch=="i386" | os.arch=="x86" | os.arch=="aarch64"
  *
- * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 StaticMethodTest
- * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 StaticMethodTest
- * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 FinalClassTest
- * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 FinalClassTest
- * @run driver compiler.sharedstubs.SharedStubToInterpTest c2 FinalMethodTest
- * @run driver compiler.sharedstubs.SharedStubToInterpTest c1 FinalMethodTest
+ * @run driver compiler.sharedstubs.SharedStubToInterpTest
  */
 
 package compiler.sharedstubs;
 
 import java.util.ArrayList;
 import java.util.Iterator;
-import java.util.ListIterator;
+import java.util.List;
 import jdk.test.lib.process.OutputAnalyzer;
 import jdk.test.lib.process.ProcessTools;
 
 public class SharedStubToInterpTest {
-    public static void main(String[] args) throws Exception {
-        String compiler = args[0];
-        String testClassName = SharedStubToInterpTest.class.getName() + "$" + args[1];
+    private final static int ITERATIONS_TO_HEAT_LOOP = 20_000;
+
+    private static void runTest(String compiler, String test) throws Exception {
+        String testClassName = SharedStubToInterpTest.class.getName() + "$" + test;
         ArrayList<String> command = new ArrayList<String>();
-        command.add("-XX:+IgnoreUnrecognizedVMOptions");
+        command.add(compiler);
         command.add("-XX:+UnlockDiagnosticVMOptions");
-        if (compiler.equals("c2")) {
-            command.add("-XX:-TieredCompilation");
-        } else if (compiler.equals("c1")) {
-            command.add("-XX:TieredStopAtLevel=1");
-        } else {
-            throw new RuntimeException("Unknown compiler: " + compiler);
-        }
         command.add("-Xbatch");
         command.add("-XX:CompileCommand=compileonly," + testClassName + "::" + "test");
         command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "test");
@@ -69,9 +58,6 @@ public static void main(String[] args) throws Exception {
         command.add("-XX:CompileCommand=exclude," + testClassName + "::" + "log02");
         command.add("-XX:CompileCommand=dontinline," + testClassName + "::" + "log02");
         command.add(testClassName);
-        command.add("a");
-        command.add("b");
-        command.add("c");
 
         ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(command);
 
@@ -84,6 +70,18 @@ public static void main(String[] args) throws Exception {
         checkOutput(analyzer);
     }
 
+    public static void main(String[] args) throws Exception {
+        List<String> compilers = java.util.Arrays.asList("-XX:-TieredCompilation" /* C2 */,
+            "-XX:TieredStopAtLevel=1" /* C1 */);
+        List<String> tests = java.util.Arrays.asList("StaticMethodTest",
+            "FinalClassTest", "FinalMethodTest");
+        for (String compiler : compilers) {
+            for (String test : tests) {
+                runTest(compiler, test);
+            }
+        }
+    }
+
     private static String skipTo(Iterator<String> iter, String substring) {
         while (iter.hasNext()) {
             String nextLine = iter.next();
@@ -135,8 +133,8 @@ static void log01(int i) {
         static void log02(int i) {
         }
 
-        static void test(int i, String[] args) {
-            if (i % args.length == 0) {
+        static void test(int i) {
+            if (i % 3 == 0) {
                 log01(i);
                 log02(i);
             } else {
@@ -146,8 +144,8 @@ static void test(int i, String[] args) {
         }
 
         public static void main(String[] args) {
-            for (int i = 1; i < 50_000; ++i) {
-                test(i, args);
+            for (int i = 1; i < ITERATIONS_TO_HEAT_LOOP; ++i) {
+                test(i);
             }
         }
     }
@@ -158,8 +156,8 @@ void log01(int i) {
         void log02(int i) {
         }
 
-        void test(int i, String[] args) {
-            if (i % args.length == 0) {
+        void test(int i) {
+            if (i % 3 == 0) {
                 log01(i);
                 log02(i);
             } else {
@@ -170,8 +168,8 @@ void test(int i, String[] args) {
 
         public static void main(String[] args) {
             FinalClassTest tFC = new FinalClassTest();
-            for (int i = 1; i < 50_000; ++i) {
-                tFC.test(i,args);
+            for (int i = 1; i < ITERATIONS_TO_HEAT_LOOP; ++i) {
+                tFC.test(i);
             }
         }
     }
@@ -182,8 +180,8 @@ final void log01(int i) {
         final void log02(int i) {
         }
 
-        void test(int i, String[] args) {
-            if (i % args.length == 0) {
+        void test(int i) {
+            if (i % 3 == 0) {
                 log01(i);
                 log02(i);
             } else {
@@ -194,8 +192,8 @@ void test(int i, String[] args) {
 
         public static void main(String[] args) {
             FinalMethodTest tFM = new FinalMethodTest();
-            for (int i = 1; i < 50_000; ++i) {
-                tFM.test(i,args);
+            for (int i = 1; i < ITERATIONS_TO_HEAT_LOOP; ++i) {
+                tFM.test(i);
             }
         }
     }

From a249f7da85adededccf1b3e3076d56a316ceee96 Mon Sep 17 00:00:00 2001
From: Evgeny Astigeevich <eastig@amazon.com>
Date: Fri, 20 May 2022 14:50:45 +0000
Subject: [PATCH 19/19] Use call offset instead of caller pc

---
 src/hotspot/cpu/aarch64/aarch64.ad          |  2 +-
 src/hotspot/cpu/x86/x86_32.ad               |  2 +-
 src/hotspot/cpu/x86/x86_64.ad               |  2 +-
 src/hotspot/share/asm/codeBuffer.cpp        |  4 +--
 src/hotspot/share/asm/codeBuffer.hpp        | 36 +++++++++++----------
 src/hotspot/share/asm/codeBuffer.inline.hpp |  3 +-
 src/hotspot/share/c1/c1_LIRAssembler.cpp    |  3 +-
 7 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/src/hotspot/cpu/aarch64/aarch64.ad b/src/hotspot/cpu/aarch64/aarch64.ad
index d496bc00ee61b..8afaa044da1b1 100644
--- a/src/hotspot/cpu/aarch64/aarch64.ad
+++ b/src/hotspot/cpu/aarch64/aarch64.ad
@@ -3813,7 +3813,7 @@ encode %{
       if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
         // Calls of the same statically bound method can share
         // a stub to the interpreter.
-        cbuf.shared_stub_to_interp_for(_method, cbuf.insts_mark());
+        cbuf.shared_stub_to_interp_for(_method, cbuf.insts()->mark_off());
       } else {
         // Emit stub for static call
         address stub = CompiledStaticCall::emit_to_interp_stub(cbuf);
diff --git a/src/hotspot/cpu/x86/x86_32.ad b/src/hotspot/cpu/x86/x86_32.ad
index 2eecc0658f40c..09c6c278e2fed 100644
--- a/src/hotspot/cpu/x86/x86_32.ad
+++ b/src/hotspot/cpu/x86/x86_32.ad
@@ -1817,7 +1817,7 @@ encode %{
       if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
         // Calls of the same statically bound method can share
         // a stub to the interpreter.
-        cbuf.shared_stub_to_interp_for(_method, mark);
+        cbuf.shared_stub_to_interp_for(_method, cbuf.insts()->mark_off());
       } else {
         // Emit stubs for static call.
         address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);
diff --git a/src/hotspot/cpu/x86/x86_64.ad b/src/hotspot/cpu/x86/x86_64.ad
index a58efd4898699..ac19bf333f009 100644
--- a/src/hotspot/cpu/x86/x86_64.ad
+++ b/src/hotspot/cpu/x86/x86_64.ad
@@ -2172,7 +2172,7 @@ encode %{
       if (CodeBuffer::supports_shared_stubs() && _method->can_be_statically_bound()) {
         // Calls of the same statically bound method can share
         // a stub to the interpreter.
-        cbuf.shared_stub_to_interp_for(_method, mark);
+        cbuf.shared_stub_to_interp_for(_method, cbuf.insts()->mark_off());
       } else {
         // Emit stubs for static call.
         address stub = CompiledStaticCall::emit_to_interp_stub(cbuf, mark);
diff --git a/src/hotspot/share/asm/codeBuffer.cpp b/src/hotspot/share/asm/codeBuffer.cpp
index 9cce29be7c1c6..6cf1fec599e92 100644
--- a/src/hotspot/share/asm/codeBuffer.cpp
+++ b/src/hotspot/share/asm/codeBuffer.cpp
@@ -987,11 +987,11 @@ void CodeBuffer::finalize_stubs() {
   _finalize_stubs = false;
 }
 
-void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, address caller_pc) {
+void CodeBuffer::shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset) {
   if (_shared_stub_to_interp_requests == NULL) {
     _shared_stub_to_interp_requests = new SharedStubToInterpRequests(8);
   }
-  SharedStubToInterpRequest request(callee, caller_pc);
+  SharedStubToInterpRequest request(callee, call_offset);
   _shared_stub_to_interp_requests->push(request);
   _finalize_stubs = true;
 }
diff --git a/src/hotspot/share/asm/codeBuffer.hpp b/src/hotspot/share/asm/codeBuffer.hpp
index bbe2f10ae6e40..ca9d0c641a0aa 100644
--- a/src/hotspot/share/asm/codeBuffer.hpp
+++ b/src/hotspot/share/asm/codeBuffer.hpp
@@ -38,6 +38,7 @@ class BufferBlob;
 class CodeBuffer;
 class Label;
 class ciMethod;
+class SharedStubToInterpRequest;
 
 class CodeOffsets: public StackObj {
 public:
@@ -344,22 +345,6 @@ class Scrubber {
 };
 #endif // ASSERT
 
-// A Java method can have calls of Java methods which can be statically bound.
-// Calls of Java mehtods need stubs to the interpreter. Calls sharing the same Java method
-// can share a stub to interpreter.
-// A SharedStubToInterpRequest describes a request for a shared stub to the interpreter.
-class SharedStubToInterpRequest : public ResourceObj {
- private:
-  ciMethod* _shared_method;
-  address _caller_pc;
-
- public:
-  SharedStubToInterpRequest(ciMethod* method = NULL, address caller_pc = NULL) : _shared_method(method),
-      _caller_pc(caller_pc) {}
-
-  ciMethod* shared_method() const { return _shared_method; }
-  address caller_pc() const { return _caller_pc; }
-};
 typedef GrowableArray<SharedStubToInterpRequest> SharedStubToInterpRequests;
 
 // A CodeBuffer describes a memory space into which assembly
@@ -711,7 +696,7 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
   void finalize_stubs();
 
   // Request for a shared stub to the interpreter
-  void shared_stub_to_interp_for(ciMethod* callee, address caller_pc);
+  void shared_stub_to_interp_for(ciMethod* callee, csize_t call_offset);
 
 #ifndef PRODUCT
  public:
@@ -728,6 +713,23 @@ class CodeBuffer: public StackObj DEBUG_ONLY(COMMA private Scrubber) {
 
 };
 
+// A Java method can have calls of Java methods which can be statically bound.
+// Calls of Java methods need stubs to the interpreter. Calls sharing the same Java method
+// can share a stub to the interpreter.
+// A SharedStubToInterpRequest is a request for a shared stub to the interpreter.
+class SharedStubToInterpRequest : public ResourceObj {
+ private:
+  ciMethod* _shared_method;
+  CodeBuffer::csize_t _call_offset; // The offset of the call in CodeBuffer
+
+ public:
+  SharedStubToInterpRequest(ciMethod* method = NULL, CodeBuffer::csize_t call_offset = -1) : _shared_method(method),
+      _call_offset(call_offset) {}
+
+  ciMethod* shared_method() const { return _shared_method; }
+  CodeBuffer::csize_t call_offset() const { return _call_offset; }
+};
+
 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) {
   if (remaining() < amount) { _outer->expand(this, amount); return true; }
   return false;
diff --git a/src/hotspot/share/asm/codeBuffer.inline.hpp b/src/hotspot/share/asm/codeBuffer.inline.hpp
index d137bd893c53d..045cff13f25a2 100644
--- a/src/hotspot/share/asm/codeBuffer.inline.hpp
+++ b/src/hotspot/share/asm/codeBuffer.inline.hpp
@@ -54,7 +54,8 @@ bool emit_shared_stubs_to_interp(CodeBuffer* cb, SharedStubToInterpRequests* sha
 
     ciMethod* method = shared_stub_to_interp_requests->at(i).shared_method();
     do {
-      masm.relocate(static_stub_Relocation::spec(shared_stub_to_interp_requests->at(i).caller_pc()), relocate_format);
+      address caller_pc = cb->insts_begin() + shared_stub_to_interp_requests->at(i).call_offset();
+      masm.relocate(static_stub_Relocation::spec(caller_pc), relocate_format);
       ++i;
     } while (i < shared_stub_to_interp_requests->length() && shared_stub_to_interp_requests->at(i).shared_method() == method);
     masm.emit_static_call_stub();
diff --git a/src/hotspot/share/c1/c1_LIRAssembler.cpp b/src/hotspot/share/c1/c1_LIRAssembler.cpp
index f91dfd93715b3..1f286330dc6d3 100644
--- a/src/hotspot/share/c1/c1_LIRAssembler.cpp
+++ b/src/hotspot/share/c1/c1_LIRAssembler.cpp
@@ -458,7 +458,8 @@ void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {
   if (CodeBuffer::supports_shared_stubs() && op->method()->can_be_statically_bound()) {
     // Calls of the same statically bound method can share
     // a stub to the interpreter.
-    _masm->code()->shared_stub_to_interp_for(op->method(), pc());
+    CodeBuffer::csize_t call_offset = pc() - _masm->code()->insts_begin();
+    _masm->code()->shared_stub_to_interp_for(op->method(), call_offset);
   } else {
     emit_static_call_stub();
   }