8348858: [leyden] Bump the default code buffer sizes to store more generated code

src/hotspot/share/gc/g1/c2/g1BarrierSetC2.cpp

@@ -542,7 +542,7 @@ void G1BarrierSetC2::emit_stubs(CodeBuffer& cb) const {
   GrowableArray<G1BarrierStubC2*>* const stubs = barrier_set_state()->stubs();
   for (int i = 0; i < stubs->length(); i++) {
     // Make sure there is enough space in the code buffer
-    if (cb.insts()->maybe_expand_to_ensure_remaining(PhaseOutput::MAX_inst_gcstub_size) && cb.blob() == nullptr) {
+    if (cb.insts()->maybe_expand_to_ensure_remaining(PhaseOutput::max_inst_gcstub_size()) && cb.blob() == nullptr) {
       ciEnv::current()->record_failure("CodeCache is full");
       return;
     }

src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp

@@ -315,7 +315,7 @@ void ZBarrierSetC2::emit_stubs(CodeBuffer& cb) const {
 
   for (int i = 0; i < stubs->length(); i++) {
     // Make sure there is enough space in the code buffer
-    if (cb.insts()->maybe_expand_to_ensure_remaining(PhaseOutput::MAX_inst_gcstub_size) && cb.blob() == nullptr) {
+    if (cb.insts()->maybe_expand_to_ensure_remaining(PhaseOutput::max_inst_gcstub_size()) && cb.blob() == nullptr) {
       ciEnv::current()->record_failure("CodeCache is full");
       return;
     }

src/hotspot/share/opto/c2compiler.cpp

@@ -887,5 +887,5 @@ int C2Compiler::initial_code_buffer_size(int const_size) {
   // See Compile::init_scratch_buffer_blob
   int locs_size = sizeof(relocInfo) * PhaseOutput::MAX_locs_size;
   int slop = 2 * CodeSection::end_slop(); // space between sections
-  return PhaseOutput::MAX_inst_size + PhaseOutput::MAX_stubs_size + const_size + slop + locs_size;
+  return PhaseOutput::max_inst_size() + PhaseOutput::MAX_stubs_size + const_size + slop + locs_size;
 }

src/hotspot/share/opto/output.cpp

@@ -1370,7 +1370,7 @@ CodeBuffer* PhaseOutput::init_buffer() {
   int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
   int deopt_handler_req     = HandlerImpl::size_deopt_handler()     + MAX_stubs_size; // add marginal slop for handler
   stub_req += MAX_stubs_size;   // ensure per-stub margin
-  code_req += MAX_inst_size;    // ensure per-instruction margin
+  code_req += max_inst_size();  // ensure per-instruction margin
 
   if (StressCodeBuffers)
     code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10;  // force expansion
@@ -1567,7 +1567,7 @@ void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
           last_inst++;
           C->cfg()->map_node_to_block(nop, block);
           // Ensure enough space.
-          masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
+          masm->code()->insts()->maybe_expand_to_ensure_remaining(max_inst_size());
           if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
             C->record_failure("CodeCache is full");
             return;
@@ -1696,7 +1696,7 @@ void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
       }
 
       // Verify that there is sufficient space remaining
-      masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
+      masm->code()->insts()->maybe_expand_to_ensure_remaining(max_inst_size());
       if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
         C->record_failure("CodeCache is full");
         return;
@@ -3353,7 +3353,7 @@ uint PhaseOutput::scratch_emit_size(const Node* n) {
   // expensive, since it has to grab the code cache lock.
   BufferBlob* blob = this->scratch_buffer_blob();
   assert(blob != nullptr, "Initialize BufferBlob at start");
-  assert(blob->size() > MAX_inst_size, "sanity");
+  assert(blob->size() > max_inst_size(), "sanity");
   relocInfo* locs_buf = scratch_locs_memory();
   address blob_begin = blob->content_begin();
   address blob_end   = (address)locs_buf;
@@ -3667,3 +3667,17 @@ void PhaseOutput::print_statistics() {
   Scheduling::print_statistics();
 }
 #endif
+
+int PhaseOutput::max_inst_size() {
+  if (SCCache::is_on_for_write()) {
+    // See the comment in output.hpp.
+    return 16384;
+  } else {
+    return mainline_MAX_inst_size;
+  }
+}
+
+int PhaseOutput::max_inst_gcstub_size() {
+  assert(mainline_MAX_inst_size <= max_inst_size(), "Sanity");
+  return mainline_MAX_inst_size;
+}

src/hotspot/share/opto/output.hpp

@@ -185,23 +185,28 @@ class PhaseOutput : public Phase {
   // SCCache::write_nmethod bails when nmethod buffer is expanded.
   // Large methods would routinely expand the buffer, making themselves
   // ineligible for SCCache stores. In order to minimize this effect,
-  // we default to larger default sizes.
+  // we default to larger default sizes. We do this only when SCC dumping
+  // is active, to avoid impact on default configuration.
   //
   // Additionally, GC barrier stubs expand up to MAX_inst_size in mainline,
   // which also forced resizes often. Current code replaces it with
-  // MAX_inst_gcstub_size, which equals to old MAX_inst_size, so GC stubs
+  // max_inst_gcstub_size, which equals to old MAX_inst_size, so GC stubs
   // still fit nicely, and do not force the resizes too often.
   //
+  // The old enum is renamed, so direct misuse in new code from mainline would
+  // be caught as build failure.
+  //
   // TODO: Revert this back to mainline once SCCache is fixed.
   enum ScratchBufferBlob {
-    MAX_inst_size       = 16384,
-    MAX_inst_gcstub_size= 2048,
+    mainline_MAX_inst_size = 2048,
     MAX_locs_size       = 128, // number of relocInfo elements
     MAX_const_size      = 128,
     MAX_stubs_size      = 128
   };
 
-  static_assert(MAX_inst_gcstub_size <= MAX_inst_size, "sanity");
+  // Current uses of MAX_inst_size should be replaced with these getters:
+  static int max_inst_size();
+  static int max_inst_gcstub_size();
 
   int               frame_slots() const         { return _frame_slots; }
   int               frame_size_in_words() const; // frame_slots in units of the polymorphic 'words'