1 /*
  2  * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "memory/resourceArea.hpp"
 26 #include "opto/addnode.hpp"
 27 #include "opto/callnode.hpp"
 28 #include "opto/cfgnode.hpp"
 29 #include "opto/compile.hpp"
 30 #include "opto/convertnode.hpp"
 31 #include "opto/locknode.hpp"
 32 #include "opto/memnode.hpp"
 33 #include "opto/mulnode.hpp"
 34 #include "opto/node.hpp"
 35 #include "opto/parse.hpp"
 36 #include "opto/phaseX.hpp"
 37 #include "opto/rootnode.hpp"
 38 #include "opto/runtime.hpp"
 39 #include "opto/type.hpp"
 40 #include "runtime/stubRoutines.hpp"
 41 
 42 //--------------------gen_stub-------------------------------
 43 void GraphKit::gen_stub(address C_function,
 44                         const char *name,
 45                         int is_fancy_jump,
 46                         bool pass_tls,
 47                         bool return_pc) {
 48   ResourceMark rm;
 49 
 50   const TypeTuple *jdomain = C->tf()->domain();
 51   const TypeTuple *jrange  = C->tf()->range();
 52 
 53   // The procedure start
 54   StartNode* start = new StartNode(root(), jdomain);
 55   _gvn.set_type_bottom(start);
 56 
 57   // Make a map, with JVM state
 58   uint parm_cnt = jdomain->cnt();
 59   uint max_map = MAX2(2*parm_cnt+1, jrange->cnt());
 60   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
 61   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
 62   JVMState* jvms = new (C) JVMState(0);
 63   jvms->set_bci(InvocationEntryBci);
 64   jvms->set_monoff(max_map);
 65   jvms->set_scloff(max_map);
 66   jvms->set_endoff(max_map);
 67   {
 68     SafePointNode *map = new SafePointNode( max_map, jvms );
 69     jvms->set_map(map);
 70     set_jvms(jvms);
 71     assert(map == this->map(), "kit.map is set");
 72   }
 73 
 74   // Make up the parameters
 75   uint i;
 76   for (i = 0; i < parm_cnt; i++) {
 77     map()->init_req(i, _gvn.transform(new ParmNode(start, i)));
 78   }
 79   for ( ; i<map()->req(); i++) {
 80     map()->init_req(i, top());      // For nicer debugging
 81   }
 82 
 83   // GraphKit requires memory to be a MergeMemNode:
 84   set_all_memory(map()->memory());
 85 
 86   // Get base of thread-local storage area
 87   Node* thread = _gvn.transform(new ThreadLocalNode());
 88 
 89   const int NoAlias = Compile::AliasIdxBot;
 90 
 91   Node* adr_last_Java_pc = basic_plus_adr(top(),
 92                                             thread,
 93                                             in_bytes(JavaThread::frame_anchor_offset()) +
 94                                             in_bytes(JavaFrameAnchor::last_Java_pc_offset()));
 95 
 96   // Drop in the last_Java_sp.  last_Java_fp is not touched.
 97   // Always do this after the other "last_Java_frame" fields are set since
 98   // as soon as last_Java_sp != nullptr the has_last_Java_frame is true and
 99   // users will look at the other fields.
100   //
101   Node *adr_sp = basic_plus_adr(top(), thread, in_bytes(JavaThread::last_Java_sp_offset()));
102   Node *last_sp = frameptr();
103   store_to_memory(control(), adr_sp, last_sp, T_ADDRESS, MemNode::unordered);
104 
105   // Set _thread_in_native
106   // The order of stores into TLS is critical!  Setting _thread_in_native MUST
107   // be last, because a GC is allowed at any time after setting it and the GC
108   // will require last_Java_pc and last_Java_sp.
109 
110   //-----------------------------
111   // Compute signature for C call.  Varies from the Java signature!
112 
113   const Type **fields = TypeTuple::fields(2*parm_cnt+2);
114   uint cnt = TypeFunc::Parms;
115   // The C routines gets the base of thread-local storage passed in as an
116   // extra argument. Not all calls need it, but it is cheap to add here.
117   for (uint pcnt = cnt; pcnt < parm_cnt; pcnt++, cnt++) {
118     const Type *f = jdomain->field_at(pcnt);
119     if (CCallingConventionRequiresIntsAsLongs && f->isa_int()) {
120       fields[cnt++] = TypeLong::LONG;
121       fields[cnt] = Type::HALF; // Must add an additional half for a long.
122     } else {
123       fields[cnt] = f;
124     }
125   }
126   fields[cnt++] = TypeRawPtr::BOTTOM; // Thread-local storage
127   // Also pass in the caller's PC, if asked for.
128   if (return_pc) {
129     fields[cnt++] = TypeRawPtr::BOTTOM; // Return PC
130   }
131   const TypeTuple* domain = TypeTuple::make(cnt, fields);
132 
133   // The C routine we are about to call cannot return an oop; it can block on
134   // exit and a GC will trash the oop while it sits in C-land.  Instead, we
135   // return the oop through TLS for runtime calls.
136   // Also, C routines returning integer subword values leave the high
137   // order bits dirty; these must be cleaned up by explicit sign extension.
138   const Type* retval = (jrange->cnt() == TypeFunc::Parms) ? Type::TOP : jrange->field_at(TypeFunc::Parms);
139   // Make a private copy of jrange->fields();
140   const Type **rfields = TypeTuple::fields(jrange->cnt() - TypeFunc::Parms);
141   // Fixup oop returns
142   int retval_ptr = retval->isa_oop_ptr();
143   if (retval_ptr) {
144     assert( pass_tls, "Oop must be returned thru TLS" );
145     // Fancy-jumps return address; others return void
146     rfields[TypeFunc::Parms] = is_fancy_jump ? TypeRawPtr::BOTTOM : Type::TOP;
147 
148   } else if (retval->isa_int()) { // Returning any integer subtype?
149     // "Fatten" byte, char & short return types to 'int' to show that
150     // the native C code can return values with junk high order bits.
151     // We'll sign-extend it below later.
152     rfields[TypeFunc::Parms] = TypeInt::INT; // It's "dirty" and needs sign-ext
153 
154   } else if (jrange->cnt() >= TypeFunc::Parms+1) { // Else copy other types
155     rfields[TypeFunc::Parms] = jrange->field_at(TypeFunc::Parms);
156     if (jrange->cnt() == TypeFunc::Parms+2) {
157       rfields[TypeFunc::Parms+1] = jrange->field_at(TypeFunc::Parms+1);
158     }
159   }
160   const TypeTuple* range = TypeTuple::make(jrange->cnt(), rfields);
161 
162   // Final C signature
163   const TypeFunc *c_sig = TypeFunc::make(domain, range);
164 
165   //-----------------------------
166   // Make the call node.
167   CallRuntimeNode* call = new CallRuntimeNode(c_sig, C_function, name, TypePtr::BOTTOM, new (C) JVMState(0));
168   //-----------------------------
169 
170   // Fix-up the debug info for the call.
171   call->jvms()->set_bci(0);
172   call->jvms()->set_offsets(cnt);
173 
174   // Set fixed predefined input arguments.
175   cnt = 0;
176   for (i = 0; i < TypeFunc::Parms; i++) {
177     call->init_req(cnt++, map()->in(i));
178   }
179   // A little too aggressive on the parm copy; return address is not an input.
180   call->set_req(TypeFunc::ReturnAdr, top());
181   for (; i < parm_cnt; i++) { // Regular input arguments.
182     const Type *f = jdomain->field_at(i);
183     if (CCallingConventionRequiresIntsAsLongs && f->isa_int()) {
184       call->init_req(cnt++, _gvn.transform(new ConvI2LNode(map()->in(i))));
185       call->init_req(cnt++, top());
186     } else {
187       call->init_req(cnt++, map()->in(i));
188     }
189   }
190   call->init_req(cnt++, thread);
191   if (return_pc) {             // Return PC, if asked for.
192     call->init_req(cnt++, returnadr());
193   }
194 
195   _gvn.transform(call);
196 
197   //-----------------------------
198   // Now set up the return results
199   set_control( _gvn.transform( new ProjNode(call,TypeFunc::Control)) );
200   set_i_o(     _gvn.transform( new ProjNode(call,TypeFunc::I_O    )) );
201   set_all_memory_call(call);
202   if (range->cnt() > TypeFunc::Parms) {
203     Node* retnode = _gvn.transform( new ProjNode(call,TypeFunc::Parms) );
204     // C-land is allowed to return sub-word values.  Convert to integer type.
205     assert( retval != Type::TOP, "" );
206     if (retval == TypeInt::BOOL) {
207       retnode = _gvn.transform( new AndINode(retnode, intcon(0xFF)) );
208     } else if (retval == TypeInt::CHAR) {
209       retnode = _gvn.transform( new AndINode(retnode, intcon(0xFFFF)) );
210     } else if (retval == TypeInt::BYTE) {
211       retnode = _gvn.transform( new LShiftINode(retnode, intcon(24)) );
212       retnode = _gvn.transform( new RShiftINode(retnode, intcon(24)) );
213     } else if (retval == TypeInt::SHORT) {
214       retnode = _gvn.transform( new LShiftINode(retnode, intcon(16)) );
215       retnode = _gvn.transform( new RShiftINode(retnode, intcon(16)) );
216     }
217     map()->set_req( TypeFunc::Parms, retnode );
218   }
219 
220   //-----------------------------
221 
222   // Clear last_Java_sp
223   store_to_memory(control(), adr_sp, null(), T_ADDRESS, MemNode::unordered);
224   // Clear last_Java_pc
225   store_to_memory(control(), adr_last_Java_pc, null(), T_ADDRESS, MemNode::unordered);
226 
227   // For is-fancy-jump, the C-return value is also the branch target
228   Node* target = map()->in(TypeFunc::Parms);
229   // Runtime call returning oop in TLS?  Fetch it out
230   if( pass_tls ) {
231     Node* adr = basic_plus_adr(top(), thread, in_bytes(JavaThread::vm_result_offset()));
232     Node* vm_result = make_load(nullptr, adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered);
233     map()->set_req(TypeFunc::Parms, vm_result); // vm_result passed as result
234     // clear thread-local-storage(tls)
235     store_to_memory(control(), adr, null(), T_ADDRESS, MemNode::unordered);
236   }
237 
238   //-----------------------------
239   // check exception
240   Node* adr = basic_plus_adr(top(), thread, in_bytes(Thread::pending_exception_offset()));
241   Node* pending = make_load(nullptr, adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered);
242 
243   Node* exit_memory = reset_memory();
244 
245   Node* cmp = _gvn.transform( new CmpPNode(pending, null()) );
246   Node* bo  = _gvn.transform( new BoolNode(cmp, BoolTest::ne) );
247   IfNode   *iff = create_and_map_if(control(), bo, PROB_MIN, COUNT_UNKNOWN);
248 
249   Node* if_null     = _gvn.transform( new IfFalseNode(iff) );
250   Node* if_not_null = _gvn.transform( new IfTrueNode(iff)  );
251 
252   assert (StubRoutines::forward_exception_entry() != nullptr, "must be generated before");
253   Node *to_exc = new ForwardExceptionNode(if_not_null,
254                                           i_o(),
255                                           exit_memory,
256                                           frameptr(),
257                                           returnadr());
258   root()->add_req(_gvn.transform(to_exc));  // bind to root to keep live
259   C->verify_start(start);
260 
261   //-----------------------------
262   // If this is a normal subroutine return, issue the return and be done.
263   Node *ret = nullptr;
264   switch( is_fancy_jump ) {
265   case 0:                       // Make a return instruction
266     // Return to caller, free any space for return address
267     ret = new ReturnNode(TypeFunc::Parms, if_null,
268                          i_o(),
269                          exit_memory,
270                          frameptr(),
271                          returnadr());
272     if (C->tf()->range()->cnt() > TypeFunc::Parms)
273       ret->add_req( map()->in(TypeFunc::Parms) );
274     break;
275   case 1:    // This is a fancy tail-call jump.  Jump to computed address.
276     // Jump to new callee; leave old return address alone.
277     ret = new TailCallNode(if_null,
278                            i_o(),
279                            exit_memory,
280                            frameptr(),
281                            returnadr(),
282                            target, map()->in(TypeFunc::Parms));
283     break;
284   case 2:                       // Pop return address & jump
285     // Throw away old return address; jump to new computed address
286     //assert(C_function == CAST_FROM_FN_PTR(address, OptoRuntime::rethrow_C), "fancy_jump==2 only for rethrow");
287     ret = new TailJumpNode(if_null,
288                                i_o(),
289                                exit_memory,
290                                frameptr(),
291                                target, map()->in(TypeFunc::Parms));
292     break;
293   default:
294     ShouldNotReachHere();
295   }
296   root()->add_req(_gvn.transform(ret));
297 }