1 /*
2 * Copyright (c) 1999, 2026, 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_sig();
51 const TypeTuple *jrange = C->tf()->range_sig();
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 = off_heap_plus_addr(thread,
92 in_bytes(JavaThread::frame_anchor_offset()) +
93 in_bytes(JavaFrameAnchor::last_Java_pc_offset()));
94
95 // Drop in the last_Java_sp. last_Java_fp is not touched.
96 // Always do this after the other "last_Java_frame" fields are set since
97 // as soon as last_Java_sp != nullptr the has_last_Java_frame is true and
98 // users will look at the other fields.
99 //
100 Node* adr_sp = off_heap_plus_addr(thread, in_bytes(JavaThread::last_Java_sp_offset()));
101 Node* last_sp = frameptr();
102 store_to_memory(control(), adr_sp, last_sp, T_ADDRESS, MemNode::unordered);
103
104 // Set _thread_in_native
105 // The order of stores into TLS is critical! Setting _thread_in_native MUST
106 // be last, because a GC is allowed at any time after setting it and the GC
107 // will require last_Java_pc and last_Java_sp.
108
109 //-----------------------------
110 // Compute signature for C call. Varies from the Java signature!
111
112 const Type **fields = TypeTuple::fields(2*parm_cnt+2);
113 uint cnt = TypeFunc::Parms;
114 // The C routines gets the base of thread-local storage passed in as an
115 // extra argument. Not all calls need it, but it is cheap to add here.
116 for (uint pcnt = cnt; pcnt < parm_cnt; pcnt++, cnt++) {
117 const Type *f = jdomain->field_at(pcnt);
118 if (CCallingConventionRequiresIntsAsLongs && f->isa_int()) {
119 fields[cnt++] = TypeLong::LONG;
120 fields[cnt] = Type::HALF; // Must add an additional half for a long.
121 } else {
122 fields[cnt] = f;
123 }
124 }
125 fields[cnt++] = TypeRawPtr::BOTTOM; // Thread-local storage
126 // Also pass in the caller's PC, if asked for.
127 if (return_pc) {
128 fields[cnt++] = TypeRawPtr::BOTTOM; // Return PC
129 }
130 const TypeTuple* domain = TypeTuple::make(cnt, fields);
131
132 // The C routine we are about to call cannot return an oop; it can block on
133 // exit and a GC will trash the oop while it sits in C-land. Instead, we
134 // return the oop through TLS for runtime calls.
135 // Also, C routines returning integer subword values leave the high
136 // order bits dirty; these must be cleaned up by explicit sign extension.
137 const Type* retval = (jrange->cnt() == TypeFunc::Parms) ? Type::TOP : jrange->field_at(TypeFunc::Parms);
138 // Make a private copy of jrange->fields();
139 const Type **rfields = TypeTuple::fields(jrange->cnt() - TypeFunc::Parms);
140 // Fixup oop returns
141 int retval_ptr = retval->isa_oop_ptr();
142 if (retval_ptr) {
143 assert( pass_tls, "Oop must be returned thru TLS" );
144 // Fancy-jumps return address; others return void
145 rfields[TypeFunc::Parms] = is_fancy_jump ? TypeRawPtr::BOTTOM : Type::TOP;
146
147 } else if (retval->isa_int()) { // Returning any integer subtype?
148 // "Fatten" byte, char & short return types to 'int' to show that
149 // the native C code can return values with junk high order bits.
150 // We'll sign-extend it below later.
151 rfields[TypeFunc::Parms] = TypeInt::INT; // It's "dirty" and needs sign-ext
152
153 } else if (jrange->cnt() >= TypeFunc::Parms+1) { // Else copy other types
154 rfields[TypeFunc::Parms] = jrange->field_at(TypeFunc::Parms);
155 if (jrange->cnt() == TypeFunc::Parms+2) {
156 rfields[TypeFunc::Parms+1] = jrange->field_at(TypeFunc::Parms+1);
157 }
158 }
159 const TypeTuple* range = TypeTuple::make(jrange->cnt(), rfields);
160
161 // Final C signature
162 const TypeFunc *c_sig = TypeFunc::make(domain, range);
163
164 //-----------------------------
165 // Make the call node.
166 CallRuntimeNode* call = new CallRuntimeNode(c_sig, C_function, name, TypePtr::BOTTOM, new (C) JVMState(0));
167 //-----------------------------
168
169 // Fix-up the debug info for the call.
170 call->jvms()->set_bci(0);
171 call->jvms()->set_offsets(cnt);
172
173 // Set fixed predefined input arguments.
174 cnt = 0;
175 for (i = 0; i < TypeFunc::Parms; i++) {
176 call->init_req(cnt++, map()->in(i));
177 }
178 // A little too aggressive on the parm copy; return address is not an input.
179 call->set_req(TypeFunc::ReturnAdr, top());
180 for (; i < parm_cnt; i++) { // Regular input arguments.
181 const Type *f = jdomain->field_at(i);
182 if (CCallingConventionRequiresIntsAsLongs && f->isa_int()) {
183 call->init_req(cnt++, _gvn.transform(new ConvI2LNode(map()->in(i))));
184 call->init_req(cnt++, top());
185 } else {
186 call->init_req(cnt++, map()->in(i));
187 }
188 }
189 call->init_req(cnt++, thread);
190 if (return_pc) { // Return PC, if asked for.
191 call->init_req(cnt++, returnadr());
192 }
193
194 _gvn.transform(call);
195
196 //-----------------------------
197 // Now set up the return results
198 set_control( _gvn.transform( new ProjNode(call,TypeFunc::Control)) );
199 set_i_o( _gvn.transform( new ProjNode(call,TypeFunc::I_O )) );
200 set_all_memory_call(call);
201 if (range->cnt() > TypeFunc::Parms) {
202 Node* retnode = _gvn.transform( new ProjNode(call,TypeFunc::Parms) );
203 // C-land is allowed to return sub-word values. Convert to integer type.
204 assert( retval != Type::TOP, "" );
205 if (retval == TypeInt::BOOL) {
206 retnode = _gvn.transform( new AndINode(retnode, intcon(0xFF)) );
207 } else if (retval == TypeInt::CHAR) {
208 retnode = _gvn.transform( new AndINode(retnode, intcon(0xFFFF)) );
209 } else if (retval == TypeInt::BYTE) {
210 retnode = _gvn.transform( new LShiftINode(retnode, intcon(24)) );
211 retnode = _gvn.transform( new RShiftINode(retnode, intcon(24)) );
212 } else if (retval == TypeInt::SHORT) {
213 retnode = _gvn.transform( new LShiftINode(retnode, intcon(16)) );
214 retnode = _gvn.transform( new RShiftINode(retnode, intcon(16)) );
215 }
216 map()->set_req( TypeFunc::Parms, retnode );
217 }
218
219 //-----------------------------
220
221 // Clear last_Java_sp
222 store_to_memory(control(), adr_sp, null(), T_ADDRESS, MemNode::unordered);
223 // Clear last_Java_pc
224 store_to_memory(control(), adr_last_Java_pc, null(), T_ADDRESS, MemNode::unordered);
225
226 // For is-fancy-jump, the C-return value is also the branch target
227 Node* target = map()->in(TypeFunc::Parms);
228 // Runtime call returning oop in TLS? Fetch it out
229 if( pass_tls ) {
230 Node* adr = off_heap_plus_addr(thread, in_bytes(JavaThread::vm_result_oop_offset()));
231 Node* vm_result = make_load(nullptr, adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered);
232 map()->set_req(TypeFunc::Parms, vm_result); // vm_result passed as result
233 // clear thread-local-storage(tls)
234 store_to_memory(control(), adr, null(), T_ADDRESS, MemNode::unordered);
235 }
236
237 //-----------------------------
238 // check exception
239 Node* adr = off_heap_plus_addr(thread, in_bytes(Thread::pending_exception_offset()));
240 Node* pending = make_load(nullptr, adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered);
241
242 Node* exit_memory = reset_memory();
243
244 Node* cmp = _gvn.transform( new CmpPNode(pending, null()) );
245 Node* bo = _gvn.transform( new BoolNode(cmp, BoolTest::ne) );
246 IfNode *iff = create_and_map_if(control(), bo, PROB_MIN, COUNT_UNKNOWN);
247
248 Node* if_null = _gvn.transform( new IfFalseNode(iff) );
249 Node* if_not_null = _gvn.transform( new IfTrueNode(iff) );
250
251 assert (StubRoutines::forward_exception_entry() != nullptr, "must be generated before");
252 Node *to_exc = new ForwardExceptionNode(if_not_null,
253 i_o(),
254 exit_memory,
255 frameptr(),
256 returnadr());
257 root()->add_req(_gvn.transform(to_exc)); // bind to root to keep live
258 C->verify_start(start);
259
260 //-----------------------------
261 // If this is a normal subroutine return, issue the return and be done.
262 Node *ret = nullptr;
263 switch( is_fancy_jump ) {
264 case 0: // Make a return instruction
265 // Return to caller, free any space for return address
266 ret = new ReturnNode(TypeFunc::Parms, if_null,
267 i_o(),
268 exit_memory,
269 frameptr(),
270 returnadr());
271 if (C->tf()->range_sig()->cnt() > TypeFunc::Parms)
272 ret->add_req( map()->in(TypeFunc::Parms) );
273 break;
274 case 1: // This is a fancy tail-call jump. Jump to computed address.
275 // Jump to new callee; leave old return address alone.
276 ret = new TailCallNode(if_null,
277 i_o(),
278 exit_memory,
279 frameptr(),
280 returnadr(),
281 target, map()->in(TypeFunc::Parms));
282 break;
283 case 2: // Pop return address & jump
284 // Throw away old return address; jump to new computed address
285 //assert(C_function == CAST_FROM_FN_PTR(address, OptoRuntime::rethrow_C), "fancy_jump==2 only for rethrow");
286 ret = new TailJumpNode(if_null,
287 i_o(),
288 exit_memory,
289 frameptr(),
290 target, map()->in(TypeFunc::Parms));
291 break;
292 default:
293 ShouldNotReachHere();
294 }
295 root()->add_req(_gvn.transform(ret));
296 }