1 /*
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4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13  * version 2 for more details (a copy is included in the LICENSE file that
14  * accompanied this code).
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25 
26 #include "precompiled.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "code/vtableStubs.hpp"
29 #include "interp_masm_s390.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/compiledICHolder.hpp"
32 #include "oops/instanceKlass.hpp"
33 #include "oops/klassVtable.hpp"
34 #include "runtime/sharedRuntime.hpp"
35 #include "vmreg_s390.inline.hpp"
36 #ifdef COMPILER2
37 #include "opto/runtime.hpp"
38 #endif
39 
40 #define __ masm->
41 
42 #ifndef PRODUCT
43 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
44 #endif
45 
46 // Used by compiler only; may use only caller saved, non-argument registers.
create_vtable_stub(int vtable_index)47 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
48   // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
49   const int stub_code_length = code_size_limit(true);
50   VtableStub* s = new(stub_code_length) VtableStub(true, vtable_index);
51   // Can be NULL if there is no free space in the code cache.
52   if (s == NULL) {
53     return NULL;
54   }
55 
56   // Count unused bytes in instruction sequences of variable size.
57   // We add them to the computed buffer size in order to avoid
58   // overflow in subsequently generated stubs.
59   address   start_pc;
60   int       slop_bytes = 0;
61   int       slop_delta = 0;
62 
63   ResourceMark    rm;
64   CodeBuffer      cb(s->entry_point(), stub_code_length);
65   MacroAssembler* masm = new MacroAssembler(&cb);
66 
67 #if (!defined(PRODUCT) && defined(COMPILER2))
68   if (CountCompiledCalls) {
69     //               worst case             actual size
70     slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);
71     slop_bytes += slop_delta;
72     assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
73     // Use generic emitter for direct memory increment.
74     // Abuse Z_method as scratch register for generic emitter.
75     // It is loaded further down anyway before it is first used.
76     // No dynamic code size variance here, increment is 1, always.
77     __ add2mem_64(Address(Z_R1_scratch), 1, Z_method);
78   }
79 #endif
80 
81   assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");
82 
83   const Register rcvr_klass   = Z_R1_scratch;
84   address        npe_addr     = __ pc(); // npe == NULL ptr exception
85   // check if we must do an explicit check (implicit checks disabled, offset too large).
86   __ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());
87   // Get receiver klass.
88   __ load_klass(rcvr_klass, Z_ARG1);
89 
90 #ifndef PRODUCT
91   if (DebugVtables) {
92     NearLabel L;
93     // Check offset vs vtable length.
94     const Register vtable_idx = Z_R0_scratch;
95 
96     //               worst case             actual size
97     slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(vtable_idx, vtable_index*vtableEntry::size(), true);
98     slop_bytes += slop_delta;
99     assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
100 
101     assert(Displacement::is_shortDisp(in_bytes(Klass::vtable_length_offset())), "disp to large");
102     __ z_cl(vtable_idx, in_bytes(Klass::vtable_length_offset()), rcvr_klass);
103     __ z_brl(L);
104     __ z_lghi(Z_ARG3, vtable_index);  // Debug code, don't optimize.
105     __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), Z_ARG1, Z_ARG3, false);
106     // Count unused bytes (assume worst case here).
107     slop_bytes += 12;
108     __ bind(L);
109   }
110 #endif
111 
112   int entry_offset = in_bytes(Klass::vtable_start_offset()) +
113                      vtable_index * vtableEntry::size_in_bytes();
114   int v_off        = entry_offset + vtableEntry::method_offset_in_bytes();
115 
116   // Set method (in case of interpreted method), and destination address.
117   // Duplicate safety code from enc_class Java_Dynamic_Call_dynTOC.
118   if (Displacement::is_validDisp(v_off)) {
119     __ z_lg(Z_method/*method oop*/, v_off, rcvr_klass/*class oop*/);
120     // Account for the load_const in the else path.
121     slop_delta  = __ load_const_size();
122   } else {
123     // Worse case, offset does not fit in displacement field.
124     //               worst case             actual size
125     slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_method, v_off, true);
126     __ z_lg(Z_method/*method oop*/, 0, Z_method/*method offset*/, rcvr_klass/*class oop*/);
127   }
128   slop_bytes += slop_delta;
129 
130 #ifndef PRODUCT
131   if (DebugVtables) {
132     NearLabel L;
133     __ z_ltgr(Z_method, Z_method);
134     __ z_brne(L);
135     __ stop("Vtable entry is ZERO", 102);
136     __ bind(L);
137   }
138 #endif
139 
140   // Must do an explicit check if offset too large or implicit checks are disabled.
141   address ame_addr = __ pc();
142   __ null_check(Z_method, Z_R1_scratch, in_bytes(Method::from_compiled_offset()));
143   __ z_lg(Z_R1_scratch, in_bytes(Method::from_compiled_offset()), Z_method);
144   __ z_br(Z_R1_scratch);
145 
146   masm->flush();
147   bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);
148 
149   return s;
150 }
151 
create_itable_stub(int itable_index)152 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
153   // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
154   const int stub_code_length = code_size_limit(false);
155   VtableStub* s = new(stub_code_length) VtableStub(false, itable_index);
156   // Can be NULL if there is no free space in the code cache.
157   if (s == NULL) {
158     return NULL;
159   }
160 
161   // Count unused bytes in instruction sequences of variable size.
162   // We add them to the computed buffer size in order to avoid
163   // overflow in subsequently generated stubs.
164   address   start_pc;
165   int       slop_bytes = 0;
166   int       slop_delta = 0;
167 
168   ResourceMark    rm;
169   CodeBuffer      cb(s->entry_point(), stub_code_length);
170   MacroAssembler* masm = new MacroAssembler(&cb);
171 
172 #if (!defined(PRODUCT) && defined(COMPILER2))
173   if (CountCompiledCalls) {
174     //               worst case             actual size
175     slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);
176     slop_bytes += slop_delta;
177     assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
178     // Use generic emitter for direct memory increment.
179     // Abuse Z_method as scratch register for generic emitter.
180     // It is loaded further down anyway before it is first used.
181     // No dynamic code size variance here, increment is 1, always.
182     __ add2mem_64(Address(Z_R1_scratch), 1, Z_method);
183   }
184 #endif
185 
186   assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");
187 
188   // Entry arguments:
189   //  Z_method: Interface
190   //  Z_ARG1:   Receiver
191   NearLabel no_such_interface;
192   const Register rcvr_klass = Z_tmp_1,
193                  interface  = Z_tmp_2;
194 
195   // Get receiver klass.
196   // Must do an explicit check if offset too large or implicit checks are disabled.
197   address npe_addr = __ pc(); // npe == NULL ptr exception
198   __ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());
199   __ load_klass(rcvr_klass, Z_ARG1);
200 
201   // Receiver subtype check against REFC.
202   __ z_lg(interface, Address(Z_method, CompiledICHolder::holder_klass_offset()));
203   __ lookup_interface_method(rcvr_klass, interface, noreg,
204                              noreg, Z_R1, no_such_interface, /*return_method=*/ false);
205 
206   // Get Method* and entrypoint for compiler
207   __ z_lg(interface, Address(Z_method, CompiledICHolder::holder_metadata_offset()));
208   __ lookup_interface_method(rcvr_klass, interface, itable_index,
209                              Z_method, Z_R1, no_such_interface, /*return_method=*/ true);
210 
211 #ifndef PRODUCT
212   if (DebugVtables) {
213     NearLabel ok1;
214     __ z_ltgr(Z_method, Z_method);
215     __ z_brne(ok1);
216     __ stop("method is null", 103);
217     __ bind(ok1);
218   }
219 #endif
220 
221   address ame_addr = __ pc();
222   // Must do an explicit check if implicit checks are disabled.
223   if (!ImplicitNullChecks) {
224     __ compare64_and_branch(Z_method, (intptr_t) 0, Assembler::bcondEqual, no_such_interface);
225   }
226   __ z_lg(Z_R1_scratch, in_bytes(Method::from_compiled_offset()), Z_method);
227   __ z_br(Z_R1_scratch);
228 
229   // Handle IncompatibleClassChangeError in itable stubs.
230   __ bind(no_such_interface);
231   // more detailed IncompatibleClassChangeError
232   // we force re-resolving of the call site by jumping to
233   // the "handle wrong method" stub, thus letting the
234   // interpreter runtime do all the dirty work.
235   //               worst case          actual size
236   slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::get_handle_wrong_method_stub(), true);
237   slop_bytes += slop_delta;
238   assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
239   __ z_br(Z_R1_scratch);
240 
241   masm->flush();
242   bookkeeping(masm, tty, s, npe_addr, ame_addr, false, itable_index, slop_bytes, 0);
243 
244   return s;
245 }
246 
pd_code_alignment()247 int VtableStub::pd_code_alignment() {
248   // System z cache line size is 256 bytes, but octoword-alignment is quite ok.
249   const unsigned int icache_line_size = 32;
250   return icache_line_size;
251 }
252