Tue, 15 May 2012 10:10:23 +0200
7133857: exp() and pow() should use the x87 ISA on x86
Summary: use x87 instructions to implement exp() and pow() in interpreter/c1/c2.
Reviewed-by: kvn, never, twisti
1 /*
2 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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23 */
25 #include "precompiled.hpp"
26 #include "interpreter/bytecodes.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "interpreter/rewriter.hpp"
29 #include "memory/gcLocker.hpp"
30 #include "memory/oopFactory.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/generateOopMap.hpp"
33 #include "oops/objArrayOop.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "prims/methodComparator.hpp"
37 // Computes a CPC map (new_index -> original_index) for constant pool entries
38 // that are referred to by the interpreter at runtime via the constant pool cache.
39 // Also computes a CP map (original_index -> new_index).
40 // Marks entries in CP which require additional processing.
41 void Rewriter::compute_index_maps() {
42 const int length = _pool->length();
43 init_cp_map(length);
44 jint tag_mask = 0;
45 for (int i = 0; i < length; i++) {
46 int tag = _pool->tag_at(i).value();
47 tag_mask |= (1 << tag);
48 switch (tag) {
49 case JVM_CONSTANT_InterfaceMethodref:
50 case JVM_CONSTANT_Fieldref : // fall through
51 case JVM_CONSTANT_Methodref : // fall through
52 case JVM_CONSTANT_MethodHandle : // fall through
53 case JVM_CONSTANT_MethodType : // fall through
54 case JVM_CONSTANT_InvokeDynamic : // fall through
55 add_cp_cache_entry(i);
56 break;
57 }
58 }
60 guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1),
61 "all cp cache indexes fit in a u2");
63 _have_invoke_dynamic = ((tag_mask & (1 << JVM_CONSTANT_InvokeDynamic)) != 0);
64 }
66 // Unrewrite the bytecodes if an error occurs.
67 void Rewriter::restore_bytecodes() {
68 int len = _methods->length();
70 for (int i = len-1; i >= 0; i--) {
71 methodOop method = (methodOop)_methods->obj_at(i);
72 scan_method(method, true);
73 }
74 }
76 // Creates a constant pool cache given a CPC map
77 void Rewriter::make_constant_pool_cache(TRAPS) {
78 const int length = _cp_cache_map.length();
79 constantPoolCacheOop cache =
80 oopFactory::new_constantPoolCache(length, CHECK);
81 No_Safepoint_Verifier nsv;
82 cache->initialize(_cp_cache_map);
84 // Don't bother with the next pass if there is no JVM_CONSTANT_InvokeDynamic.
85 if (_have_invoke_dynamic) {
86 for (int i = 0; i < length; i++) {
87 int pool_index = cp_cache_entry_pool_index(i);
88 if (pool_index >= 0 &&
89 _pool->tag_at(pool_index).is_invoke_dynamic()) {
90 int bsm_index = _pool->invoke_dynamic_bootstrap_method_ref_index_at(pool_index);
91 assert(_pool->tag_at(bsm_index).is_method_handle(), "must be a MH constant");
92 // There is a CP cache entry holding the BSM for these calls.
93 int bsm_cache_index = cp_entry_to_cp_cache(bsm_index);
94 cache->entry_at(i)->initialize_bootstrap_method_index_in_cache(bsm_cache_index);
95 }
96 }
97 }
99 _pool->set_cache(cache);
100 cache->set_constant_pool(_pool());
101 }
105 // The new finalization semantics says that registration of
106 // finalizable objects must be performed on successful return from the
107 // Object.<init> constructor. We could implement this trivially if
108 // <init> were never rewritten but since JVMTI allows this to occur, a
109 // more complicated solution is required. A special return bytecode
110 // is used only by Object.<init> to signal the finalization
111 // registration point. Additionally local 0 must be preserved so it's
112 // available to pass to the registration function. For simplicty we
113 // require that local 0 is never overwritten so it's available as an
114 // argument for registration.
116 void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) {
117 RawBytecodeStream bcs(method);
118 while (!bcs.is_last_bytecode()) {
119 Bytecodes::Code opcode = bcs.raw_next();
120 switch (opcode) {
121 case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
123 case Bytecodes::_istore:
124 case Bytecodes::_lstore:
125 case Bytecodes::_fstore:
126 case Bytecodes::_dstore:
127 case Bytecodes::_astore:
128 if (bcs.get_index() != 0) continue;
130 // fall through
131 case Bytecodes::_istore_0:
132 case Bytecodes::_lstore_0:
133 case Bytecodes::_fstore_0:
134 case Bytecodes::_dstore_0:
135 case Bytecodes::_astore_0:
136 THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
137 "can't overwrite local 0 in Object.<init>");
138 break;
139 }
140 }
141 }
144 // Rewrite a classfile-order CP index into a native-order CPC index.
145 void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) {
146 address p = bcp + offset;
147 if (!reverse) {
148 int cp_index = Bytes::get_Java_u2(p);
149 int cache_index = cp_entry_to_cp_cache(cp_index);
150 Bytes::put_native_u2(p, cache_index);
151 } else {
152 int cache_index = Bytes::get_native_u2(p);
153 int pool_index = cp_cache_entry_pool_index(cache_index);
154 Bytes::put_Java_u2(p, pool_index);
155 }
156 }
159 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
160 address p = bcp + offset;
161 assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
162 if (!reverse) {
163 int cp_index = Bytes::get_Java_u2(p);
164 int cpc = maybe_add_cp_cache_entry(cp_index); // add lazily
165 int cpc2 = add_secondary_cp_cache_entry(cpc);
167 // Replace the trailing four bytes with a CPC index for the dynamic
168 // call site. Unlike other CPC entries, there is one per bytecode,
169 // not just one per distinct CP entry. In other words, the
170 // CPC-to-CP relation is many-to-one for invokedynamic entries.
171 // This means we must use a larger index size than u2 to address
172 // all these entries. That is the main reason invokedynamic
173 // must have a five-byte instruction format. (Of course, other JVM
174 // implementations can use the bytes for other purposes.)
175 Bytes::put_native_u4(p, constantPoolCacheOopDesc::encode_secondary_index(cpc2));
176 // Note: We use native_u4 format exclusively for 4-byte indexes.
177 } else {
178 int cache_index = constantPoolCacheOopDesc::decode_secondary_index(
179 Bytes::get_native_u4(p));
180 int secondary_index = cp_cache_secondary_entry_main_index(cache_index);
181 int pool_index = cp_cache_entry_pool_index(secondary_index);
182 assert(_pool->tag_at(pool_index).is_invoke_dynamic(), "wrong index");
183 // zero out 4 bytes
184 Bytes::put_Java_u4(p, 0);
185 Bytes::put_Java_u2(p, pool_index);
186 }
187 }
190 // Rewrite some ldc bytecodes to _fast_aldc
191 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide,
192 bool reverse) {
193 if (!reverse) {
194 assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode");
195 address p = bcp + offset;
196 int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p);
197 constantTag tag = _pool->tag_at(cp_index).value();
198 if (tag.is_method_handle() || tag.is_method_type()) {
199 int cache_index = cp_entry_to_cp_cache(cp_index);
200 if (is_wide) {
201 (*bcp) = Bytecodes::_fast_aldc_w;
202 assert(cache_index == (u2)cache_index, "index overflow");
203 Bytes::put_native_u2(p, cache_index);
204 } else {
205 (*bcp) = Bytecodes::_fast_aldc;
206 assert(cache_index == (u1)cache_index, "index overflow");
207 (*p) = (u1)cache_index;
208 }
209 }
210 } else {
211 Bytecodes::Code rewritten_bc =
212 (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
213 if ((*bcp) == rewritten_bc) {
214 address p = bcp + offset;
215 int cache_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
216 int pool_index = cp_cache_entry_pool_index(cache_index);
217 if (is_wide) {
218 (*bcp) = Bytecodes::_ldc_w;
219 assert(pool_index == (u2)pool_index, "index overflow");
220 Bytes::put_Java_u2(p, pool_index);
221 } else {
222 (*bcp) = Bytecodes::_ldc;
223 assert(pool_index == (u1)pool_index, "index overflow");
224 (*p) = (u1)pool_index;
225 }
226 }
227 }
228 }
231 // Rewrites a method given the index_map information
232 void Rewriter::scan_method(methodOop method, bool reverse) {
234 int nof_jsrs = 0;
235 bool has_monitor_bytecodes = false;
237 {
238 // We cannot tolerate a GC in this block, because we've
239 // cached the bytecodes in 'code_base'. If the methodOop
240 // moves, the bytecodes will also move.
241 No_Safepoint_Verifier nsv;
242 Bytecodes::Code c;
244 // Bytecodes and their length
245 const address code_base = method->code_base();
246 const int code_length = method->code_size();
248 int bc_length;
249 for (int bci = 0; bci < code_length; bci += bc_length) {
250 address bcp = code_base + bci;
251 int prefix_length = 0;
252 c = (Bytecodes::Code)(*bcp);
254 // Since we have the code, see if we can get the length
255 // directly. Some more complicated bytecodes will report
256 // a length of zero, meaning we need to make another method
257 // call to calculate the length.
258 bc_length = Bytecodes::length_for(c);
259 if (bc_length == 0) {
260 bc_length = Bytecodes::length_at(method, bcp);
262 // length_at will put us at the bytecode after the one modified
263 // by 'wide'. We don't currently examine any of the bytecodes
264 // modified by wide, but in case we do in the future...
265 if (c == Bytecodes::_wide) {
266 prefix_length = 1;
267 c = (Bytecodes::Code)bcp[1];
268 }
269 }
271 assert(bc_length != 0, "impossible bytecode length");
273 switch (c) {
274 case Bytecodes::_lookupswitch : {
275 #ifndef CC_INTERP
276 Bytecode_lookupswitch bc(method, bcp);
277 (*bcp) = (
278 bc.number_of_pairs() < BinarySwitchThreshold
279 ? Bytecodes::_fast_linearswitch
280 : Bytecodes::_fast_binaryswitch
281 );
282 #endif
283 break;
284 }
285 case Bytecodes::_fast_linearswitch:
286 case Bytecodes::_fast_binaryswitch: {
287 #ifndef CC_INTERP
288 (*bcp) = Bytecodes::_lookupswitch;
289 #endif
290 break;
291 }
292 case Bytecodes::_getstatic : // fall through
293 case Bytecodes::_putstatic : // fall through
294 case Bytecodes::_getfield : // fall through
295 case Bytecodes::_putfield : // fall through
296 case Bytecodes::_invokevirtual : // fall through
297 case Bytecodes::_invokespecial : // fall through
298 case Bytecodes::_invokestatic :
299 case Bytecodes::_invokeinterface:
300 rewrite_member_reference(bcp, prefix_length+1, reverse);
301 break;
302 case Bytecodes::_invokedynamic:
303 rewrite_invokedynamic(bcp, prefix_length+1, reverse);
304 break;
305 case Bytecodes::_ldc:
306 case Bytecodes::_fast_aldc:
307 maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
308 break;
309 case Bytecodes::_ldc_w:
310 case Bytecodes::_fast_aldc_w:
311 maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
312 break;
313 case Bytecodes::_jsr : // fall through
314 case Bytecodes::_jsr_w : nof_jsrs++; break;
315 case Bytecodes::_monitorenter : // fall through
316 case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
317 }
318 }
319 }
321 // Update access flags
322 if (has_monitor_bytecodes) {
323 method->set_has_monitor_bytecodes();
324 }
326 // The present of a jsr bytecode implies that the method might potentially
327 // have to be rewritten, so we run the oopMapGenerator on the method
328 if (nof_jsrs > 0) {
329 method->set_has_jsrs();
330 // Second pass will revisit this method.
331 assert(method->has_jsrs(), "didn't we just set this?");
332 }
333 }
335 // After constant pool is created, revisit methods containing jsrs.
336 methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) {
337 ResourceMark rm(THREAD);
338 ResolveOopMapConflicts romc(method);
339 methodHandle original_method = method;
340 method = romc.do_potential_rewrite(CHECK_(methodHandle()));
341 if (method() != original_method()) {
342 // Insert invalid bytecode into original methodOop and set
343 // interpreter entrypoint, so that a executing this method
344 // will manifest itself in an easy recognizable form.
345 address bcp = original_method->bcp_from(0);
346 *bcp = (u1)Bytecodes::_shouldnotreachhere;
347 int kind = Interpreter::method_kind(original_method);
348 original_method->set_interpreter_kind(kind);
349 }
351 // Update monitor matching info.
352 if (romc.monitor_safe()) {
353 method->set_guaranteed_monitor_matching();
354 }
356 return method;
357 }
359 void Rewriter::rewrite(instanceKlassHandle klass, TRAPS) {
360 ResourceMark rm(THREAD);
361 Rewriter rw(klass, klass->constants(), klass->methods(), CHECK);
362 // (That's all, folks.)
363 }
366 void Rewriter::rewrite(instanceKlassHandle klass, constantPoolHandle cpool, objArrayHandle methods, TRAPS) {
367 ResourceMark rm(THREAD);
368 Rewriter rw(klass, cpool, methods, CHECK);
369 // (That's all, folks.)
370 }
373 Rewriter::Rewriter(instanceKlassHandle klass, constantPoolHandle cpool, objArrayHandle methods, TRAPS)
374 : _klass(klass),
375 _pool(cpool),
376 _methods(methods)
377 {
378 assert(_pool->cache() == NULL, "constant pool cache must not be set yet");
380 // determine index maps for methodOop rewriting
381 compute_index_maps();
383 if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
384 bool did_rewrite = false;
385 int i = _methods->length();
386 while (i-- > 0) {
387 methodOop method = (methodOop)_methods->obj_at(i);
388 if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
389 // rewrite the return bytecodes of Object.<init> to register the
390 // object for finalization if needed.
391 methodHandle m(THREAD, method);
392 rewrite_Object_init(m, CHECK);
393 did_rewrite = true;
394 break;
395 }
396 }
397 assert(did_rewrite, "must find Object::<init> to rewrite it");
398 }
400 // rewrite methods, in two passes
401 int len = _methods->length();
403 for (int i = len-1; i >= 0; i--) {
404 methodOop method = (methodOop)_methods->obj_at(i);
405 scan_method(method);
406 }
408 // allocate constant pool cache, now that we've seen all the bytecodes
409 make_constant_pool_cache(THREAD);
411 // Restore bytecodes to their unrewritten state if there are exceptions
412 // rewriting bytecodes or allocating the cpCache
413 if (HAS_PENDING_EXCEPTION) {
414 restore_bytecodes();
415 return;
416 }
417 }
419 // Relocate jsr/rets in a method. This can't be done with the rewriter
420 // stage because it can throw other exceptions, leaving the bytecodes
421 // pointing at constant pool cache entries.
422 // Link and check jvmti dependencies while we're iterating over the methods.
423 // JSR292 code calls with a different set of methods, so two entry points.
424 void Rewriter::relocate_and_link(instanceKlassHandle this_oop, TRAPS) {
425 objArrayHandle methods(THREAD, this_oop->methods());
426 relocate_and_link(this_oop, methods, THREAD);
427 }
429 void Rewriter::relocate_and_link(instanceKlassHandle this_oop,
430 objArrayHandle methods, TRAPS) {
431 int len = methods->length();
432 for (int i = len-1; i >= 0; i--) {
433 methodHandle m(THREAD, (methodOop)methods->obj_at(i));
435 if (m->has_jsrs()) {
436 m = rewrite_jsrs(m, CHECK);
437 // Method might have gotten rewritten.
438 methods->obj_at_put(i, m());
439 }
441 // Set up method entry points for compiler and interpreter .
442 m->link_method(m, CHECK);
444 // This is for JVMTI and unrelated to relocator but the last thing we do
445 #ifdef ASSERT
446 if (StressMethodComparator) {
447 static int nmc = 0;
448 for (int j = i; j >= 0 && j >= i-4; j--) {
449 if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc);
450 bool z = MethodComparator::methods_EMCP(m(),
451 (methodOop)methods->obj_at(j));
452 if (j == i && !z) {
453 tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
454 assert(z, "method must compare equal to itself");
455 }
456 }
457 }
458 #endif //ASSERT
459 }
460 }