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src/hotspot/cpu/aarch64/vtableStubs_aarch64.cpp
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rev 51381 : [mq]: 8207343.patch
@@ -42,28 +42,34 @@
// initialize its code
#define __ masm->
#ifndef PRODUCT
-extern "C" void bad_compiled_vtable_index(JavaThread* thread,
- oop receiver,
- int index);
+extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
#endif
VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
- const int aarch64_code_length = VtableStub::pd_code_size_limit(true);
- VtableStub* s = new(aarch64_code_length) VtableStub(true, vtable_index);
+ // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
+ const int stub_code_length = VtableStub::code_size_limit(true);
+ VtableStub* s = new(stub_code_length) VtableStub(true, vtable_index);
// Can be NULL if there is no free space in the code cache.
if (s == NULL) {
return NULL;
}
+ // Count unused bytes in instruction sequences of variable size.
+ // We add them to the computed buffer size in order to avoid
+ // overflow in subsequently generated stubs.
+ address start_pc;
+ int slop_bytes = 0;
+ int slop_delta = 0;
+
ResourceMark rm;
- CodeBuffer cb(s->entry_point(), aarch64_code_length);
+ CodeBuffer cb(s->entry_point(), stub_code_length);
MacroAssembler* masm = new MacroAssembler(&cb);
-#ifndef PRODUCT
+#if (!defined(PRODUCT) && defined(COMPILER2))
if (CountCompiledCalls) {
__ lea(r16, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
__ incrementw(Address(r16));
}
#endif
@@ -82,71 +88,87 @@
__ ldrw(rscratch1, Address(r16, Klass::vtable_length_offset()));
__ cmpw(rscratch1, vtable_index * vtableEntry::size());
__ br(Assembler::GT, L);
__ enter();
__ mov(r2, vtable_index);
- __ call_VM(noreg,
- CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, r2);
+
+ // TODO: find upper bound for call_VM length.
+ start_pc = __ pc();
+ __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, r2);
+ slop_delta = 470 - (__ pc() - start_pc); // call_VM varies in length, depending on data
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
+
__ leave();
__ bind(L);
}
#endif // PRODUCT
+ start_pc = __ pc();
__ lookup_virtual_method(r16, vtable_index, rmethod);
+ slop_delta = 8 - (int)(__ pc() - start_pc);
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
+#ifndef PRODUCT
if (DebugVtables) {
Label L;
__ cbz(rmethod, L);
__ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
__ cbnz(rscratch1, L);
__ stop("Vtable entry is NULL");
__ bind(L);
}
+#endif // PRODUCT
+
// r0: receiver klass
// rmethod: Method*
// r2: receiver
address ame_addr = __ pc();
__ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
__ br(rscratch1);
- __ flush();
+ masm->flush();
+ bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);
- if (PrintMiscellaneous && (WizardMode || Verbose)) {
- tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d",
- vtable_index, p2i(s->entry_point()),
- (int)(s->code_end() - s->entry_point()),
- (int)(s->code_end() - __ pc()));
- }
- guarantee(__ pc() <= s->code_end(), "overflowed buffer");
-
- s->set_exception_points(npe_addr, ame_addr);
return s;
}
VtableStub* VtableStubs::create_itable_stub(int itable_index) {
- // Note well: pd_code_size_limit is the absolute minimum we can get
- // away with. If you add code here, bump the code stub size
- // returned by pd_code_size_limit!
- const int code_length = VtableStub::pd_code_size_limit(false);
- VtableStub* s = new(code_length) VtableStub(false, itable_index);
+ // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
+ const int stub_code_length = VtableStub::code_size_limit(false);
+ VtableStub* s = new(stub_code_length) VtableStub(false, itable_index);
+ // Can be NULL if there is no free space in the code cache.
+ if (s == NULL) {
+ return NULL;
+ }
+ // Count unused bytes in instruction sequences of variable size.
+ // We add them to the computed buffer size in order to avoid
+ // overflow in subsequently generated stubs.
+ address start_pc;
+ int slop_bytes = 0;
+ int slop_delta = 0;
+
ResourceMark rm;
- CodeBuffer cb(s->entry_point(), code_length);
+ CodeBuffer cb(s->entry_point(), stub_code_length);
MacroAssembler* masm = new MacroAssembler(&cb);
-#ifndef PRODUCT
+#if (!defined(PRODUCT) && defined(COMPILER2))
if (CountCompiledCalls) {
__ lea(r10, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
__ incrementw(Address(r10));
}
#endif
+ // get receiver (need to skip return address on top of stack)
+ assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
+
// Entry arguments:
// rscratch2: CompiledICHolder
// j_rarg0: Receiver
-
// Most registers are in use; we'll use r16, rmethod, r10, r11
const Register recv_klass_reg = r10;
const Register holder_klass_reg = r16; // declaring interface klass (DECC)
const Register resolved_klass_reg = rmethod; // resolved interface klass (REFC)
const Register temp_reg = r11;
@@ -155,12 +177,12 @@
Label L_no_such_interface;
__ ldr(resolved_klass_reg, Address(icholder_reg, CompiledICHolder::holder_klass_offset()));
__ ldr(holder_klass_reg, Address(icholder_reg, CompiledICHolder::holder_metadata_offset()));
- // get receiver (need to skip return address on top of stack)
- assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
+ start_pc = __ pc();
+
// get receiver klass (also an implicit null-check)
address npe_addr = __ pc();
__ load_klass(recv_klass_reg, j_rarg0);
// Receiver subtype check against REFC.
@@ -170,20 +192,29 @@
// outputs: scan temp. reg1, scan temp. reg2
recv_klass_reg, temp_reg,
L_no_such_interface,
/*return_method=*/false);
+ const ptrdiff_t typecheckSize = __ pc() - start_pc;
+ start_pc = __ pc();
+
// Get selected method from declaring class and itable index
__ load_klass(recv_klass_reg, j_rarg0); // restore recv_klass_reg
__ lookup_interface_method(// inputs: rec. class, interface, itable index
recv_klass_reg, holder_klass_reg, itable_index,
// outputs: method, scan temp. reg
rmethod, temp_reg,
L_no_such_interface);
- // method (rmethod): Method*
- // j_rarg0: receiver
+ const ptrdiff_t lookupSize = __ pc() - start_pc;
+
+ // Reduce "estimate" such that "padding" does not drop below 8.
+ const ptrdiff_t estimate = 152;
+ const ptrdiff_t codesize = typecheckSize + lookupSize;
+ slop_delta = (int)(estimate - codesize);
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "itable #%d: Code size estimate (%d) for lookup_interface_method too small, required: %d", itable_index, (int)estimate, (int)codesize);
#ifdef ASSERT
if (DebugVtables) {
Label L2;
__ cbz(rmethod, L2);
@@ -204,94 +235,19 @@
// Handle IncompatibleClassChangeError in itable stubs.
// More detailed error message.
// We force resolving of the call site by jumping to the "handle
// wrong method" stub, and so let the interpreter runtime do all the
// dirty work.
+ assert(SharedRuntime::get_handle_wrong_method_stub() != NULL, "check initialization order");
__ far_jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));
- __ flush();
-
- if (PrintMiscellaneous && (WizardMode || Verbose)) {
- tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d",
- itable_index, p2i(s->entry_point()),
- (int)(s->code_end() - s->entry_point()),
- (int)(s->code_end() - __ pc()));
- }
- guarantee(__ pc() <= s->code_end(), "overflowed buffer");
+ masm->flush();
+ bookkeeping(masm, tty, s, npe_addr, ame_addr, false, itable_index, slop_bytes, 0);
- s->set_exception_points(npe_addr, ame_addr);
return s;
}
-
-int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
- int size = DebugVtables ? 216 : 0;
- if (CountCompiledCalls)
- size += 6 * 4;
- // FIXME: vtable stubs only need 36 bytes
- if (is_vtable_stub)
- size += 52;
- else
- size += 176;
- return size;
-
- // In order to tune these parameters, run the JVM with VM options
- // +PrintMiscellaneous and +WizardMode to see information about
- // actual itable stubs. Run it with -Xmx31G -XX:+UseCompressedOops.
- //
- // If Universe::narrow_klass_base is nonzero, decoding a compressed
- // class can take zeveral instructions.
- //
- // The JVM98 app. _202_jess has a megamorphic interface call.
- // The itable code looks like this:
-
- // ldr xmethod, [xscratch2,#CompiledICHolder::holder_klass_offset]
- // ldr x0, [xscratch2]
- // ldr w10, [x1,#oopDesc::klass_offset_in_bytes]
- // mov xheapbase, #0x3c000000 // #narrow_klass_base
- // movk xheapbase, #0x3f7, lsl #32
- // add x10, xheapbase, x10
- // mov xheapbase, #0xe7ff0000 // #heapbase
- // movk xheapbase, #0x3f7, lsl #32
- // ldr w11, [x10,#vtable_length_offset]
- // add x11, x10, x11, uxtx #3
- // add x11, x11, #itableMethodEntry::method_offset_in_bytes
- // ldr x10, [x11]
- // cmp xmethod, x10
- // b.eq found_method
- // search:
- // cbz x10, no_such_interface
- // add x11, x11, #0x10
- // ldr x10, [x11]
- // cmp xmethod, x10
- // b.ne search
- // found_method:
- // ldr w10, [x1,#oopDesc::klass_offset_in_bytes]
- // mov xheapbase, #0x3c000000 // #narrow_klass_base
- // movk xheapbase, #0x3f7, lsl #32
- // add x10, xheapbase, x10
- // mov xheapbase, #0xe7ff0000 // #heapbase
- // movk xheapbase, #0x3f7, lsl #32
- // ldr w11, [x10,#vtable_length_offset]
- // add x11, x10, x11, uxtx #3
- // add x11, x11, #itableMethodEntry::method_offset_in_bytes
- // add x10, x10, #itentry_off
- // ldr xmethod, [x11]
- // cmp x0, xmethod
- // b.eq found_method2
- // search2:
- // cbz xmethod, 0x000003ffa872e6cc
- // add x11, x11, #0x10
- // ldr xmethod, [x11]
- // cmp x0, xmethod
- // b.ne search2
- // found_method2:
- // ldr w11, [x11,#itableOffsetEntry::offset_offset_in_bytes]
- // ldr xmethod, [x10,w11,uxtw]
- // ldr xscratch1, [xmethod,#Method::from_compiled_offset]
- // br xscratch1
- // no_such_interface:
- // b throw_ICCE_entry
-
+int VtableStub::pd_code_alignment() {
+ // aarch64 cache line size is not an architected constant. We just align on 4 bytes (instruction size).
+ const unsigned int icache_line_size = 4;
+ return icache_line_size;
}
-
-int VtableStub::pd_code_alignment() { return 4; }
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