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src/hotspot/cpu/s390/vtableStubs_s390.cpp
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rev 51490 : 8207343: Automate vtable/itable stub size calculation
Reviewed-by: kvn
@@ -1,8 +1,8 @@
/*
- * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2016, 2017 SAP SE. All rights reserved.
+ * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2018 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
@@ -35,138 +35,152 @@
#include "vmreg_s390.inline.hpp"
#ifdef COMPILER2
#include "opto/runtime.hpp"
#endif
-// Machine-dependent part of VtableStubs: create vtableStub of correct
-// size and initialize its code.
-
#define __ masm->
#ifndef PRODUCT
extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
#endif
// Used by compiler only; may use only caller saved, non-argument registers.
VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
-
- const int code_length = VtableStub::pd_code_size_limit(true);
- VtableStub *s = new(code_length) VtableStub(true, vtable_index);
- if (s == NULL) { // Indicates OOM In the code cache.
+ // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
+ const int stub_code_length = 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(), code_length);
- MacroAssembler *masm = new MacroAssembler(&cb);
- int padding_bytes = 0;
+ CodeBuffer cb(s->entry_point(), stub_code_length);
+ MacroAssembler* masm = new MacroAssembler(&cb);
#if (!defined(PRODUCT) && defined(COMPILER2))
if (CountCompiledCalls) {
- // Count unused bytes
// worst case actual size
- padding_bytes += __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);
-
+ slop_delta = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
// Use generic emitter for direct memory increment.
// Abuse Z_method as scratch register for generic emitter.
// It is loaded further down anyway before it is first used.
+ // No dynamic code size variance here, increment is 1, always.
__ add2mem_32(Address(Z_R1_scratch), 1, Z_method);
}
#endif
assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");
- // Get receiver klass.
- // Must do an explicit check if implicit checks are disabled.
+ const Register rcvr_klass = Z_R1_scratch;
address npe_addr = __ pc(); // npe == NULL ptr exception
+ // check if we must do an explicit check (implicit checks disabled, offset too large).
__ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());
- const Register rcvr_klass = Z_R1_scratch;
+ // Get receiver klass.
__ load_klass(rcvr_klass, Z_ARG1);
- // Set method (in case of interpreted method), and destination address.
- int entry_offset = in_bytes(Klass::vtable_start_offset()) +
- vtable_index * vtableEntry::size_in_bytes();
-
#ifndef PRODUCT
if (DebugVtables) {
- Label L;
+ NearLabel L;
// Check offset vs vtable length.
const Register vtable_idx = Z_R0_scratch;
- // Count unused bytes.
// worst case actual size
- padding_bytes += __ load_const_size() - __ load_const_optimized_rtn_len(vtable_idx, vtable_index*vtableEntry::size_in_bytes(), true);
+ slop_delta = __ load_const_size() - __ load_const_optimized_rtn_len(vtable_idx, vtable_index*vtableEntry::size(), true);
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
- assert(Immediate::is_uimm12(in_bytes(Klass::vtable_length_offset())), "disp to large");
+ assert(Displacement::is_shortDisp(in_bytes(Klass::vtable_length_offset())), "disp to large");
__ z_cl(vtable_idx, in_bytes(Klass::vtable_length_offset()), rcvr_klass);
__ z_brl(L);
__ z_lghi(Z_ARG3, vtable_index); // Debug code, don't optimize.
__ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), Z_ARG1, Z_ARG3, false);
// Count unused bytes (assume worst case here).
- padding_bytes += 12;
+ slop_bytes += 12;
__ bind(L);
}
#endif
+ int entry_offset = in_bytes(Klass::vtable_start_offset()) +
+ vtable_index * vtableEntry::size_in_bytes();
int v_off = entry_offset + vtableEntry::method_offset_in_bytes();
+ // Set method (in case of interpreted method), and destination address.
// Duplicate safety code from enc_class Java_Dynamic_Call_dynTOC.
if (Displacement::is_validDisp(v_off)) {
__ z_lg(Z_method/*method oop*/, v_off, rcvr_klass/*class oop*/);
// Account for the load_const in the else path.
- padding_bytes += __ load_const_size();
+ slop_delta = __ load_const_size();
} else {
// Worse case, offset does not fit in displacement field.
- __ load_const(Z_method, v_off); // Z_method temporarily holds the offset value.
+ // worst case actual size
+ slop_delta = __ load_const_size() - __ load_const_optimized_rtn_len(Z_method, v_off, true);
__ z_lg(Z_method/*method oop*/, 0, Z_method/*method offset*/, rcvr_klass/*class oop*/);
}
+ slop_bytes += slop_delta;
#ifndef PRODUCT
if (DebugVtables) {
- Label L;
+ NearLabel L;
__ z_ltgr(Z_method, Z_method);
__ z_brne(L);
- __ stop("Vtable entry is ZERO",102);
+ __ stop("Vtable entry is ZERO", 102);
__ bind(L);
}
#endif
- address ame_addr = __ pc(); // ame = abstract method error
-
- // Must do an explicit check if implicit checks are disabled.
+ // Must do an explicit check if offset too large or implicit checks are disabled.
+ address ame_addr = __ pc();
__ null_check(Z_method, Z_R1_scratch, in_bytes(Method::from_compiled_offset()));
__ z_lg(Z_R1_scratch, in_bytes(Method::from_compiled_offset()), Z_method);
__ z_br(Z_R1_scratch);
masm->flush();
-
- s->set_exception_points(npe_addr, ame_addr);
+ bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);
return s;
}
VtableStub* VtableStubs::create_itable_stub(int itable_index) {
- const int code_length = VtableStub::pd_code_size_limit(false);
- VtableStub *s = new(code_length) VtableStub(false, itable_index);
- if (s == NULL) { // Indicates OOM in the code cache.
+ // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
+ const int stub_code_length = 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);
- MacroAssembler *masm = new MacroAssembler(&cb);
- int padding_bytes = 0;
+ CodeBuffer cb(s->entry_point(), stub_code_length);
+ MacroAssembler* masm = new MacroAssembler(&cb);
#if (!defined(PRODUCT) && defined(COMPILER2))
if (CountCompiledCalls) {
- // Count unused bytes
// worst case actual size
- padding_bytes += __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);
-
+ slop_delta = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
// Use generic emitter for direct memory increment.
- // Use Z_tmp_1 as scratch register for generic emitter.
- __ add2mem_32((Z_R1_scratch), 1, Z_tmp_1);
+ // Abuse Z_method as scratch register for generic emitter.
+ // It is loaded further down anyway before it is first used.
+ // No dynamic code size variance here, increment is 1, always.
+ __ add2mem_32(Address(Z_R1_scratch), 1, Z_method);
}
#endif
assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");
@@ -176,11 +190,11 @@
NearLabel no_such_interface;
const Register rcvr_klass = Z_tmp_1,
interface = Z_tmp_2;
// Get receiver klass.
- // Must do an explicit check if implicit checks are disabled.
+ // Must do an explicit check if offset too large or implicit checks are disabled.
address npe_addr = __ pc(); // npe == NULL ptr exception
__ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());
__ load_klass(rcvr_klass, Z_ARG1);
// Receiver subtype check against REFC.
@@ -193,14 +207,14 @@
__ lookup_interface_method(rcvr_klass, interface, itable_index,
Z_method, Z_R1, no_such_interface, /*return_method=*/ true);
#ifndef PRODUCT
if (DebugVtables) {
- Label ok1;
+ NearLabel ok1;
__ z_ltgr(Z_method, Z_method);
__ z_brne(ok1);
- __ stop("method is null",103);
+ __ stop("method is null", 103);
__ bind(ok1);
}
#endif
address ame_addr = __ pc();
@@ -211,41 +225,26 @@
__ z_lg(Z_R1_scratch, in_bytes(Method::from_compiled_offset()), Z_method);
__ z_br(Z_R1_scratch);
// Handle IncompatibleClassChangeError in itable stubs.
__ bind(no_such_interface);
- // Count unused bytes
- // worst case actual size
- // We force resolving of the call site by jumping to
- // the "handle wrong method" stub, and so let the
+ // more detailed IncompatibleClassChangeError
+ // we force re-resolving of the call site by jumping to
+ // the "handle wrong method" stub, thus letting the
// interpreter runtime do all the dirty work.
- padding_bytes += __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::get_handle_wrong_method_stub(), true);
+ // worst case actual size
+ slop_delta = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::get_handle_wrong_method_stub(), true);
+ slop_bytes += slop_delta;
+ assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
__ z_br(Z_R1_scratch);
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;
}
-// 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.
-int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
- int size = DebugVtables ? 216 : 0;
- if (CountCompiledCalls) {
- size += 6 * 4;
- }
- size += is_vtable_stub ? 36 : 140;
- if (UseCompressedClassPointers) {
- size += MacroAssembler::instr_size_for_decode_klass_not_null();
- }
- if (!ImplicitNullChecks) {
- size += 36;
- }
- return size;
-}
-
int VtableStub::pd_code_alignment() {
+ // System z cache line size is 256 bytes, but octoword-alignment is quite ok.
const unsigned int icache_line_size = 32;
return icache_line_size;
}
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