JDK14/Java14源码在线阅读
/*
* Copyright (c) 2008, 2019, Oracle and/or its affiliates. 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.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "asm/assembler.hpp"
#include "assembler_arm.inline.hpp"
#include "gc/shared/barrierSet.hpp"
#include "gc/shared/barrierSetAssembler.hpp"
#include "interpreter/interpreter.hpp"
#include "memory/universe.hpp"
#include "nativeInst_arm.hpp"
#include "oops/instanceOop.hpp"
#include "oops/method.hpp"
#include "oops/objArrayKlass.hpp"
#include "oops/oop.inline.hpp"
#include "prims/methodHandles.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/stubCodeGenerator.hpp"
#include "runtime/stubRoutines.hpp"
#include "utilities/align.hpp"
#ifdef COMPILER2
#include "opto/runtime.hpp"
#endif
// Declaration and definition of StubGenerator (no .hpp file).
// For a more detailed description of the stub routine structure
// see the comment in stubRoutines.hpp
#define __ _masm->
#ifdef PRODUCT
#define BLOCK_COMMENT(str) /* nothing */
#else
#define BLOCK_COMMENT(str) __ block_comment(str)
#endif
#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
// -------------------------------------------------------------------------------------------------------------------------
// Stub Code definitions
// Platform dependent parameters for array copy stubs
// Note: we have noticed a huge change in behavior on a microbenchmark
// from platform to platform depending on the configuration.
// Instead of adding a series of command line options (which
// unfortunately have to be done in the shared file and cannot appear
// only in the ARM port), the tested result are hard-coded here in a set
// of options, selected by specifying 'ArmCopyPlatform'
// Currently, this 'platform' is hardcoded to a value that is a good
// enough trade-off. However, one can easily modify this file to test
// the hard-coded configurations or create new ones. If the gain is
// significant, we could decide to either add command line options or
// add code to automatically choose a configuration.
// see comments below for the various configurations created
#define DEFAULT_ARRAYCOPY_CONFIG 0
#define TEGRA2_ARRAYCOPY_CONFIG 1
#define IMX515_ARRAYCOPY_CONFIG 2
// Hard coded choices (XXX: could be changed to a command line option)
#define ArmCopyPlatform DEFAULT_ARRAYCOPY_CONFIG
#define ArmCopyCacheLineSize 32 // not worth optimizing to 64 according to measured gains
// configuration for each kind of loop
typedef struct {
int pld_distance; // prefetch distance (0 => no prefetch, <0: prefetch_before);
bool split_ldm; // if true, split each STM in STMs with fewer registers
bool split_stm; // if true, split each LTM in LTMs with fewer registers
} arraycopy_loop_config;
// configuration for all loops
typedef struct {
// const char *description;
arraycopy_loop_config forward_aligned;
arraycopy_loop_config backward_aligned;
arraycopy_loop_config forward_shifted;
arraycopy_loop_config backward_shifted;
} arraycopy_platform_config;
// configured platforms
static arraycopy_platform_config arraycopy_configurations[] = {
// configuration parameters for arraycopy loops
// Configurations were chosen based on manual analysis of benchmark
// results, minimizing overhead with respect to best results on the
// different test cases.
// Prefetch before is always favored since it avoids dirtying the
// cache uselessly for small copies. Code for prefetch after has
// been kept in case the difference is significant for some
// platforms but we might consider dropping it.
// distance, ldm, stm
{
// default: tradeoff tegra2/imx515/nv-tegra2,
// Notes on benchmarking:
// - not far from optimal configuration on nv-tegra2
// - within 5% of optimal configuration except for backward aligned on IMX
// - up to 40% from optimal configuration for backward shifted and backward align for tegra2
// but still on par with the operating system copy
{-256, true, true }, // forward aligned
{-256, true, true }, // backward aligned
{-256, false, false }, // forward shifted
{-256, true, true } // backward shifted
},
{
// configuration tuned on tegra2-4.
// Warning: should not be used on nv-tegra2 !
// Notes:
// - prefetch after gives 40% gain on backward copies on tegra2-4,
// resulting in better number than the operating system
// copy. However, this can lead to a 300% loss on nv-tegra and has
// more impact on the cache (fetches futher than what is
// copied). Use this configuration with care, in case it improves
// reference benchmarks.
{-256, true, true }, // forward aligned
{96, false, false }, // backward aligned
{-256, false, false }, // forward shifted
{96, false, false } // backward shifted
},
{
// configuration tuned on imx515
// Notes:
// - smaller prefetch distance is sufficient to get good result and might be more stable
// - refined backward aligned options within 5% of optimal configuration except for
// tests were the arrays fit in the cache
{-160, false, false }, // forward aligned
{-160, false, false }, // backward aligned
{-160, false, false }, // forward shifted
{-160, true, true } // backward shifted
}
};
class StubGenerator: public StubCodeGenerator {
#ifdef PRODUCT
#define inc_counter_np(a,b,c) ((void)0)
#else
#define inc_counter_np(counter, t1, t2) \
BLOCK_COMMENT("inc_counter " #counter); \
__ inc_counter(&counter, t1, t2);
#endif
private:
address generate_call_stub(address& return_address) {
StubCodeMark mark(this, "StubRoutines", "call_stub");
address start = __ pc();
assert(frame::entry_frame_call_wrapper_offset == 0, "adjust this code");
__ mov(Rtemp, SP);
__ push(RegisterSet(FP) | RegisterSet(LR));
#ifndef __SOFTFP__
__ fstmdbd(SP, FloatRegisterSet(D8, 8), writeback);
#endif
__ stmdb(SP, RegisterSet(R0, R2) | RegisterSet(R4, R6) | RegisterSet(R8, R10) | altFP_7_11, writeback);
__ mov(Rmethod, R3);
__ ldmia(Rtemp, RegisterSet(R1, R3) | Rthread); // stacked arguments
// XXX: TODO
// Would be better with respect to native tools if the following
// setting of FP was changed to conform to the native ABI, with FP
// pointing to the saved FP slot (and the corresponding modifications
// for entry_frame_call_wrapper_offset and frame::real_fp).
__ mov(FP, SP);
{
Label no_parameters, pass_parameters;
__ cmp(R3, 0);
__ b(no_parameters, eq);
__ bind(pass_parameters);
__ ldr(Rtemp, Address(R2, wordSize, post_indexed)); // Rtemp OK, unused and scratchable
__ subs(R3, R3, 1);
__ push(Rtemp);
__ b(pass_parameters, ne);
__ bind(no_parameters);
}
__ mov(Rsender_sp, SP);
__ blx(R1);
return_address = __ pc();
__ add(SP, FP, wordSize); // Skip link to JavaCallWrapper
__ pop(RegisterSet(R2, R3));
#ifndef __ABI_HARD__
__ cmp(R3, T_LONG);
__ cmp(R3, T_DOUBLE, ne);
__ str(R0, Address(R2));
__ str(R1, Address(R2, wordSize), eq);
#else
Label cont, l_float, l_double;
__ cmp(R3, T_DOUBLE);
__ b(l_double, eq);
__ cmp(R3, T_FLOAT);
__ b(l_float, eq);
__ cmp(R3, T_LONG);
__ str(R0, Address(R2));
__ str(R1, Address(R2, wordSize), eq);
__ b(cont);
__ bind(l_double);
__ fstd(D0, Address(R2));
__ b(cont);
__ bind(l_float);
__ fsts(S0, Address(R2));
__ bind(cont);
#endif
__ pop(RegisterSet(R4, R6) | RegisterSet(R8, R10) | altFP_7_11);
#ifndef __SOFTFP__
__ fldmiad(SP, FloatRegisterSet(D8, 8), writeback);
#endif
__ pop(RegisterSet(FP) | RegisterSet(PC));
return start;
}
// (in) Rexception_obj: exception oop
address generate_catch_exception() {
StubCodeMark mark(this, "StubRoutines", "catch_exception");
address start = __ pc();
__ str(Rexception_obj, Address(Rthread, Thread::pending_exception_offset()));
__ b(StubRoutines::_call_stub_return_address);
return start;
}
// (in) Rexception_pc: return address
address generate_forward_exception() {
StubCodeMark mark(this, "StubRoutines", "forward exception");
address start = __ pc();
__ mov(c_rarg0, Rthread);
__ mov(c_rarg1, Rexception_pc);
__ call_VM_leaf(CAST_FROM_FN_PTR(address,
SharedRuntime::exception_handler_for_return_address),
c_rarg0, c_rarg1);
__ ldr(Rexception_obj, Address(Rthread, Thread::pending_exception_offset()));
const Register Rzero = __ zero_register(Rtemp); // Rtemp OK (cleared by above call)
__ str(Rzero, Address(Rthread, Thread::pending_exception_offset()));
#ifdef ASSERT
// make sure exception is set
{ Label L;
__ cbnz(Rexception_obj, L);
__ stop("StubRoutines::forward exception: no pending exception (2)");
__ bind(L);
}
#endif
// Verify that there is really a valid exception in RAX.
__ verify_oop(Rexception_obj);
__ jump(R0); // handler is returned in R0 by runtime function
return start;
}
// Integer division shared routine
// Input:
// R0 - dividend
// R2 - divisor
// Output:
// R0 - remainder
// R1 - quotient
// Destroys:
// R2
// LR
address generate_idiv_irem() {
Label positive_arguments, negative_or_zero, call_slow_path;
Register dividend = R0;
Register divisor = R2;
Register remainder = R0;
Register quotient = R1;
Register tmp = LR;
assert(dividend == remainder, "must be");
address start = __ pc();
// Check for special cases: divisor <= 0 or dividend < 0
__ cmp(divisor, 0);
__ orrs(quotient, dividend, divisor, ne);
__ b(negative_or_zero, le);
__ bind(positive_arguments);
// Save return address on stack to free one extra register
__ push(LR);
// Approximate the mamximum order of the quotient
__ clz(tmp, dividend);
__ clz(quotient, divisor);
__ subs(tmp, quotient, tmp);
__ mov(quotient, 0);
// Jump to the appropriate place in the unrolled loop below
__ ldr(PC, Address(PC, tmp, lsl, 2), pl);
// If divisor is greater than dividend, return immediately
__ pop(PC);
// Offset table
Label offset_table[32];
int i;
for (i = 0; i <= 31; i++) {
__ emit_address(offset_table[i]);
}
// Unrolled loop of 32 division steps
for (i = 31; i >= 0; i--) {
__ bind(offset_table[i]);
__ cmp(remainder, AsmOperand(divisor, lsl, i));
__ sub(remainder, remainder, AsmOperand(divisor, lsl, i), hs);
__ add(quotient, quotient, 1 << i, hs);
}
__ pop(PC);
__ bind(negative_or_zero);
// Find the combination of argument signs and jump to corresponding handler
__ andr(quotient, dividend, 0x80000000, ne);
__ orr(quotient, quotient, AsmOperand(divisor, lsr, 31), ne);
__ add(PC, PC, AsmOperand(quotient, ror, 26), ne);
__ str(LR, Address(Rthread, JavaThread::saved_exception_pc_offset()));
// The leaf runtime function can destroy R0-R3 and R12 registers which are still alive
RegisterSet saved_registers = RegisterSet(R3) | RegisterSet(R12);
#if R9_IS_SCRATCHED
// Safer to save R9 here since callers may have been written
// assuming R9 survives. This is suboptimal but may not be worth
// revisiting for this slow case.
// save also R10 for alignment
saved_registers = saved_registers | RegisterSet(R9, R10);
#endif
{
// divisor == 0
FixedSizeCodeBlock zero_divisor(_masm, 8, true);
__ push(saved_registers);
__ mov(R0, Rthread);
__ mov(R1, LR);
__ mov(R2, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
__ b(call_slow_path);
}
{
// divisor > 0 && dividend < 0
FixedSizeCodeBlock positive_divisor_negative_dividend(_masm, 8, true);
__ push(LR);
__ rsb(dividend, dividend, 0);
__ bl(positive_arguments);
__ rsb(remainder, remainder, 0);
__ rsb(quotient, quotient, 0);
__ pop(PC);
}
{
// divisor < 0 && dividend > 0
FixedSizeCodeBlock negative_divisor_positive_dividend(_masm, 8, true);
__ push(LR);
__ rsb(divisor, divisor, 0);
__ bl(positive_arguments);
__ rsb(quotient, quotient, 0);
__ pop(PC);
}
{
// divisor < 0 && dividend < 0
FixedSizeCodeBlock negative_divisor_negative_dividend(_masm, 8, true);
__ push(LR);
__ rsb(dividend, dividend, 0);
__ rsb(divisor, divisor, 0);
__ bl(positive_arguments);
__ rsb(remainder, remainder, 0);
__ pop(PC);
}
__ bind(call_slow_path);
__ call(CAST_FROM_FN_PTR(address, SharedRuntime::continuation_for_implicit_exception));
__ pop(saved_registers);
__ bx(R0);
return start;
}
// As per atomic.hpp the Atomic read-modify-write operations must be logically implemented as:
// <fence>; <op>; <membar StoreLoad|StoreStore>
// But for load-linked/store-conditional based systems a fence here simply means
// no load/store can be reordered with respect to the initial load-linked, so we have:
// <membar storeload|loadload> ; load-linked; <op>; store-conditional; <membar storeload|storestore>
// There are no memory actions in <op> so nothing further is needed.
//
// So we define the following for convenience:
#define MEMBAR_ATOMIC_OP_PRE \
MacroAssembler::Membar_mask_bits(MacroAssembler::StoreLoad|MacroAssembler::LoadLoad)
#define MEMBAR_ATOMIC_OP_POST \
MacroAssembler::Membar_mask_bits(MacroAssembler::StoreLoad|MacroAssembler::StoreStore)
// Note: JDK 9 only supports ARMv7+ so we always have ldrexd available even though the
// code below allows for it to be otherwise. The else clause indicates an ARMv5 system
// for which we do not support MP and so membars are not necessary. This ARMv5 code will
// be removed in the future.
// Implementation of atomic_add(jint add_value, volatile jint* dest)
// used by Atomic::add(volatile jint* dest, jint add_value)
//
// Arguments :
//
// add_value: R0
// dest: R1
//
// Results:
//
// R0: the new stored in dest
//
// Overwrites:
//
// R1, R2, R3
//
address generate_atomic_add() {
address start;
StubCodeMark mark(this, "StubRoutines", "atomic_add");
Label retry;
start = __ pc();
Register addval = R0;
Register dest = R1;
Register prev = R2;
Register ok = R2;
Register newval = R3;
if (VM_Version::supports_ldrex()) {
__ membar(MEMBAR_ATOMIC_OP_PRE, prev);
__ bind(retry);
__ ldrex(newval, Address(dest));
__ add(newval, addval, newval);
__ strex(ok, newval, Address(dest));
__ cmp(ok, 0);
__ b(retry, ne);
__ mov (R0, newval);
__ membar(MEMBAR_ATOMIC_OP_POST, prev);
} else {
__ bind(retry);
__ ldr (prev, Address(dest));
__ add(newval, addval, prev);
__ atomic_cas_bool(prev, newval, dest, 0, noreg/*ignored*/);
__ b(retry, ne);
__ mov (R0, newval);
}
__ bx(LR);
return start;
}
// Implementation of jint atomic_xchg(jint exchange_value, volatile jint* dest)
// used by Atomic::add(volatile jint* dest, jint exchange_value)
//
// Arguments :
//
// exchange_value: R0
// dest: R1
//
// Results:
//
// R0: the value previously stored in dest
//
// Overwrites:
//
// R1, R2, R3
//
address generate_atomic_xchg() {
address start;
StubCodeMark mark(this, "StubRoutines", "atomic_xchg");
start = __ pc();
Register newval = R0;
Register dest = R1;
Register prev = R2;
Label retry;
if (VM_Version::supports_ldrex()) {
Register ok=R3;
__ membar(MEMBAR_ATOMIC_OP_PRE, prev);
__ bind(retry);
__ ldrex(prev, Address(dest));
__ strex(ok, newval, Address(dest));
__ cmp(ok, 0);
__ b(retry, ne);
__ mov (R0, prev);
__ membar(MEMBAR_ATOMIC_OP_POST, prev);
} else {
__ bind(retry);
__ ldr (prev, Address(dest));
__ atomic_cas_bool(prev, newval, dest, 0, noreg/*ignored*/);
__ b(retry, ne);
__ mov (R0, prev);
}
__ bx(LR);
return start;
}
// Implementation of jint atomic_cmpxchg(jint exchange_value, volatile jint *dest, jint compare_value)
// used by Atomic::cmpxchg(volatile jint *dest, jint compare_value, jint exchange_value)
//
// Arguments :
//
// compare_value: R0
// exchange_value: R1
// dest: R2
//
// Results:
//
// R0: the value previously stored in dest
//
// Overwrites:
//
// R0, R1, R2, R3, Rtemp
//
address generate_atomic_cmpxchg() {
address start;
StubCodeMark mark(this, "StubRoutines", "atomic_cmpxchg");
start = __ pc();
Register cmp = R0;
Register newval = R1;
Register dest = R2;
Register temp1 = R3;
Register temp2 = Rtemp; // Rtemp free (native ABI)
__ membar(MEMBAR_ATOMIC_OP_PRE, temp1);
// atomic_cas returns previous value in R0
__ atomic_cas(temp1, temp2, cmp, newval, dest, 0);
__ membar(MEMBAR_ATOMIC_OP_POST, temp1);
__ bx(LR);
return start;
}
// Support for jlong Atomic::cmpxchg(jlong exchange_value, volatile jlong *dest, jlong compare_value)
// reordered before by a wrapper to (jlong compare_value, jlong exchange_value, volatile jlong *dest)
//
// Arguments :
//
// compare_value: R1 (High), R0 (Low)
// exchange_value: R3 (High), R2 (Low)
// dest: SP+0
//
// Results:
//
// R0:R1: the value previously stored in dest
//
// Overwrites:
//
address generate_atomic_cmpxchg_long() {
address start;
StubCodeMark mark(this, "StubRoutines", "atomic_cmpxchg_long");
start = __ pc();
Register cmp_lo = R0;
Register cmp_hi = R1;
Register newval_lo = R2;
Register newval_hi = R3;
Register addr = Rtemp; /* After load from stack */
Register temp_lo = R4;
Register temp_hi = R5;
Register temp_result = R8;
assert_different_registers(cmp_lo, newval_lo, temp_lo, addr, temp_result, R7);
assert_different_registers(cmp_hi, newval_hi, temp_hi, addr, temp_result, R7);
__ membar(MEMBAR_ATOMIC_OP_PRE, Rtemp); // Rtemp free (native ABI)
// Stack is unaligned, maintain double word alignment by pushing
// odd number of regs.
__ push(RegisterSet(temp_result) | RegisterSet(temp_lo, temp_hi));
__ ldr(addr, Address(SP, 12));
// atomic_cas64 returns previous value in temp_lo, temp_hi
__ atomic_cas64(temp_lo, temp_hi, temp_result, cmp_lo, cmp_hi,
newval_lo, newval_hi, addr, 0);
__ mov(R0, temp_lo);
__ mov(R1, temp_hi);
__ pop(RegisterSet(temp_result) | RegisterSet(temp_lo, temp_hi));
__ membar(MEMBAR_ATOMIC_OP_POST, Rtemp); // Rtemp free (native ABI)
__ bx(LR);
return start;
}
address generate_atomic_load_long() {
address start;
StubCodeMark mark(this, "StubRoutines", "atomic_load_long");
start = __ pc();
Register result_lo = R0;
Register result_hi = R1;
Register src = R0;
if (!os::is_MP()) {
__ ldmia(src, RegisterSet(result_lo, result_hi));
__ bx(LR);
} else if (VM_Version::supports_ldrexd()) {
__ ldrexd(result_lo, Address(src));
__ clrex(); // FIXME: safe to remove?
__ bx(LR);
} else {
__ stop("Atomic load(jlong) unsupported on this platform");
__ bx(LR);
}
return start;
}
address generate_atomic_store_long() {
address start;
StubCodeMark mark(this, "StubRoutines", "atomic_store_long");
start = __ pc();
Register newval_lo = R0;
Register newval_hi = R1;
Register dest = R2;
Register scratch_lo = R2;
Register scratch_hi = R3; /* After load from stack */
Register result = R3;
if (!os::is_MP()) {
__ stmia(dest, RegisterSet(newval_lo, newval_hi));
__ bx(LR);
} else if (VM_Version::supports_ldrexd()) {
__ mov(Rtemp, dest); // get dest to Rtemp
Label retry;
__ bind(retry);
__ ldrexd(scratch_lo, Address(Rtemp));
__ strexd(result, R0, Address(Rtemp));
__ rsbs(result, result, 1);
__ b(retry, eq);
__ bx(LR);
} else {
__ stop("Atomic store(jlong) unsupported on this platform");
__ bx(LR);
}
return start;
}
#ifdef COMPILER2
// Support for uint StubRoutine::Arm::partial_subtype_check( Klass sub, Klass super );
// Arguments :
//
// ret : R0, returned
// icc/xcc: set as R0 (depending on wordSize)
// sub : R1, argument, not changed
// super: R2, argument, not changed
// raddr: LR, blown by call
address generate_partial_subtype_check() {
__ align(CodeEntryAlignment);
StubCodeMark mark(this, "StubRoutines", "partial_subtype_check");
address start = __ pc();
// based on SPARC check_klass_subtype_[fast|slow]_path (without CompressedOops)
// R0 used as tmp_reg (in addition to return reg)
Register sub_klass = R1;
Register super_klass = R2;
Register tmp_reg2 = R3;
Register tmp_reg3 = R4;
#define saved_set tmp_reg2, tmp_reg3
Label L_loop, L_fail;
int sc_offset = in_bytes(Klass::secondary_super_cache_offset());
// fast check should be redundant
// slow check
{
__ raw_push(saved_set);
// a couple of useful fields in sub_klass:
int ss_offset = in_bytes(Klass::secondary_supers_offset());
// Do a linear scan of the secondary super-klass chain.
// This code is rarely used, so simplicity is a virtue here.
inc_counter_np(SharedRuntime::_partial_subtype_ctr, tmp_reg2, tmp_reg3);
Register scan_temp = tmp_reg2;
Register count_temp = tmp_reg3;
// We will consult the secondary-super array.
__ ldr(scan_temp, Address(sub_klass, ss_offset));
Register search_key = super_klass;
// Load the array length.
__ ldr_s32(count_temp, Address(scan_temp, Array<Klass*>::length_offset_in_bytes()));
__ add(scan_temp, scan_temp, Array<Klass*>::base_offset_in_bytes());
__ add(count_temp, count_temp, 1);
// Top of search loop
__ bind(L_loop);
// Notes:
// scan_temp starts at the array elements
// count_temp is 1+size
__ subs(count_temp, count_temp, 1);
__ b(L_fail, eq); // not found in the array
// Load next super to check
// In the array of super classes elements are pointer sized.
int element_size = wordSize;
__ ldr(R0, Address(scan_temp, element_size, post_indexed));
// Look for Rsuper_klass on Rsub_klass's secondary super-class-overflow list
__ subs(R0, R0, search_key); // set R0 to 0 on success (and flags to eq)
// A miss means we are NOT a subtype and need to keep looping
__ b(L_loop, ne);
// Falling out the bottom means we found a hit; we ARE a subtype
// Success. Cache the super we found and proceed in triumph.
__ str(super_klass, Address(sub_klass, sc_offset));
// Return success
// R0 is already 0 and flags are already set to eq
__ raw_pop(saved_set);
__ ret();
// Return failure
__ bind(L_fail);
__ movs(R0, 1); // sets the flags
__ raw_pop(saved_set);
__ ret();
}
return start;
}
#undef saved_set
#endif // COMPILER2
//----------------------------------------------------------------------------------------------------
// Non-destructive plausibility checks for oops
address generate_verify_oop() {
StubCodeMark mark(this, "StubRoutines", "verify_oop");
address start = __ pc();
// Incoming arguments:
//
// R0: error message (char* )
// R1: address of register save area
// R2: oop to verify
//
// All registers are saved before calling this stub. However, condition flags should be saved here.
const Register oop = R2;
const Register klass = R3;
const Register tmp1 = R6;
const Register tmp2 = R8;
const Register flags = Rtmp_save0; // R4/R19
const Register ret_addr = Rtmp_save1; // R5/R20
assert_different_registers(oop, klass, tmp1, tmp2, flags, ret_addr, R7);
Label exit, error;
InlinedAddress verify_oop_count((address) StubRoutines::verify_oop_count_addr());
__ mrs(Assembler::CPSR, flags);
__ ldr_literal(tmp1, verify_oop_count);
__ ldr_s32(tmp2, Address(tmp1));
__ add(tmp2, tmp2, 1);
__ str_32(tmp2, Address(tmp1));
// make sure object is 'reasonable'
__ cbz(oop, exit); // if obj is NULL it is ok
// Check if the oop is in the right area of memory
// Note: oop_mask and oop_bits must be updated if the code is saved/reused
const address oop_mask = (address) Universe::verify_oop_mask();
const address oop_bits = (address) Universe::verify_oop_bits();
__ mov_address(tmp1, oop_mask);
__ andr(tmp2, oop, tmp1);
__ mov_address(tmp1, oop_bits);
__ cmp(tmp2, tmp1);
__ b(error, ne);
// make sure klass is 'reasonable'
__ load_klass(klass, oop); // get klass
__ cbz(klass, error); // if klass is NULL it is broken
// return if everything seems ok
__ bind(exit);
__ msr(Assembler::CPSR_f, flags);
__ ret();
// handle errors
__ bind(error);
__ mov(ret_addr, LR); // save return address
// R0: error message
// R1: register save area
__ call(CAST_FROM_FN_PTR(address, MacroAssembler::debug));
__ mov(LR, ret_addr);
__ b(exit);
__ bind_literal(verify_oop_count);
return start;
}
//----------------------------------------------------------------------------------------------------
// Array copy stubs
//
// Generate overlap test for array copy stubs
//
// Input:
// R0 - array1
// R1 - array2
// R2 - element count, 32-bit int
//
// input registers are preserved
//
void array_overlap_test(address no_overlap_target, int log2_elem_size, Register tmp1, Register tmp2) {
assert(no_overlap_target != NULL, "must be generated");
array_overlap_test(no_overlap_target, NULL, log2_elem_size, tmp1, tmp2);
}
void array_overlap_test(Label& L_no_overlap, int log2_elem_size, Register tmp1, Register tmp2) {
array_overlap_test(NULL, &L_no_overlap, log2_elem_size, tmp1, tmp2);
}
void array_overlap_test(address no_overlap_target, Label* NOLp, int log2_elem_size, Register tmp1, Register tmp2) {
const Register from = R0;
const Register to = R1;
const Register count = R2;
const Register to_from = tmp1; // to - from
const Register byte_count = (log2_elem_size == 0) ? count : tmp2; // count << log2_elem_size
assert_different_registers(from, to, count, tmp1, tmp2);
// no_overlap version works if 'to' lower (unsigned) than 'from'
// and or 'to' more than (count*size) from 'from'
BLOCK_COMMENT("Array Overlap Test:");
__ subs(to_from, to, from);
if (log2_elem_size != 0) {
__ mov(byte_count, AsmOperand(count, lsl, log2_elem_size));
}
if (NOLp == NULL)
__ b(no_overlap_target,lo);
else
__ b((*NOLp), lo);
__ cmp(to_from, byte_count);
if (NOLp == NULL)
__ b(no_overlap_target, ge);
else
__ b((*NOLp), ge);
}
// probably we should choose between "prefetch-store before or after store", not "before or after load".
void prefetch(Register from, Register to, int offset, int to_delta = 0) {
__ prefetch_read(Address(from, offset));
}
// Generate the inner loop for forward aligned array copy
//
// Arguments
// from: src address, 64 bits aligned
// to: dst address, wordSize aligned
// count: number of elements (32-bit int)
// bytes_per_count: number of bytes for each unit of 'count'
//
// Return the minimum initial value for count
//
// Notes:
// - 'from' aligned on 64-bit (recommended for 32-bit ARM in case this speeds up LDMIA)
// - 'to' aligned on wordSize
// - 'count' must be greater or equal than the returned value
//
// Increases 'from' and 'to' by count*bytes_per_count.
//
// Scratches 'count', R3.
// R4-R10 are preserved (saved/restored).
//
int generate_forward_aligned_copy_loop(Register from, Register to, Register count, int bytes_per_count, bool unsafe_copy = false) {
assert (from == R0 && to == R1 && count == R2, "adjust the implementation below");
const int bytes_per_loop = 8*wordSize; // 8 registers are read and written on every loop iteration
arraycopy_loop_config *config=&arraycopy_configurations[ArmCopyPlatform].forward_aligned;
int pld_offset = config->pld_distance;
const int count_per_loop = bytes_per_loop / bytes_per_count;
bool split_read= config->split_ldm;
bool split_write= config->split_stm;
// XXX optim: use VLDM/VSTM when available (Neon) with PLD
// NEONCopyPLD
// PLD [r1, #0xC0]
// VLDM r1!,{d0-d7}
// VSTM r0!,{d0-d7}
// SUBS r2,r2,#0x40
// BGE NEONCopyPLD
__ push(RegisterSet(R4,R10));
const bool prefetch_before = pld_offset < 0;
const bool prefetch_after = pld_offset > 0;
Label L_skip_pld;
{
// UnsafeCopyMemory page error: continue after ucm
UnsafeCopyMemoryMark ucmm(this, unsafe_copy, true);
// predecrease to exit when there is less than count_per_loop
__ sub_32(count, count, count_per_loop);
if (pld_offset != 0) {
pld_offset = (pld_offset < 0) ? -pld_offset : pld_offset;
prefetch(from, to, 0);
if (prefetch_before) {
// If prefetch is done ahead, final PLDs that overflow the
// copied area can be easily avoided. 'count' is predecreased
// by the prefetch distance to optimize the inner loop and the
// outer loop skips the PLD.
__ subs_32(count, count, (bytes_per_loop+pld_offset)/bytes_per_count);
// skip prefetch for small copies
__ b(L_skip_pld, lt);
}
int offset = ArmCopyCacheLineSize;
while (offset <= pld_offset) {
prefetch(from, to, offset);
offset += ArmCopyCacheLineSize;
};
}
{
// 32-bit ARM note: we have tried implementing loop unrolling to skip one
// PLD with 64 bytes cache line but the gain was not significant.
Label L_copy_loop;
__ align(OptoLoopAlignment);
__ BIND(L_copy_loop);
if (prefetch_before) {
prefetch(from, to, bytes_per_loop + pld_offset);
__ BIND(L_skip_pld);
}
if (split_read) {
// Split the register set in two sets so that there is less
// latency between LDM and STM (R3-R6 available while R7-R10
// still loading) and less register locking issue when iterating
// on the first LDM.
__ ldmia(from, RegisterSet(R3, R6), writeback);
__ ldmia(from, RegisterSet(R7, R10), writeback);
} else {
__ ldmia(from, RegisterSet(R3, R10), writeback);
}
__ subs_32(count, count, count_per_loop);
if (prefetch_after) {
prefetch(from, to, pld_offset, bytes_per_loop);
}
if (split_write) {
__ stmia(to, RegisterSet(R3, R6), writeback);
__ stmia(to, RegisterSet(R7, R10), writeback);
} else {
__ stmia(to, RegisterSet(R3, R10), writeback);
}
__ b(L_copy_loop, ge);
if (prefetch_before) {
// the inner loop may end earlier, allowing to skip PLD for the last iterations
__ cmn_32(count, (bytes_per_loop + pld_offset)/bytes_per_count);
__ b(L_skip_pld, ge);
}
}
BLOCK_COMMENT("Remaining bytes:");
// still 0..bytes_per_loop-1 aligned bytes to copy, count already decreased by (at least) bytes_per_loop bytes
// __ add(count, count, ...); // addition useless for the bit tests
assert (pld_offset % bytes_per_loop == 0, "decreasing count by pld_offset before loop must not change tested bits");
__ tst(count, 16 / bytes_per_count);
__ ldmia(from, RegisterSet(R3, R6), writeback, ne); // copy 16 bytes
__ stmia(to, RegisterSet(R3, R6), writeback, ne);
__ tst(count, 8 / bytes_per_count);
__ ldmia(from, RegisterSet(R3, R4), writeback, ne); // copy 8 bytes
__ stmia(to, RegisterSet(R3, R4), writeback, ne);
if (bytes_per_count <= 4) {
__ tst(count, 4 / bytes_per_count);
__ ldr(R3, Address(from, 4, post_indexed), ne); // copy 4 bytes
__ str(R3, Address(to, 4, post_indexed), ne);
}
if (bytes_per_count <= 2) {
__ tst(count, 2 / bytes_per_count);
__ ldrh(R3, Address(from, 2, post_indexed), ne); // copy 2 bytes
__ strh(R3, Address(to, 2, post_indexed), ne);
}
if (bytes_per_count == 1) {
__ tst(count, 1);
__ ldrb(R3, Address(from, 1, post_indexed), ne);
__ strb(R3, Address(to, 1, post_indexed), ne);
}
}
__ pop(RegisterSet(R4,R10));
return count_per_loop;
}
// Generate the inner loop for backward aligned array copy
//
// Arguments
// end_from: src end address, 64 bits aligned
// end_to: dst end address, wordSize aligned
// count: number of elements (32-bit int)
// bytes_per_count: number of bytes for each unit of 'count'
//
// Return the minimum initial value for count
//
// Notes:
// - 'end_from' aligned on 64-bit (recommended for 32-bit ARM in case this speeds up LDMIA)
// - 'end_to' aligned on wordSize
// - 'count' must be greater or equal than the returned value
//
// Decreases 'end_from' and 'end_to' by count*bytes_per_count.
//
// Scratches 'count', R3.
// ARM R4-R10 are preserved (saved/restored).
//
int generate_backward_aligned_copy_loop(Register end_from, Register end_to, Register count, int bytes_per_count, bool unsafe_copy = false) {
assert (end_from == R0 && end_to == R1 && count == R2, "adjust the implementation below");
const int bytes_per_loop = 8*wordSize; // 8 registers are read and written on every loop iteration
const int count_per_loop = bytes_per_loop / bytes_per_count;
arraycopy_loop_config *config=&arraycopy_configurations[ArmCopyPlatform].backward_aligned;
int pld_offset = config->pld_distance;
bool split_read= config->split_ldm;
bool split_write= config->split_stm;
// See the forward copy variant for additional comments.
__ push(RegisterSet(R4,R10));
{
// UnsafeCopyMemory page error: continue after ucm
UnsafeCopyMemoryMark ucmm(this, unsafe_copy, true);
__ sub_32(count, count, count_per_loop);
const bool prefetch_before = pld_offset < 0;
const bool prefetch_after = pld_offset > 0;
Label L_skip_pld;
if (pld_offset != 0) {
pld_offset = (pld_offset < 0) ? -pld_offset : pld_offset;
prefetch(end_from, end_to, -wordSize);
if (prefetch_before) {
__ subs_32(count, count, (bytes_per_loop + pld_offset) / bytes_per_count);
__ b(L_skip_pld, lt);
}
int offset = ArmCopyCacheLineSize;
while (offset <= pld_offset) {
prefetch(end_from, end_to, -(wordSize + offset));
offset += ArmCopyCacheLineSize;
};
}
{
// 32-bit ARM note: we have tried implementing loop unrolling to skip one
// PLD with 64 bytes cache line but the gain was not significant.
Label L_copy_loop;
__ align(OptoLoopAlignment);
__ BIND(L_copy_loop);
if (prefetch_before) {
prefetch(end_from, end_to, -(wordSize + bytes_per_loop + pld_offset));
__ BIND(L_skip_pld);
}
if (split_read) {
__ ldmdb(end_from, RegisterSet(R7, R10), writeback);
__ ldmdb(end_from, RegisterSet(R3, R6), writeback);
} else {
__ ldmdb(end_from, RegisterSet(R3, R10), writeback);
}
__ subs_32(count, count, count_per_loop);
if (prefetch_after) {
prefetch(end_from, end_to, -(wordSize + pld_offset), -bytes_per_loop);
}
if (split_write) {
__ stmdb(end_to, RegisterSet(R7, R10), writeback);
__ stmdb(end_to, RegisterSet(R3, R6), writeback);
} else {
__ stmdb(end_to, RegisterSet(R3, R10), writeback);
}
__ b(L_copy_loop, ge);
if (prefetch_before) {
__ cmn_32(count, (bytes_per_loop + pld_offset)/bytes_per_count);
__ b(L_skip_pld, ge);
}
}
BLOCK_COMMENT("Remaining bytes:");
// still 0..bytes_per_loop-1 aligned bytes to copy, count already decreased by (at least) bytes_per_loop bytes
// __ add(count, count, ...); // addition useless for the bit tests
assert (pld_offset % bytes_per_loop == 0, "decreasing count by pld_offset before loop must not change tested bits");
__ tst(count, 16 / bytes_per_count);
__ ldmdb(end_from, RegisterSet(R3, R6), writeback, ne); // copy 16 bytes
__ stmdb(end_to, RegisterSet(R3, R6), writeback, ne);
__ tst(count, 8 / bytes_per_count);
__ ldmdb(end_from, RegisterSet(R3, R4), writeback, ne); // copy 8 bytes
__ stmdb(end_to, RegisterSet(R3, R4), writeback, ne);
if (bytes_per_count <= 4) {
__ tst(count, 4 / bytes_per_count);
__ ldr(R3, Address(end_from, -4, pre_indexed), ne); // copy 4 bytes
__ str(R3, Address(end_to, -4, pre_indexed), ne);
}
if (bytes_per_count <= 2) {
__ tst(count, 2 / bytes_per_count);
__ ldrh(R3, Address(end_from, -2, pre_indexed), ne); // copy 2 bytes
__ strh(R3, Address(end_to, -2, pre_indexed), ne);
}
if (bytes_per_count == 1) {
__ tst(count, 1);
__ ldrb(R3, Address(end_from, -1, pre_indexed), ne);
__ strb(R3, Address(end_to, -1, pre_indexed), ne);
}
}
__ pop(RegisterSet(R4,R10));
return count_per_loop;
}
// Generate the inner loop for shifted forward array copy (unaligned copy).
// It can be used when bytes_per_count < wordSize, i.e. byte/short copy
//
// Arguments
// from: start src address, 64 bits aligned
// to: start dst address, (now) wordSize aligned
// count: number of elements (32-bit int)
// bytes_per_count: number of bytes for each unit of 'count'
// lsr_shift: shift applied to 'old' value to skipped already written bytes
// lsl_shift: shift applied to 'new' value to set the high bytes of the next write
//
// Return the minimum initial value for count
//
// Notes:
// - 'from' aligned on 64-bit (recommended for 32-bit ARM in case this speeds up LDMIA)
// - 'to' aligned on wordSize
// - 'count' must be greater or equal than the returned value
// - 'lsr_shift' + 'lsl_shift' = BitsPerWord
// - 'bytes_per_count' is 1 or 2
//
// Increases 'to' by count*bytes_per_count.
//
// Scratches 'from' and 'count', R3-R10, R12
//
// On entry:
// - R12 is preloaded with the first 'BitsPerWord' bits read just before 'from'
// - (R12 >> lsr_shift) is the part not yet written (just before 'to')
// --> (*to) = (R12 >> lsr_shift) | (*from) << lsl_shift); ...
//
// This implementation may read more bytes than required.
// Actually, it always reads exactly all data from the copied region with upper bound aligned up by wordSize,
// so excessive read do not cross a word bound and is thus harmless.
//
int generate_forward_shifted_copy_loop(Register from, Register to, Register count, int bytes_per_count, int lsr_shift, int lsl_shift) {
assert (from == R0 && to == R1 && count == R2, "adjust the implementation below");
const int bytes_per_loop = 8*wordSize; // 8 registers are read and written on every loop iter
const int count_per_loop = bytes_per_loop / bytes_per_count;
arraycopy_loop_config *config=&arraycopy_configurations[ArmCopyPlatform].forward_shifted;
int pld_offset = config->pld_distance;
bool split_read= config->split_ldm;
bool split_write= config->split_stm;
const bool prefetch_before = pld_offset < 0;
const bool prefetch_after = pld_offset > 0;
Label L_skip_pld, L_last_read, L_done;
if (pld_offset != 0) {
pld_offset = (pld_offset < 0) ? -pld_offset : pld_offset;
prefetch(from, to, 0);
if (prefetch_before) {
__ cmp_32(count, count_per_loop);
__ b(L_last_read, lt);
// skip prefetch for small copies
// warning: count is predecreased by the prefetch distance to optimize the inner loop
__ subs_32(count, count, ((bytes_per_loop + pld_offset) / bytes_per_count) + count_per_loop);
__ b(L_skip_pld, lt);
}
int offset = ArmCopyCacheLineSize;
while (offset <= pld_offset) {
prefetch(from, to, offset);
offset += ArmCopyCacheLineSize;
};
}
Label L_shifted_loop;
__ align(OptoLoopAlignment);
__ BIND(L_shifted_loop);
if (prefetch_before) {
// do it early if there might be register locking issues
prefetch(from, to, bytes_per_loop + pld_offset);
__ BIND(L_skip_pld);
} else {
__ cmp_32(count, count_per_loop);
__ b(L_last_read, lt);
}
// read 32 bytes
if (split_read) {
// if write is not split, use less registers in first set to reduce locking
RegisterSet set1 = split_write ? RegisterSet(R4, R7) : RegisterSet(R4, R5);
RegisterSet set2 = (split_write ? RegisterSet(R8, R10) : RegisterSet(R6, R10)) | R12;
__ ldmia(from, set1, writeback);
__ mov(R3, AsmOperand(R12, lsr, lsr_shift)); // part of R12 not yet written
__ ldmia(from, set2, writeback);
__ subs(count, count, count_per_loop); // XXX: should it be before the 2nd LDM ? (latency vs locking)
} else {
__ mov(R3, AsmOperand(R12, lsr, lsr_shift)); // part of R12 not yet written
__ ldmia(from, RegisterSet(R4, R10) | R12, writeback); // Note: small latency on R4
__ subs(count, count, count_per_loop);
}
if (prefetch_after) {
// do it after the 1st ldm/ldp anyway (no locking issues with early STM/STP)
prefetch(from, to, pld_offset, bytes_per_loop);
}
// prepare (shift) the values in R3..R10
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift)); // merged below low bytes of next val
__ logical_shift_right(R4, R4, lsr_shift); // unused part of next val
__ orr(R4, R4, AsmOperand(R5, lsl, lsl_shift)); // ...
__ logical_shift_right(R5, R5, lsr_shift);
__ orr(R5, R5, AsmOperand(R6, lsl, lsl_shift));
__ logical_shift_right(R6, R6, lsr_shift);
__ orr(R6, R6, AsmOperand(R7, lsl, lsl_shift));
if (split_write) {
// write the first half as soon as possible to reduce stm locking
__ stmia(to, RegisterSet(R3, R6), writeback, prefetch_before ? gt : ge);
}
__ logical_shift_right(R7, R7, lsr_shift);
__ orr(R7, R7, AsmOperand(R8, lsl, lsl_shift));
__ logical_shift_right(R8, R8, lsr_shift);
__ orr(R8, R8, AsmOperand(R9, lsl, lsl_shift));
__ logical_shift_right(R9, R9, lsr_shift);
__ orr(R9, R9, AsmOperand(R10, lsl, lsl_shift));
__ logical_shift_right(R10, R10, lsr_shift);
__ orr(R10, R10, AsmOperand(R12, lsl, lsl_shift));
if (split_write) {
__ stmia(to, RegisterSet(R7, R10), writeback, prefetch_before ? gt : ge);
} else {
__ stmia(to, RegisterSet(R3, R10), writeback, prefetch_before ? gt : ge);
}
__ b(L_shifted_loop, gt); // no need to loop if 0 (when count need not be precise modulo bytes_per_loop)
if (prefetch_before) {
// the first loop may end earlier, allowing to skip pld at the end
__ cmn_32(count, (bytes_per_loop + pld_offset)/bytes_per_count);
__ stmia(to, RegisterSet(R3, R10), writeback); // stmia was skipped
__ b(L_skip_pld, ge);
__ adds_32(count, count, ((bytes_per_loop + pld_offset) / bytes_per_count) + count_per_loop);
}
__ BIND(L_last_read);
__ b(L_done, eq);
switch (bytes_per_count) {
case 2:
__ mov(R3, AsmOperand(R12, lsr, lsr_shift));
__ tst(count, 8);
__ ldmia(from, RegisterSet(R4, R7), writeback, ne);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ne); // merged below low bytes of next val
__ mov(R4, AsmOperand(R4, lsr, lsr_shift), ne); // unused part of next val
__ orr(R4, R4, AsmOperand(R5, lsl, lsl_shift), ne); // ...
__ mov(R5, AsmOperand(R5, lsr, lsr_shift), ne);
__ orr(R5, R5, AsmOperand(R6, lsl, lsl_shift), ne);
__ mov(R6, AsmOperand(R6, lsr, lsr_shift), ne);
__ orr(R6, R6, AsmOperand(R7, lsl, lsl_shift), ne);
__ stmia(to, RegisterSet(R3, R6), writeback, ne);
__ mov(R3, AsmOperand(R7, lsr, lsr_shift), ne);
__ tst(count, 4);
__ ldmia(from, RegisterSet(R4, R5), writeback, ne);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ne); // merged below low bytes of next val
__ mov(R4, AsmOperand(R4, lsr, lsr_shift), ne); // unused part of next val
__ orr(R4, R4, AsmOperand(R5, lsl, lsl_shift), ne); // ...
__ stmia(to, RegisterSet(R3, R4), writeback, ne);
__ mov(R3, AsmOperand(R5, lsr, lsr_shift), ne);
__ tst(count, 2);
__ ldr(R4, Address(from, 4, post_indexed), ne);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ne);
__ str(R3, Address(to, 4, post_indexed), ne);
__ mov(R3, AsmOperand(R4, lsr, lsr_shift), ne);
__ tst(count, 1);
__ strh(R3, Address(to, 2, post_indexed), ne); // one last short
break;
case 1:
__ mov(R3, AsmOperand(R12, lsr, lsr_shift));
__ tst(count, 16);
__ ldmia(from, RegisterSet(R4, R7), writeback, ne);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ne); // merged below low bytes of next val
__ mov(R4, AsmOperand(R4, lsr, lsr_shift), ne); // unused part of next val
__ orr(R4, R4, AsmOperand(R5, lsl, lsl_shift), ne); // ...
__ mov(R5, AsmOperand(R5, lsr, lsr_shift), ne);
__ orr(R5, R5, AsmOperand(R6, lsl, lsl_shift), ne);
__ mov(R6, AsmOperand(R6, lsr, lsr_shift), ne);
__ orr(R6, R6, AsmOperand(R7, lsl, lsl_shift), ne);
__ stmia(to, RegisterSet(R3, R6), writeback, ne);
__ mov(R3, AsmOperand(R7, lsr, lsr_shift), ne);
__ tst(count, 8);
__ ldmia(from, RegisterSet(R4, R5), writeback, ne);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ne); // merged below low bytes of next val
__ mov(R4, AsmOperand(R4, lsr, lsr_shift), ne); // unused part of next val
__ orr(R4, R4, AsmOperand(R5, lsl, lsl_shift), ne); // ...
__ stmia(to, RegisterSet(R3, R4), writeback, ne);
__ mov(R3, AsmOperand(R5, lsr, lsr_shift), ne);
__ tst(count, 4);
__ ldr(R4, Address(from, 4, post_indexed), ne);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ne);
__ str(R3, Address(to, 4, post_indexed), ne);
__ mov(R3, AsmOperand(R4, lsr, lsr_shift), ne);
__ andr(count, count, 3);
__ cmp(count, 2);
// Note: R3 might contain enough bytes ready to write (3 needed at most),
// thus load on lsl_shift==24 is not needed (in fact forces reading
// beyond source buffer end boundary)
if (lsl_shift == 8) {
__ ldr(R4, Address(from, 4, post_indexed), ge);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), ge);
} else if (lsl_shift == 16) {
__ ldr(R4, Address(from, 4, post_indexed), gt);
__ orr(R3, R3, AsmOperand(R4, lsl, lsl_shift), gt);
}
__ strh(R3, Address(to, 2, post_indexed), ge); // two last bytes
__ mov(R3, AsmOperand(R3, lsr, 16), gt);
__ tst(count, 1);
__ strb(R3, Address(to, 1, post_indexed), ne); // one last byte
break;
}
__ BIND(L_done);
return 0; // no minimum
}
// Generate the inner loop for shifted backward array copy (unaligned copy).
// It can be used when bytes_per_count < wordSize, i.e. byte/short copy
//
// Arguments
// end_from: end src address, 64 bits aligned
// end_to: end dst address, (now) wordSize aligned
// count: number of elements (32-bit int)
// bytes_per_count: number of bytes for each unit of 'count'
// lsl_shift: shift applied to 'old' value to skipped already written bytes
// lsr_shift: shift applied to 'new' value to set the low bytes of the next write
//
// Return the minimum initial value for count
//
// Notes:
// - 'end_from' aligned on 64-bit (recommended for 32-bit ARM in case this speeds up LDMIA)
// - 'end_to' aligned on wordSize
// - 'count' must be greater or equal than the returned value
// - 'lsr_shift' + 'lsl_shift' = 'BitsPerWord'
// - 'bytes_per_count' is 1 or 2 on 32-bit ARM
//
// Decreases 'end_to' by count*bytes_per_count.
//
// Scratches 'end_from', 'count', R3-R10, R12
//
// On entry:
// - R3 is preloaded with the first 'BitsPerWord' bits read just after 'from'
// - (R3 << lsl_shift) is the part not yet written
// --> (*--to) = (R3 << lsl_shift) | (*--from) >> lsr_shift); ...
//
// This implementation may read more bytes than required.
// Actually, it always reads exactly all data from the copied region with beginning aligned down by wordSize,
// so excessive read do not cross a word bound and is thus harmless.
//
int generate_backward_shifted_copy_loop(Register end_from, Register end_to, Register count, int bytes_per_count, int lsr_shift, int lsl_shift) {
assert (end_from == R0 && end_to == R1 && count == R2, "adjust the implementation below");
const int bytes_per_loop = 8*wordSize; // 8 registers are read and written on every loop iter
const int count_per_loop = bytes_per_loop / bytes_per_count;
arraycopy_loop_config *config=&arraycopy_configurations[ArmCopyPlatform].backward_shifted;
int pld_offset = config->pld_distance;
bool split_read= config->split_ldm;
bool split_write= config->split_stm;
const bool prefetch_before = pld_offset < 0;
const bool prefetch_after = pld_offset > 0;
Label L_skip_pld, L_done, L_last_read;
if (pld_offset != 0) {
pld_offset = (pld_offset < 0) ? -pld_offset : pld_offset;
prefetch(end_from, end_to, -wordSize);
if (prefetch_before) {
__ cmp_32(count, count_per_loop);
__ b(L_last_read, lt);
// skip prefetch for small copies
// warning: count is predecreased by the prefetch distance to optimize the inner loop
__ subs_32(count, count, ((bytes_per_loop + pld_offset)/bytes_per_count) + count_per_loop);
__ b(L_skip_pld, lt);
}
int offset = ArmCopyCacheLineSize;
while (offset <= pld_offset) {
prefetch(end_from, end_to, -(wordSize + offset));
offset += ArmCopyCacheLineSize;
};
}
Label L_shifted_loop;
__ align(OptoLoopAlignment);
__ BIND(L_shifted_loop);
if (prefetch_before) {
// do the 1st ldm/ldp first anyway (no locking issues with early STM/STP)
prefetch(end_from, end_to, -(wordSize + bytes_per_loop + pld_offset));
__ BIND(L_skip_pld);
} else {
__ cmp_32(count, count_per_loop);
__ b(L_last_read, lt);
}
if (split_read) {
__ ldmdb(end_from, RegisterSet(R7, R10), writeback);
__ mov(R12, AsmOperand(R3, lsl, lsl_shift)); // part of R3 not yet written
__ ldmdb(end_from, RegisterSet(R3, R6), writeback);
} else {
__ mov(R12, AsmOperand(R3, lsl, lsl_shift)); // part of R3 not yet written
__ ldmdb(end_from, RegisterSet(R3, R10), writeback);
}
__ subs_32(count, count, count_per_loop);
if (prefetch_after) { // do prefetch during ldm/ldp latency
prefetch(end_from, end_to, -(wordSize + pld_offset), -bytes_per_loop);
}
// prepare the values in R4..R10,R12
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift)); // merged above high bytes of prev val
__ logical_shift_left(R10, R10, lsl_shift); // unused part of prev val
__ orr(R10, R10, AsmOperand(R9, lsr, lsr_shift)); // ...
__ logical_shift_left(R9, R9, lsl_shift);
__ orr(R9, R9, AsmOperand(R8, lsr, lsr_shift));
__ logical_shift_left(R8, R8, lsl_shift);
__ orr(R8, R8, AsmOperand(R7, lsr, lsr_shift));
__ logical_shift_left(R7, R7, lsl_shift);
__ orr(R7, R7, AsmOperand(R6, lsr, lsr_shift));
__ logical_shift_left(R6, R6, lsl_shift);
__ orr(R6, R6, AsmOperand(R5, lsr, lsr_shift));
if (split_write) {
// store early to reduce locking issues
__ stmdb(end_to, RegisterSet(R6, R10) | R12, writeback, prefetch_before ? gt : ge);
}
__ logical_shift_left(R5, R5, lsl_shift);
__ orr(R5, R5, AsmOperand(R4, lsr, lsr_shift));
__ logical_shift_left(R4, R4, lsl_shift);
__ orr(R4, R4, AsmOperand(R3, lsr, lsr_shift));
if (split_write) {
__ stmdb(end_to, RegisterSet(R4, R5), writeback, prefetch_before ? gt : ge);
} else {
__ stmdb(end_to, RegisterSet(R4, R10) | R12, writeback, prefetch_before ? gt : ge);
}
__ b(L_shifted_loop, gt); // no need to loop if 0 (when count need not be precise modulo bytes_per_loop)
if (prefetch_before) {
// the first loop may end earlier, allowing to skip pld at the end
__ cmn_32(count, ((bytes_per_loop + pld_offset)/bytes_per_count));
__ stmdb(end_to, RegisterSet(R4, R10) | R12, writeback); // stmdb was skipped
__ b(L_skip_pld, ge);
__ adds_32(count, count, ((bytes_per_loop + pld_offset) / bytes_per_count) + count_per_loop);
}
__ BIND(L_last_read);
__ b(L_done, eq);
switch(bytes_per_count) {
case 2:
__ mov(R12, AsmOperand(R3, lsl, lsl_shift)); // part of R3 not yet written
__ tst(count, 8);
__ ldmdb(end_from, RegisterSet(R7,R10), writeback, ne);
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift), ne);
__ mov(R10, AsmOperand(R10, lsl, lsl_shift),ne); // unused part of prev val
__ orr(R10, R10, AsmOperand(R9, lsr, lsr_shift),ne); // ...
__ mov(R9, AsmOperand(R9, lsl, lsl_shift),ne);
__ orr(R9, R9, AsmOperand(R8, lsr, lsr_shift),ne);
__ mov(R8, AsmOperand(R8, lsl, lsl_shift),ne);
__ orr(R8, R8, AsmOperand(R7, lsr, lsr_shift),ne);
__ stmdb(end_to, RegisterSet(R8,R10)|R12, writeback, ne);
__ mov(R12, AsmOperand(R7, lsl, lsl_shift), ne);
__ tst(count, 4);
__ ldmdb(end_from, RegisterSet(R9, R10), writeback, ne);
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift), ne);
__ mov(R10, AsmOperand(R10, lsl, lsl_shift),ne); // unused part of prev val
__ orr(R10, R10, AsmOperand(R9, lsr,lsr_shift),ne); // ...
__ stmdb(end_to, RegisterSet(R10)|R12, writeback, ne);
__ mov(R12, AsmOperand(R9, lsl, lsl_shift), ne);
__ tst(count, 2);
__ ldr(R10, Address(end_from, -4, pre_indexed), ne);
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift), ne);
__ str(R12, Address(end_to, -4, pre_indexed), ne);
__ mov(R12, AsmOperand(R10, lsl, lsl_shift), ne);
__ tst(count, 1);
__ mov(R12, AsmOperand(R12, lsr, lsr_shift),ne);
__ strh(R12, Address(end_to, -2, pre_indexed), ne); // one last short
break;
case 1:
__ mov(R12, AsmOperand(R3, lsl, lsl_shift)); // part of R3 not yet written
__ tst(count, 16);
__ ldmdb(end_from, RegisterSet(R7,R10), writeback, ne);
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift), ne);
__ mov(R10, AsmOperand(R10, lsl, lsl_shift),ne); // unused part of prev val
__ orr(R10, R10, AsmOperand(R9, lsr, lsr_shift),ne); // ...
__ mov(R9, AsmOperand(R9, lsl, lsl_shift),ne);
__ orr(R9, R9, AsmOperand(R8, lsr, lsr_shift),ne);
__ mov(R8, AsmOperand(R8, lsl, lsl_shift),ne);
__ orr(R8, R8, AsmOperand(R7, lsr, lsr_shift),ne);
__ stmdb(end_to, RegisterSet(R8,R10)|R12, writeback, ne);
__ mov(R12, AsmOperand(R7, lsl, lsl_shift), ne);
__ tst(count, 8);
__ ldmdb(end_from, RegisterSet(R9,R10), writeback, ne);
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift), ne);
__ mov(R10, AsmOperand(R10, lsl, lsl_shift),ne); // unused part of prev val
__ orr(R10, R10, AsmOperand(R9, lsr, lsr_shift),ne); // ...
__ stmdb(end_to, RegisterSet(R10)|R12, writeback, ne);
__ mov(R12, AsmOperand(R9, lsl, lsl_shift), ne);
__ tst(count, 4);
__ ldr(R10, Address(end_from, -4, pre_indexed), ne);
__ orr(R12, R12, AsmOperand(R10, lsr, lsr_shift), ne);
__ str(R12, Address(end_to, -4, pre_indexed), ne);
__ mov(R12, AsmOperand(R10, lsl, lsl_shift), ne);
__ tst(count, 2);
if (lsr_shift != 24) {
// avoid useless reading R10 when we already have 3 bytes ready in R12
__ ldr(R10, Address(end_from, -4, pre_indexed), ne);
__ orr(R12, R12, AsmOperand(R10, lsr,lsr_shift), ne);
}
// Note: R12 contains enough bytes ready to write (3 needed at most)
// write the 2 MSBs
__ mov(R9, AsmOperand(R12, lsr, 16), ne);
__ strh(R9, Address(end_to, -2, pre_indexed), ne);
// promote remaining to MSB
__ mov(R12, AsmOperand(R12, lsl, 16), ne);
__ tst(count, 1);
// write the MSB of R12
__ mov(R12, AsmOperand(R12, lsr, 24), ne);
__ strb(R12, Address(end_to, -1, pre_indexed), ne);
break;
}
__ BIND(L_done);
return 0; // no minimum
}
// This method is very useful for merging forward/backward implementations
Address get_addr_with_indexing(Register base, int delta, bool forward) {
if (forward) {
return Address(base, delta, post_indexed);
} else {
return Address(base, -delta, pre_indexed);
}
}
void load_one(Register rd, Register from, int size_in_bytes, bool forward, AsmCondition cond = al, Register rd2 = noreg) {
assert_different_registers(from, rd, rd2);
if (size_in_bytes < 8) {
Address addr = get_addr_with_indexing(from, size_in_bytes, forward);
__ load_sized_value(rd, addr, size_in_bytes, false, cond);
} else {
assert (rd2 != noreg, "second value register must be specified");
assert (rd->encoding() < rd2->encoding(), "wrong value register set");
if (forward) {
__ ldmia(from, RegisterSet(rd) | rd2, writeback, cond);
} else {
__ ldmdb(from, RegisterSet(rd) | rd2, writeback, cond);
}
}
}
void store_one(Register rd, Register to, int size_in_bytes, bool forward, AsmCondition cond = al, Register rd2 = noreg) {
assert_different_registers(to, rd, rd2);
if (size_in_bytes < 8) {
Address addr = get_addr_with_indexing(to, size_in_bytes, forward);
__ store_sized_value(rd, addr, size_in_bytes, cond);
} else {
assert (rd2 != noreg, "second value register must be specified");
assert (rd->encoding() < rd2->encoding(), "wrong value register set");
if (forward) {
__ stmia(to, RegisterSet(rd) | rd2, writeback, cond);
} else {
__ stmdb(to, RegisterSet(rd) | rd2, writeback, cond);
}
}
}
// Copies data from 'from' to 'to' in specified direction to align 'from' by 64 bits.
// (on 32-bit ARM 64-bit alignment is better for LDM).
//
// Arguments:
// from: beginning (if forward) or upper bound (if !forward) of the region to be read
// to: beginning (if forward) or upper bound (if !forward) of the region to be written
// count: 32-bit int, maximum number of elements which can be copied
// bytes_per_count: size of an element
// forward: specifies copy direction
//
// Notes:
// 'from' and 'to' must be aligned by 'bytes_per_count'
// 'count' must not be less than the returned value
// shifts 'from' and 'to' by the number of copied bytes in corresponding direction
// decreases 'count' by the number of elements copied
//
// Returns maximum number of bytes which may be copied.
int align_src(Register from, Register to, Register count, Register tmp, int bytes_per_count, bool forward) {
assert_different_registers(from, to, count, tmp);
if (bytes_per_count < 8) {
Label L_align_src;
__ BIND(L_align_src);
__ tst(from, 7);
// ne => not aligned: copy one element and (if bytes_per_count < 4) loop
__ sub(count, count, 1, ne);
load_one(tmp, from, bytes_per_count, forward, ne);
store_one(tmp, to, bytes_per_count, forward, ne);
if (bytes_per_count < 4) {
__ b(L_align_src, ne); // if bytes_per_count == 4, then 0 or 1 loop iterations are enough
}
}
return 7/bytes_per_count;
}
// Copies 'count' of 'bytes_per_count'-sized elements in the specified direction.
//
// Arguments:
// from: beginning (if forward) or upper bound (if !forward) of the region to be read
// to: beginning (if forward) or upper bound (if !forward) of the region to be written
// count: 32-bit int, number of elements to be copied
// entry: copy loop entry point
// bytes_per_count: size of an element
// forward: specifies copy direction
//
// Notes:
// shifts 'from' and 'to'
void copy_small_array(Register from, Register to, Register count, Register tmp, Register tmp2, int bytes_per_count, bool forward, Label & entry, bool unsafe_copy = false) {
assert_different_registers(from, to, count, tmp);
{
// UnsafeCopyMemory page error: continue after ucm
UnsafeCopyMemoryMark ucmm(this, unsafe_copy, true);
__ align(OptoLoopAlignment);
Label L_small_loop;
__ BIND(L_small_loop);
store_one(tmp, to, bytes_per_count, forward, al, tmp2);
__ BIND(entry); // entry point
__ subs(count, count, 1);
load_one(tmp, from, bytes_per_count, forward, ge, tmp2);
__ b(L_small_loop, ge);
}
}
// Aligns 'to' by reading one word from 'from' and writting its part to 'to'.
//
// Arguments:
// to: beginning (if forward) or upper bound (if !forward) of the region to be written
// count: 32-bit int, number of elements allowed to be copied
// to_remainder: remainder of dividing 'to' by wordSize
// bytes_per_count: size of an element
// forward: specifies copy direction
// Rval: contains an already read but not yet written word;
// its' LSBs (if forward) or MSBs (if !forward) are to be written to align 'to'.
//
// Notes:
// 'count' must not be less then the returned value
// 'to' must be aligned by bytes_per_count but must not be aligned by wordSize
// shifts 'to' by the number of written bytes (so that it becomes the bound of memory to be written)
// decreases 'count' by the the number of elements written
// Rval's MSBs or LSBs remain to be written further by generate_{forward,backward}_shifted_copy_loop
int align_dst(Register to, Register count, Register Rval, Register tmp,
int to_remainder, int bytes_per_count, bool forward) {
assert_different_registers(to, count, tmp, Rval);
assert (0 < to_remainder && to_remainder < wordSize, "to_remainder is not valid");
assert (to_remainder % bytes_per_count == 0, "to must be aligned by bytes_per_count");
int bytes_to_write = forward ? (wordSize - to_remainder) : to_remainder;
int offset = 0;
for (int l = 0; l < LogBytesPerWord; ++l) {
int s = (1 << l);
if (bytes_to_write & s) {
int new_offset = offset + s*BitsPerByte;
if (forward) {
if (offset == 0) {
store_one(Rval, to, s, forward);
} else {
__ logical_shift_right(tmp, Rval, offset);
store_one(tmp, to, s, forward);
}
} else {
__ logical_shift_right(tmp, Rval, BitsPerWord - new_offset);
store_one(tmp, to, s, forward);
}
offset = new_offset;
}
}
assert (offset == bytes_to_write * BitsPerByte, "all bytes must be copied");
__ sub_32(count, count, bytes_to_write/bytes_per_count);
return bytes_to_write / bytes_per_count;
}
// Copies 'count' of elements using shifted copy loop
//
// Arguments:
// from: beginning (if forward) or upper bound (if !forward) of the region to be read
// to: beginning (if forward) or upper bound (if !forward) of the region to be written
// count: 32-bit int, number of elements to be copied
// to_remainder: remainder of dividing 'to' by wordSize
// bytes_per_count: size of an element
// forward: specifies copy direction
// Rval: contains an already read but not yet written word
//
//
// Notes:
// 'count' must not be less then the returned value
// 'from' must be aligned by wordSize
// 'to' must be aligned by bytes_per_count but must not be aligned by wordSize
// shifts 'to' by the number of copied bytes
//
// Scratches R3-R10, R12
int align_dst_and_generate_shifted_copy_loop(Register from, Register to, Register count, Register Rval,
int to_remainder, int bytes_per_count, bool forward) {
assert (0 < to_remainder && to_remainder < wordSize, "to_remainder is invalid");
const Register tmp = forward ? R3 : R12;
assert_different_registers(from, to, count, Rval, tmp);
int required_to_align = align_dst(to, count, Rval, tmp, to_remainder, bytes_per_count, forward);
int lsr_shift = (wordSize - to_remainder) * BitsPerByte;
int lsl_shift = to_remainder * BitsPerByte;
int min_copy;
if (forward) {
min_copy = generate_forward_shifted_copy_loop(from, to, count, bytes_per_count, lsr_shift, lsl_shift);
} else {
min_copy = generate_backward_shifted_copy_loop(from, to, count, bytes_per_count, lsr_shift, lsl_shift);
}
return min_copy + required_to_align;
}
// Copies 'count' of elements using shifted copy loop
//
// Arguments:
// from: beginning (if forward) or upper bound (if !forward) of the region to be read
// to: beginning (if forward) or upper bound (if !forward) of the region to be written
// count: 32-bit int, number of elements to be copied
// bytes_per_count: size of an element
// forward: specifies copy direction
//
// Notes:
// 'count' must not be less then the returned value
// 'from' must be aligned by wordSize
// 'to' must be aligned by bytes_per_count but must not be aligned by wordSize
// shifts 'to' by the number of copied bytes
//
// Scratches 'from', 'count', R3 and R12.
// R4-R10 saved for use.
int align_dst_and_generate_shifted_copy_loop(Register from, Register to, Register count, int bytes_per_count, bool forward, bool unsafe_copy = false) {
const Register Rval = forward ? R12 : R3; // as generate_{forward,backward}_shifted_copy_loop expect
int min_copy = 0;
// Note: if {seq} is a sequence of numbers, L{seq} means that if the execution reaches this point,
// then the remainder of 'to' divided by wordSize is one of elements of {seq}.
__ push(RegisterSet(R4,R10));
{
// UnsafeCopyMemory page error: continue after ucm
UnsafeCopyMemoryMark ucmm(this, unsafe_copy, true);
load_one(Rval, from, wordSize, forward);
switch (bytes_per_count) {
case 2:
min_copy = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 2, bytes_per_count, forward);
break;
case 1:
{
Label L1, L2, L3;
int min_copy1, min_copy2, min_copy3;
Label L_loop_finished;
if (forward) {
__ tbz(to, 0, L2);
__ tbz(to, 1, L1);
__ BIND(L3);
min_copy3 = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 3, bytes_per_count, forward);
__ b(L_loop_finished);
__ BIND(L1);
min_copy1 = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 1, bytes_per_count, forward);
__ b(L_loop_finished);
__ BIND(L2);
min_copy2 = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 2, bytes_per_count, forward);
} else {
__ tbz(to, 0, L2);
__ tbnz(to, 1, L3);
__ BIND(L1);
min_copy1 = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 1, bytes_per_count, forward);
__ b(L_loop_finished);
__ BIND(L3);
min_copy3 = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 3, bytes_per_count, forward);
__ b(L_loop_finished);
__ BIND(L2);
min_copy2 = align_dst_and_generate_shifted_copy_loop(from, to, count, Rval, 2, bytes_per_count, forward);
}
min_copy = MAX2(MAX2(min_copy1, min_copy2), min_copy3);
__ BIND(L_loop_finished);
break;
}
default:
ShouldNotReachHere();
break;
}
}
__ pop(RegisterSet(R4,R10));
return min_copy;
}
#ifndef PRODUCT
int * get_arraycopy_counter(int bytes_per_count) {
switch (bytes_per_count) {
case 1:
return &SharedRuntime::_jbyte_array_copy_ctr;
case 2:
return &SharedRuntime::_jshort_array_copy_ctr;
case 4:
return &SharedRuntime::_jint_array_copy_ctr;
case 8:
return &SharedRuntime::_jlong_array_copy_ctr;
default:
ShouldNotReachHere();
return NULL;
}
}
#endif // !PRODUCT
address generate_unsafecopy_common_error_exit() {
address start_pc = __ pc();
__ mov(R0, 0);
__ ret();
return start_pc;
}
//
// Generate stub for primitive array copy. If "aligned" is true, the
// "from" and "to" addresses are assumed to be heapword aligned.
//
// If "disjoint" is true, arrays are assumed to be disjoint, otherwise they may overlap and
// "nooverlap_target" must be specified as the address to jump if they don't.
//
// Arguments for generated stub:
// from: R0
// to: R1
// count: R2 treated as signed 32-bit int
//
address generate_primitive_copy(bool aligned, const char * name, bool status, int bytes_per_count, bool disjoint, address nooverlap_target = NULL) {
__ align(CodeEntryAlignment);
StubCodeMark mark(this, "StubRoutines", name);
address start = __ pc();
const Register from = R0; // source array address
const Register to = R1; // destination array address
const Register count = R2; // elements count
const Register tmp1 = R3;
const Register tmp2 = R12;
if (!aligned) {
BLOCK_COMMENT("Entry:");
}
__ zap_high_non_significant_bits(R2);
if (!disjoint) {
assert (nooverlap_target != NULL, "must be specified for conjoint case");
array_overlap_test(nooverlap_target, exact_log2(bytes_per_count), tmp1, tmp2);
}
inc_counter_np(*get_arraycopy_counter(bytes_per_count), tmp1, tmp2);
// Conjoint case: since execution reaches this point, the arrays overlap, so performing backward copy
// Disjoint case: perform forward copy
bool forward = disjoint;
if (!forward) {
// Set 'from' and 'to' to upper bounds
int log_bytes_per_count = exact_log2(bytes_per_count);
__ add_ptr_scaled_int32(to, to, count, log_bytes_per_count);
__ add_ptr_scaled_int32(from, from, count, log_bytes_per_count);
}
// There are two main copy loop implementations:
// *) The huge and complex one applicable only for large enough arrays
// *) The small and simple one applicable for any array (but not efficient for large arrays).
// Currently "small" implementation is used if and only if the "large" one could not be used.
// XXX optim: tune the limit higher ?
// Large implementation lower applicability bound is actually determined by
// aligned copy loop which require <=7 bytes for src alignment, and 8 words for aligned copy loop.
const int small_copy_limit = (8*wordSize + 7) / bytes_per_count;
Label L_small_array;
__ cmp_32(count, small_copy_limit);
__ b(L_small_array, le);
// Otherwise proceed with large implementation.
bool from_is_aligned = (bytes_per_count >= 8);
if (aligned && forward && (HeapWordSize % 8 == 0)) {
// if 'from' is heapword aligned and HeapWordSize is divisible by 8,
// then from is aligned by 8
from_is_aligned = true;
}
int count_required_to_align = 0;
{
// UnsafeCopyMemoryMark page error: continue at UnsafeCopyMemory common_error_exit
UnsafeCopyMemoryMark ucmm(this, !aligned, false);
count_required_to_align = from_is_aligned ? 0 : align_src(from, to, count, tmp1, bytes_per_count, forward);
assert (small_copy_limit >= count_required_to_align, "alignment could exhaust count");
}
// now 'from' is aligned
bool to_is_aligned = false;
if (bytes_per_count >= wordSize) {
// 'to' is aligned by bytes_per_count, so it is aligned by wordSize
to_is_aligned = true;
} else {
if (aligned && (8 % HeapWordSize == 0) && (HeapWordSize % wordSize == 0)) {
// Originally 'from' and 'to' were heapword aligned;
// (from - to) has not been changed, so since now 'from' is 8-byte aligned, then it is also heapword aligned,
// so 'to' is also heapword aligned and thus aligned by wordSize.
to_is_aligned = true;
}
}
Label L_unaligned_dst;
if (!to_is_aligned) {
BLOCK_COMMENT("Check dst alignment:");
__ tst(to, wordSize - 1);
__ b(L_unaligned_dst, ne); // 'to' is not aligned
}
// 'from' and 'to' are properly aligned
int min_copy;
if (forward) {
min_copy = generate_forward_aligned_copy_loop(from, to, count, bytes_per_count, !aligned /*add UnsafeCopyMemory entry*/);
} else {
min_copy = generate_backward_aligned_copy_loop(from, to, count, bytes_per_count, !aligned /*add UnsafeCopyMemory entry*/);
}
assert(small_copy_limit >= count_required_to_align + min_copy, "first loop might exhaust count");
if (status) {
__ mov(R0, 0); // OK
}
__ ret();
{
copy_small_array(from, to, count, tmp1, tmp2, bytes_per_count, forward, L_small_array /* entry */, !aligned /*add UnsafeCopyMemory entry*/);
if (status) {
__ mov(R0, 0); // OK
}
__ ret();
}
if (! to_is_aligned) {
__ BIND(L_unaligned_dst);
int min_copy_shifted = align_dst_and_generate_shifted_copy_loop(from, to, count, bytes_per_count, forward, !aligned /*add UnsafeCopyMemory entry*/);
assert (small_copy_limit >= count_required_to_align + min_copy_shifted, "first loop might exhaust count");
if (status) {
__ mov(R0, 0); // OK
}
__ ret();
}
return start;
}
// Generates pattern of code to be placed after raw data copying in generate_oop_copy
// Includes return from arraycopy stub.
//
// Arguments:
// to: destination pointer after copying.
// if 'forward' then 'to' == upper bound, else 'to' == beginning of the modified region
// count: total number of copied elements, 32-bit int
//
// Blows all volatile R0-R3, Rtemp, LR) and 'to', 'count', 'tmp' registers.
void oop_arraycopy_stub_epilogue_helper(Register to, Register count, Register tmp, bool status, bool forward, DecoratorSet decorators) {
assert_different_registers(to, count, tmp);
if (forward) {
// 'to' is upper bound of the modified region
// restore initial dst:
__ sub_ptr_scaled_int32(to, to, count, LogBytesPerHeapOop);
}
// 'to' is the beginning of the region
BarrierSetAssembler *bs = BarrierSet::barrier_set()->barrier_set_assembler();
bs->arraycopy_epilogue(_masm, decorators, true, to, count, tmp);
if (status) {
__ mov(R0, 0); // OK
}
__ pop(PC);
}
// Generate stub for assign-compatible oop copy. If "aligned" is true, the
// "from" and "to" addresses are assumed to be heapword aligned.
//
// If "disjoint" is true, arrays are assumed to be disjoint, otherwise they may overlap and
// "nooverlap_target" must be specified as the address to jump if they don't.
//
// Arguments for generated stub:
// from: R0
// to: R1
// count: R2 treated as signed 32-bit int
//
address generate_oop_copy(bool aligned, const char * name, bool status, bool disjoint, address nooverlap_target = NULL) {
__ align(CodeEntryAlignment);
StubCodeMark mark(this, "StubRoutines", name);
address start = __ pc();
Register from = R0;
Register to = R1;
Register count = R2;
Register tmp1 = R3;
Register tmp2 = R12;
if (!aligned) {
BLOCK_COMMENT("Entry:");
}
__ zap_high_non_significant_bits(R2);
if (!disjoint) {
assert (nooverlap_target != NULL, "must be specified for conjoint case");
array_overlap_test(nooverlap_target, LogBytesPerHeapOop, tmp1, tmp2);
}
inc_counter_np(SharedRuntime::_oop_array_copy_ctr, tmp1, tmp2);
// Conjoint case: since execution reaches this point, the arrays overlap, so performing backward copy
// Disjoint case: perform forward copy
bool forward = disjoint;
const int bytes_per_count = BytesPerHeapOop;
const int log_bytes_per_count = LogBytesPerHeapOop;
const Register saved_count = LR;
const int callee_saved_regs = 3; // R0-R2
// LR is used later to save barrier args
__ push(LR);
DecoratorSet decorators = IN_HEAP | IS_ARRAY;
if (disjoint) {
decorators |= ARRAYCOPY_DISJOINT;
}
if (aligned) {
decorators |= ARRAYCOPY_ALIGNED;
}
BarrierSetAssembler *bs = BarrierSet::barrier_set()->barrier_set_assembler();
bs->arraycopy_prologue(_masm, decorators, true, to, count, callee_saved_regs);
// save arguments for barrier generation (after the pre barrier)
__ mov(saved_count, count);
if (!forward) {
__ add_ptr_scaled_int32(to, to, count, log_bytes_per_count);
__ add_ptr_scaled_int32(from, from, count, log_bytes_per_count);
}
// for short arrays, just do single element copy
Label L_small_array;
const int small_copy_limit = (8*wordSize + 7)/bytes_per_count; // XXX optim: tune the limit higher ?
__ cmp_32(count, small_copy_limit);
__ b(L_small_array, le);
bool from_is_aligned = (bytes_per_count >= 8);
if (aligned && forward && (HeapWordSize % 8 == 0)) {
// if 'from' is heapword aligned and HeapWordSize is divisible by 8,
// then from is aligned by 8
from_is_aligned = true;
}
int count_required_to_align = from_is_aligned ? 0 : align_src(from, to, count, tmp1, bytes_per_count, forward);
assert (small_copy_limit >= count_required_to_align, "alignment could exhaust count");
// now 'from' is aligned
bool to_is_aligned = false;
if (bytes_per_count >= wordSize) {
// 'to' is aligned by bytes_per_count, so it is aligned by wordSize
to_is_aligned = true;
} else {
if (aligned && (8 % HeapWordSize == 0) && (HeapWordSize % wordSize == 0)) {
// Originally 'from' and 'to' were heapword aligned;
// (from - to) has not been changed, so since now 'from' is 8-byte aligned, then it is also heapword aligned,
// so 'to' is also heapword aligned and thus aligned by wordSize.
to_is_aligned = true;
}
}
Label L_unaligned_dst;
if (!to_is_aligned) {
BLOCK_COMMENT("Check dst alignment:");
__ tst(to, wordSize - 1);
__ b(L_unaligned_dst, ne); // 'to' is not aligned
}
int min_copy;
if (forward) {
min_copy = generate_forward_aligned_copy_loop(from, to, count, bytes_per_count);
} else {
min_copy = generate_backward_aligned_copy_loop(from, to, count, bytes_per_count);
}
assert(small_copy_limit >= count_required_to_align + min_copy, "first loop might exhaust count");
oop_arraycopy_stub_epilogue_helper(to, saved_count, /* tmp */ tmp1, status, forward, decorators);
{
copy_small_array(from, to, count, tmp1, noreg, bytes_per_count, forward, L_small_array);
oop_arraycopy_stub_epilogue_helper(to, saved_count, /* tmp */ tmp1, status, forward, decorators);
}
if (!to_is_aligned) {
__ BIND(L_unaligned_dst);
ShouldNotReachHere();
int min_copy_shifted = align_dst_and_generate_shifted_copy_loop(from, to, count, bytes_per_count, forward);
assert (small_copy_limit >= count_required_to_align + min_copy_shifted, "first loop might exhaust count");
oop_arraycopy_stub_epilogue_helper(to, saved_count, /* tmp */ tmp1, status, forward, decorators);
}
return start;
}
// Generate 'unsafe' array copy stub
// Though just as safe as the other stubs, it takes an unscaled
// size_t argument instead of an element count.
//
// Arguments for generated stub:
// from: R0
// to: R1
// count: R2 byte count, treated as ssize_t, can be zero
//
// Examines the alignment of the operands and dispatches
// to a long, int, short, or byte copy loop.
//
address generate_unsafe_copy(const char* name) {
const Register R0_from = R0; // source array address
const Register R1_to = R1; // destination array address
const Register R2_count = R2; // elements count
const Register R3_bits = R3; // test copy of low bits
__ align(CodeEntryAlignment);
StubCodeMark mark(this, "StubRoutines", name);
address start = __ pc();
const Register tmp = Rtemp;
// bump this on entry, not on exit:
inc_counter_np(SharedRuntime::_unsafe_array_copy_ctr, R3, tmp);
__ orr(R3_bits, R0_from, R1_to);
__ orr(R3_bits, R2_count, R3_bits);
__ tst(R3_bits, BytesPerLong-1);
__ mov(R2_count,AsmOperand(R2_count,asr,LogBytesPerLong), eq);
__ jump(StubRoutines::_jlong_arraycopy, relocInfo::runtime_call_type, tmp, eq);
__ tst(R3_bits, BytesPerInt-1);
__ mov(R2_count,AsmOperand(R2_count,asr,LogBytesPerInt), eq);
__ jump(StubRoutines::_jint_arraycopy, relocInfo::runtime_call_type, tmp, eq);
__ tst(R3_bits, BytesPerShort-1);
__ mov(R2_count,AsmOperand(R2_count,asr,LogBytesPerShort), eq);
__ jump(StubRoutines::_jshort_arraycopy, relocInfo::runtime_call_type, tmp, eq);
__ jump(StubRoutines::_jbyte_arraycopy, relocInfo::runtime_call_type, tmp);
return start;
}
// Helper for generating a dynamic type check.
// Smashes only the given temp registers.
void generate_type_check(Register sub_klass,
Register super_check_offset,
Register super_klass,
Register tmp1,
Register tmp2,
Register tmp3,
Label& L_success) {
assert_different_registers(sub_klass, super_check_offset, super_klass, tmp1, tmp2, tmp3);
BLOCK_COMMENT("type_check:");
// If the pointers are equal, we are done (e.g., String[] elements).
__ cmp(super_klass, sub_klass);
__ b(L_success, eq); // fast success
Label L_loop, L_fail;
int sc_offset = in_bytes(Klass::secondary_super_cache_offset());
// Check the supertype display:
__ ldr(tmp1, Address(sub_klass, super_check_offset));
__ cmp(tmp1, super_klass);
__ b(L_success, eq);
__ cmp(super_check_offset, sc_offset);
__ b(L_fail, ne); // failure
BLOCK_COMMENT("type_check_slow_path:");
// a couple of useful fields in sub_klass:
int ss_offset = in_bytes(Klass::secondary_supers_offset());
// Do a linear scan of the secondary super-klass chain.
#ifndef PRODUCT
int* pst_counter = &SharedRuntime::_partial_subtype_ctr;
__ inc_counter((address) pst_counter, tmp1, tmp2);
#endif
Register scan_temp = tmp1;
Register count_temp = tmp2;
// We will consult the secondary-super array.
__ ldr(scan_temp, Address(sub_klass, ss_offset));
Register search_key = super_klass;
// Load the array length.
__ ldr_s32(count_temp, Address(scan_temp, Array<Klass*>::length_offset_in_bytes()));
__ add(scan_temp, scan_temp, Array<Klass*>::base_offset_in_bytes());
__ add(count_temp, count_temp, 1);
// Top of search loop
__ bind(L_loop);
// Notes:
// scan_temp starts at the array elements
// count_temp is 1+size
__ subs(count_temp, count_temp, 1);
__ b(L_fail, eq); // not found
// Load next super to check
// In the array of super classes elements are pointer sized.
int element_size = wordSize;
__ ldr(tmp3, Address(scan_temp, element_size, post_indexed));
// Look for Rsuper_klass on Rsub_klass's secondary super-class-overflow list
__ cmp(tmp3, search_key);
// A miss means we are NOT a subtype and need to keep looping
__ b(L_loop, ne);
// Falling out the bottom means we found a hit; we ARE a subtype
// Success. Cache the super we found and proceed in triumph.
__ str(super_klass, Address(sub_klass, sc_offset));
// Jump to success
__ b(L_success);
// Fall through on failure!
__ bind(L_fail);
}
// Generate stub for checked oop copy.
//
// Arguments for generated stub:
// from: R0
// to: R1
// count: R2 treated as signed 32-bit int
// ckoff: R3 (super_check_offset)
// ckval: R4 (super_klass)
// ret: R0 zero for success; (-1^K) where K is partial transfer count (32-bit)
//
address generate_checkcast_copy(const char * name) {
__ align(CodeEntryAlignment);
StubCodeMark mark(this, "StubRoutines", name);
address start = __ pc();
const Register from = R0; // source array address
const Register to = R1; // destination array address
const Register count = R2; // elements count
const Register R3_ckoff = R3; // super_check_offset
const Register R4_ckval = R4; // super_klass
const int callee_saved_regs = 4; // LR saved differently
Label load_element, store_element, do_epilogue, fail;
BLOCK_COMMENT("Entry:");
__ zap_high_non_significant_bits(R2);
int pushed = 0;
__ push(LR);
pushed+=1;
DecoratorSet decorators = IN_HEAP | IS_ARRAY | ARRAYCOPY_CHECKCAST;
BarrierSetAssembler *bs = BarrierSet::barrier_set()->barrier_set_assembler();
bs->arraycopy_prologue(_masm, decorators, true, to, count, callee_saved_regs);
const RegisterSet caller_saved_regs = RegisterSet(R4,R6) | RegisterSet(R8,R9) | altFP_7_11;
__ push(caller_saved_regs);
assert(caller_saved_regs.size() == 6, "check the count");
pushed+=6;
__ ldr(R4_ckval,Address(SP, wordSize*pushed)); // read the argument that was on the stack
// Save arguments for barrier generation (after the pre barrier):
// - must be a caller saved register and not LR
// - ARM32: avoid R10 in case RThread is needed
const Register saved_count = altFP_7_11;
__ movs(saved_count, count); // and test count
__ b(load_element,ne);
// nothing to copy
__ mov(R0, 0);
__ pop(caller_saved_regs);
__ pop(PC);
// ======== begin loop ========
// (Loop is rotated; its entry is load_element.)
__ align(OptoLoopAlignment);
__ BIND(store_element);
if (UseCompressedOops) {
__ store_heap_oop(Address(to, BytesPerHeapOop, post_indexed), R5); // store the oop, changes flags
__ subs_32(count,count,1);
} else {
__ subs_32(count,count,1);
__ str(R5, Address(to, BytesPerHeapOop, post_indexed)); // store the oop
}
__ b(do_epilogue, eq); // count exhausted
// ======== loop entry is here ========
__ BIND(load_element);
__ load_heap_oop(R5, Address(from, BytesPerHeapOop, post_indexed)); // load the oop
__ cbz(R5, store_element); // NULL
__ load_klass(R6, R5);
generate_type_check(R6, R3_ckoff, R4_ckval, /*tmps*/ R12, R8, R9,
// branch to this on success:
store_element);
// ======== end loop ========
// It was a real error; we must depend on the caller to finish the job.
// Register count has number of *remaining* oops, saved_count number of *total* oops.
// Emit GC store barriers for the oops we have copied
// and report their number to the caller (0 or (-1^n))
__ BIND(fail);
// Note: fail marked by the fact that count differs from saved_count
__ BIND(do_epilogue);
Register copied = R4; // saved
Label L_not_copied;
__ subs_32(copied, saved_count, count); // copied count (in saved reg)
__ b(L_not_copied, eq); // nothing was copied, skip post barrier
__ sub(to, to, AsmOperand(copied, lsl, LogBytesPerHeapOop)); // initial to value
__ mov(R12, copied); // count arg scratched by post barrier
bs->arraycopy_epilogue(_masm, decorators, true, to, R12, R3);
assert_different_registers(R3,R12,LR,copied,saved_count);
inc_counter_np(SharedRuntime::_checkcast_array_copy_ctr, R3, R12);
__ BIND(L_not_copied);
__ cmp_32(copied, saved_count); // values preserved in saved registers
__ mov(R0, 0, eq); // 0 if all copied
__ mvn(R0, copied, ne); // else NOT(copied)
__ pop(caller_saved_regs);
__ pop(PC);
return start;
}
// Perform range checks on the proposed arraycopy.
// Kills the two temps, but nothing else.
void arraycopy_range_checks(Register src, // source array oop
Register src_pos, // source position (32-bit int)
Register dst, // destination array oop
Register dst_pos, // destination position (32-bit int)
Register length, // length of copy (32-bit int)
Register temp1, Register temp2,
Label& L_failed) {
BLOCK_COMMENT("arraycopy_range_checks:");
// if (src_pos + length > arrayOop(src)->length() ) FAIL;
const Register array_length = temp1; // scratch
const Register end_pos = temp2; // scratch
__ add_32(end_pos, length, src_pos); // src_pos + length
__ ldr_s32(array_length, Address(src, arrayOopDesc::length_offset_in_bytes()));
__ cmp_32(end_pos, array_length);
__ b(L_failed, hi);
// if (dst_pos + length > arrayOop(dst)->length() ) FAIL;
__ add_32(end_pos, length, dst_pos); // dst_pos + length
__ ldr_s32(array_length, Address(dst, arrayOopDesc::length_offset_in_bytes()));
__ cmp_32(end_pos, array_length);
__ b(L_failed, hi);
BLOCK_COMMENT("arraycopy_range_checks done");
}
//
// Generate generic array copy stubs
//
// Input:
// R0 - src oop
// R1 - src_pos (32-bit int)
// R2 - dst oop
// R3 - dst_pos (32-bit int)
// SP[0] - element count (32-bit int)
//
// Output: (32-bit int)
// R0 == 0 - success
// R0 < 0 - need to call System.arraycopy
//
address generate_generic_copy(const char *name) {
Label L_failed, L_objArray;
// Input registers
const Register src = R0; // source array oop
const Register src_pos = R1; // source position
const Register dst = R2; // destination array oop
const Register dst_pos = R3; // destination position
// registers used as temp
const Register R5_src_klass = R5; // source array klass
const Register R6_dst_klass = R6; // destination array klass
const Register R_lh = altFP_7_11; // layout handler
const Register R8_temp = R8;
__ align(CodeEntryAlignment);
StubCodeMark mark(this, "StubRoutines", name);
address start = __ pc();
__ zap_high_non_significant_bits(R1);
__ zap_high_non_significant_bits(R3);
__ zap_high_non_significant_bits(R4);
int pushed = 0;
const RegisterSet saved_regs = RegisterSet(R4,R6) | RegisterSet(R8,R9) | altFP_7_11;
__ push(saved_regs);
assert(saved_regs.size() == 6, "check the count");
pushed+=6;
// bump this on entry, not on exit:
inc_counter_np(SharedRuntime::_generic_array_copy_ctr, R5, R12);
const Register length = R4; // elements count
__ ldr(length, Address(SP,4*pushed));
//-----------------------------------------------------------------------
// Assembler stubs will be used for this call to arraycopy
// if the following conditions are met:
//
// (1) src and dst must not be null.
// (2) src_pos must not be negative.
// (3) dst_pos must not be negative.
// (4) length must not be negative.
// (5) src klass and dst klass should be the same and not NULL.
// (6) src and dst should be arrays.
// (7) src_pos + length must not exceed length of src.
// (8) dst_pos + length must not exceed length of dst.
BLOCK_COMMENT("arraycopy initial argument checks");
// if (src == NULL) return -1;
__ cbz(src, L_failed);
// if (src_pos < 0) return -1;
__ cmp_32(src_pos, 0);
__ b(L_failed, lt);
// if (dst == NULL) return -1;
__ cbz(dst, L_failed);
// if (dst_pos < 0) return -1;
__ cmp_32(dst_pos, 0);
__ b(L_failed, lt);
// if (length < 0) return -1;
__ cmp_32(length, 0);
__ b(L_failed, lt);
BLOCK_COMMENT("arraycopy argument klass checks");
// get src->klass()
__ load_klass(R5_src_klass, src);
// Load layout helper
//
// |array_tag| | header_size | element_type | |log2_element_size|
// 32 30 24 16 8 2 0
//
// array_tag: typeArray = 0x3, objArray = 0x2, non-array = 0x0
//
int lh_offset = in_bytes(Klass::layout_helper_offset());
__ ldr_u32(R_lh, Address(R5_src_klass, lh_offset));
__ load_klass(R6_dst_klass, dst);
// Handle objArrays completely differently...
juint objArray_lh = Klass::array_layout_helper(T_OBJECT);
__ mov_slow(R8_temp, objArray_lh);
__ cmp_32(R_lh, R8_temp);
__ b(L_objArray,eq);
// if (src->klass() != dst->klass()) return -1;
__ cmp(R5_src_klass, R6_dst_klass);
__ b(L_failed, ne);
// if (!src->is_Array()) return -1;
__ cmp_32(R_lh, Klass::_lh_neutral_value); // < 0
__ b(L_failed, ge);
arraycopy_range_checks(src, src_pos, dst, dst_pos, length,
R8_temp, R6_dst_klass, L_failed);
{
// TypeArrayKlass
//
// src_addr = (src + array_header_in_bytes()) + (src_pos << log2elemsize);
// dst_addr = (dst + array_header_in_bytes()) + (dst_pos << log2elemsize);
//
const Register R6_offset = R6_dst_klass; // array offset
const Register R12_elsize = R12; // log2 element size
__ logical_shift_right(R6_offset, R_lh, Klass::_lh_header_size_shift);
__ andr(R6_offset, R6_offset, (unsigned int)Klass::_lh_header_size_mask); // array_offset
__ add(src, src, R6_offset); // src array offset
__ add(dst, dst, R6_offset); // dst array offset
__ andr(R12_elsize, R_lh, (unsigned int)Klass::_lh_log2_element_size_mask); // log2 element size
// next registers should be set before the jump to corresponding stub
const Register from = R0; // source array address
const Register to = R1; // destination array address
const Register count = R2; // elements count
// 'from', 'to', 'count' registers should be set in this order
// since they are the same as 'src', 'src_pos', 'dst'.
BLOCK_COMMENT("scale indexes to element size");
__ add(from, src, AsmOperand(src_pos, lsl, R12_elsize)); // src_addr
__ add(to, dst, AsmOperand(dst_pos, lsl, R12_elsize)); // dst_addr
__ mov(count, length); // length
// XXX optim: avoid later push in arraycopy variants ?
__ pop(saved_regs);
BLOCK_COMMENT("choose copy loop based on element size");
__ cmp(R12_elsize, 0);
__ b(StubRoutines::_jbyte_arraycopy,eq);
__ cmp(R12_elsize, LogBytesPerShort);
__ b(StubRoutines::_jshort_arraycopy,eq);
__ cmp(R12_elsize, LogBytesPerInt);
__ b(StubRoutines::_jint_arraycopy,eq);
__ b(StubRoutines::_jlong_arraycopy);
}
// ObjArrayKlass
__ BIND(L_objArray);
// live at this point: R5_src_klass, R6_dst_klass, src[_pos], dst[_pos], length
Label L_plain_copy, L_checkcast_copy;
// test array classes for subtyping
__ cmp(R5_src_klass, R6_dst_klass); // usual case is exact equality
__ b(L_checkcast_copy, ne);
BLOCK_COMMENT("Identically typed arrays");
{
// Identically typed arrays can be copied without element-wise checks.
arraycopy_range_checks(src, src_pos, dst, dst_pos, length,
R8_temp, R_lh, L_failed);
// next registers should be set before the jump to corresponding stub
const Register from = R0; // source array address
const Register to = R1; // destination array address
const Register count = R2; // elements count
__ add(src, src, arrayOopDesc::base_offset_in_bytes(T_OBJECT)); //src offset
__ add(dst, dst, arrayOopDesc::base_offset_in_bytes(T_OBJECT)); //dst offset
__ add_ptr_scaled_int32(from, src, src_pos, LogBytesPerHeapOop); // src_addr
__ add_ptr_scaled_int32(to, dst, dst_pos, LogBytesPerHeapOop); // dst_addr
__ BIND(L_plain_copy);
__ mov(count, length);
__ pop(saved_regs); // XXX optim: avoid later push in oop_arraycopy ?
__ b(StubRoutines::_oop_arraycopy);
}
{
__ BIND(L_checkcast_copy);
// live at this point: R5_src_klass, R6_dst_klass
// Before looking at dst.length, make sure dst is also an objArray.
__ ldr_u32(R8_temp, Address(R6_dst_klass, lh_offset));
__ cmp_32(R_lh, R8_temp);
__ b(L_failed, ne);
// It is safe to examine both src.length and dst.length.
arraycopy_range_checks(src, src_pos, dst, dst_pos, length,
R8_temp, R_lh, L_failed);
// next registers should be set before the jump to corresponding stub
const Register from = R0; // source array address
const Register to = R1; // destination array address
const Register count = R2; // elements count
// Marshal the base address arguments now, freeing registers.
__ add(src, src, arrayOopDesc::base_offset_in_bytes(T_OBJECT)); //src offset
__ add(dst, dst, arrayOopDesc::base_offset_in_bytes(T_OBJECT)); //dst offset
__ add_ptr_scaled_int32(from, src, src_pos, LogBytesPerHeapOop); // src_addr
__ add_ptr_scaled_int32(to, dst, dst_pos, LogBytesPerHeapOop); // dst_addr
__ mov(count, length); // length (reloaded)
Register sco_temp = R3; // this register is free now
assert_different_registers(from, to, count, sco_temp,
R6_dst_klass, R5_src_klass);
// Generate the type check.
int sco_offset = in_bytes(Klass::super_check_offset_offset());
__ ldr_u32(sco_temp, Address(R6_dst_klass, sco_offset));
generate_type_check(R5_src_klass, sco_temp, R6_dst_klass,
R8_temp, R9,
R12,
L_plain_copy);
// Fetch destination element klass from the ObjArrayKlass header.
int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
// the checkcast_copy loop needs two extra arguments:
const Register Rdst_elem_klass = R3;
__ ldr(Rdst_elem_klass, Address(R6_dst_klass, ek_offset)); // dest elem klass
__ pop(saved_regs); // XXX optim: avoid later push in oop_arraycopy ?
__ str(Rdst_elem_klass, Address(SP,0)); // dest elem klass argument
__ ldr_u32(R3, Address(Rdst_elem_klass, sco_offset)); // sco of elem klass
__ b(StubRoutines::_checkcast_arraycopy);
}
__ BIND(L_failed);
__ pop(saved_regs);
__ mvn(R0, 0); // failure, with 0 copied
__ ret();
return start;
}
// Safefetch stubs.
void generate_safefetch(const char* name, int size, address* entry, address* fault_pc, address* continuation_pc) {
// safefetch signatures:
// int SafeFetch32(int* adr, int errValue);
// intptr_t SafeFetchN (intptr_t* adr, intptr_t errValue);
//
// arguments:
// R0 = adr
// R1 = errValue
//
// result:
// R0 = *adr or errValue
StubCodeMark mark(this, "StubRoutines", name);
// Entry point, pc or function descriptor.
*entry = __ pc();
// Load *adr into c_rarg2, may fault.
*fault_pc = __ pc();
switch (size) {
case 4: // int32_t
__ ldr_s32(R1, Address(R0));
break;
case 8: // int64_t
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