JDK14/Java14源码在线阅读
/*
* Copyright (c) 2012, 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
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*/
#include "precompiled.hpp"
#include "gc/shared/barrierSet.hpp"
#include "opto/arraycopynode.hpp"
#include "oops/objArrayKlass.hpp"
#include "opto/convertnode.hpp"
#include "opto/graphKit.hpp"
#include "opto/macro.hpp"
#include "opto/runtime.hpp"
#include "utilities/align.hpp"
void PhaseMacroExpand::insert_mem_bar(Node** ctrl, Node** mem, int opcode, Node* precedent) {
MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
mb->init_req(TypeFunc::Control, *ctrl);
mb->init_req(TypeFunc::Memory, *mem);
transform_later(mb);
*ctrl = new ProjNode(mb,TypeFunc::Control);
transform_later(*ctrl);
Node* mem_proj = new ProjNode(mb,TypeFunc::Memory);
transform_later(mem_proj);
*mem = mem_proj;
}
Node* PhaseMacroExpand::array_element_address(Node* ary, Node* idx, BasicType elembt) {
uint shift = exact_log2(type2aelembytes(elembt));
uint header = arrayOopDesc::base_offset_in_bytes(elembt);
Node* base = basic_plus_adr(ary, header);
#ifdef _LP64
// see comment in GraphKit::array_element_address
int index_max = max_jint - 1; // array size is max_jint, index is one less
const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
idx = transform_later( new ConvI2LNode(idx, lidxtype) );
#endif
Node* scale = new LShiftXNode(idx, intcon(shift));
transform_later(scale);
return basic_plus_adr(ary, base, scale);
}
Node* PhaseMacroExpand::ConvI2L(Node* offset) {
return transform_later(new ConvI2LNode(offset));
}
Node* PhaseMacroExpand::make_leaf_call(Node* ctrl, Node* mem,
const TypeFunc* call_type, address call_addr,
const char* call_name,
const TypePtr* adr_type,
Node* parm0, Node* parm1,
Node* parm2, Node* parm3,
Node* parm4, Node* parm5,
Node* parm6, Node* parm7) {
Node* call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
call->init_req(TypeFunc::Control, ctrl);
call->init_req(TypeFunc::I_O , top());
call->init_req(TypeFunc::Memory , mem);
call->init_req(TypeFunc::ReturnAdr, top());
call->init_req(TypeFunc::FramePtr, top());
// Hook each parm in order. Stop looking at the first NULL.
if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
/* close each nested if ===> */ } } } } } } } }
assert(call->in(call->req()-1) != NULL, "must initialize all parms");
return call;
}
//------------------------------generate_guard---------------------------
// Helper function for generating guarded fast-slow graph structures.
// The given 'test', if true, guards a slow path. If the test fails
// then a fast path can be taken. (We generally hope it fails.)
// In all cases, GraphKit::control() is updated to the fast path.
// The returned value represents the control for the slow path.
// The return value is never 'top'; it is either a valid control
// or NULL if it is obvious that the slow path can never be taken.
// Also, if region and the slow control are not NULL, the slow edge
// is appended to the region.
Node* PhaseMacroExpand::generate_guard(Node** ctrl, Node* test, RegionNode* region, float true_prob) {
if ((*ctrl)->is_top()) {
// Already short circuited.
return NULL;
}
// Build an if node and its projections.
// If test is true we take the slow path, which we assume is uncommon.
if (_igvn.type(test) == TypeInt::ZERO) {
// The slow branch is never taken. No need to build this guard.
return NULL;
}
IfNode* iff = new IfNode(*ctrl, test, true_prob, COUNT_UNKNOWN);
transform_later(iff);
Node* if_slow = new IfTrueNode(iff);
transform_later(if_slow);
if (region != NULL) {
region->add_req(if_slow);
}
Node* if_fast = new IfFalseNode(iff);
transform_later(if_fast);
*ctrl = if_fast;
return if_slow;
}
inline Node* PhaseMacroExpand::generate_slow_guard(Node** ctrl, Node* test, RegionNode* region) {
return generate_guard(ctrl, test, region, PROB_UNLIKELY_MAG(3));
}
void PhaseMacroExpand::generate_negative_guard(Node** ctrl, Node* index, RegionNode* region) {
if ((*ctrl)->is_top())
return; // already stopped
if (_igvn.type(index)->higher_equal(TypeInt::POS)) // [0,maxint]
return; // index is already adequately typed
Node* cmp_lt = new CmpINode(index, intcon(0));
transform_later(cmp_lt);
Node* bol_lt = new BoolNode(cmp_lt, BoolTest::lt);
transform_later(bol_lt);
generate_guard(ctrl, bol_lt, region, PROB_MIN);
}
void PhaseMacroExpand::generate_limit_guard(Node** ctrl, Node* offset, Node* subseq_length, Node* array_length, RegionNode* region) {
if ((*ctrl)->is_top())
return; // already stopped
bool zero_offset = _igvn.type(offset) == TypeInt::ZERO;
if (zero_offset && subseq_length->eqv_uncast(array_length))
return; // common case of whole-array copy
Node* last = subseq_length;
if (!zero_offset) { // last += offset
last = new AddINode(last, offset);
transform_later(last);
}
Node* cmp_lt = new CmpUNode(array_length, last);
transform_later(cmp_lt);
Node* bol_lt = new BoolNode(cmp_lt, BoolTest::lt);
transform_later(bol_lt);
generate_guard(ctrl, bol_lt, region, PROB_MIN);
}
Node* PhaseMacroExpand::generate_nonpositive_guard(Node** ctrl, Node* index, bool never_negative) {
if ((*ctrl)->is_top()) return NULL;
if (_igvn.type(index)->higher_equal(TypeInt::POS1)) // [1,maxint]
return NULL; // index is already adequately typed
Node* cmp_le = new CmpINode(index, intcon(0));
transform_later(cmp_le);
BoolTest::mask le_or_eq = (never_negative ? BoolTest::eq : BoolTest::le);
Node* bol_le = new BoolNode(cmp_le, le_or_eq);
transform_later(bol_le);
Node* is_notp = generate_guard(ctrl, bol_le, NULL, PROB_MIN);
return is_notp;
}
void PhaseMacroExpand::finish_arraycopy_call(Node* call, Node** ctrl, MergeMemNode** mem, const TypePtr* adr_type) {
transform_later(call);
*ctrl = new ProjNode(call,TypeFunc::Control);
transform_later(*ctrl);
Node* newmem = new ProjNode(call, TypeFunc::Memory);
transform_later(newmem);
uint alias_idx = C->get_alias_index(adr_type);
if (alias_idx != Compile::AliasIdxBot) {
*mem = MergeMemNode::make(*mem);
(*mem)->set_memory_at(alias_idx, newmem);
} else {
*mem = MergeMemNode::make(newmem);
}
transform_later(*mem);
}
address PhaseMacroExpand::basictype2arraycopy(BasicType t,
Node* src_offset,
Node* dest_offset,
bool disjoint_bases,
const char* &name,
bool dest_uninitialized) {
const TypeInt* src_offset_inttype = _igvn.find_int_type(src_offset);;
const TypeInt* dest_offset_inttype = _igvn.find_int_type(dest_offset);;
bool aligned = false;
bool disjoint = disjoint_bases;
// if the offsets are the same, we can treat the memory regions as
// disjoint, because either the memory regions are in different arrays,
// or they are identical (which we can treat as disjoint.) We can also
// treat a copy with a destination index less that the source index
// as disjoint since a low->high copy will work correctly in this case.
if (src_offset_inttype != NULL && src_offset_inttype->is_con() &&
dest_offset_inttype != NULL && dest_offset_inttype->is_con()) {
// both indices are constants
int s_offs = src_offset_inttype->get_con();
int d_offs = dest_offset_inttype->get_con();
int element_size = type2aelembytes(t);
aligned = ((arrayOopDesc::base_offset_in_bytes(t) + s_offs * element_size) % HeapWordSize == 0) &&
((arrayOopDesc::base_offset_in_bytes(t) + d_offs * element_size) % HeapWordSize == 0);
if (s_offs >= d_offs) disjoint = true;
} else if (src_offset == dest_offset && src_offset != NULL) {
// This can occur if the offsets are identical non-constants.
disjoint = true;
}
return StubRoutines::select_arraycopy_function(t, aligned, disjoint, name, dest_uninitialized);
}
#define XTOP LP64_ONLY(COMMA top())
// Generate an optimized call to arraycopy.
// Caller must guard against non-arrays.
// Caller must determine a common array basic-type for both arrays.
// Caller must validate offsets against array bounds.
// The slow_region has already collected guard failure paths
// (such as out of bounds length or non-conformable array types).
// The generated code has this shape, in general:
//
// if (length == 0) return // via zero_path
// slowval = -1
// if (types unknown) {
// slowval = call generic copy loop
// if (slowval == 0) return // via checked_path
// } else if (indexes in bounds) {
// if ((is object array) && !(array type check)) {
// slowval = call checked copy loop
// if (slowval == 0) return // via checked_path
// } else {
// call bulk copy loop
// return // via fast_path
// }
// }
// // adjust params for remaining work:
// if (slowval != -1) {
// n = -1^slowval; src_offset += n; dest_offset += n; length -= n
// }
// slow_region:
// call slow arraycopy(src, src_offset, dest, dest_offset, length)
// return // via slow_call_path
//
// This routine is used from several intrinsics: System.arraycopy,
// Object.clone (the array subcase), and Arrays.copyOf[Range].
//
Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode* alloc,
Node** ctrl, MergeMemNode* mem, Node** io,
const TypePtr* adr_type,
BasicType basic_elem_type,
Node* src, Node* src_offset,
Node* dest, Node* dest_offset,
Node* copy_length,
bool disjoint_bases,
bool length_never_negative,
RegionNode* slow_region) {
if (slow_region == NULL) {
slow_region = new RegionNode(1);
transform_later(slow_region);
}
Node* original_dest = dest;
bool dest_uninitialized = false;
// See if this is the initialization of a newly-allocated array.
// If so, we will take responsibility here for initializing it to zero.
// (Note: Because tightly_coupled_allocation performs checks on the
// out-edges of the dest, we need to avoid making derived pointers
// from it until we have checked its uses.)
if (ReduceBulkZeroing
&& !(UseTLAB && ZeroTLAB) // pointless if already zeroed
&& basic_elem_type != T_CONFLICT // avoid corner case
&& !src->eqv_uncast(dest)
&& alloc != NULL
&& _igvn.find_int_con(alloc->in(AllocateNode::ALength), 1) > 0
&& alloc->maybe_set_complete(&_igvn)) {
// "You break it, you buy it."
InitializeNode* init = alloc->initialization();
assert(init->is_complete(), "we just did this");
init->set_complete_with_arraycopy();
assert(dest->is_CheckCastPP(), "sanity");
assert(dest->in(0)->in(0) == init, "dest pinned");
adr_type = TypeRawPtr::BOTTOM; // all initializations are into raw memory
// From this point on, every exit path is responsible for
// initializing any non-copied parts of the object to zero.
// Also, if this flag is set we make sure that arraycopy interacts properly
// with G1, eliding pre-barriers. See CR 6627983.
dest_uninitialized = true;
} else {
// No zeroing elimination here.
alloc = NULL;
//original_dest = dest;
//dest_uninitialized = false;
}
uint alias_idx = C->get_alias_index(adr_type);
// Results are placed here:
enum { fast_path = 1, // normal void-returning assembly stub
checked_path = 2, // special assembly stub with cleanup
slow_call_path = 3, // something went wrong; call the VM
zero_path = 4, // bypass when length of copy is zero
bcopy_path = 5, // copy primitive array by 64-bit blocks
PATH_LIMIT = 6
};
RegionNode* result_region = new RegionNode(PATH_LIMIT);
PhiNode* result_i_o = new PhiNode(result_region, Type::ABIO);
PhiNode* result_memory = new PhiNode(result_region, Type::MEMORY, adr_type);
assert(adr_type != TypePtr::BOTTOM, "must be RawMem or a T[] slice");
transform_later(result_region);
transform_later(result_i_o);
transform_later(result_memory);
// The slow_control path:
Node* slow_control;
Node* slow_i_o = *io;
Node* slow_mem = mem->memory_at(alias_idx);
DEBUG_ONLY(slow_control = (Node*) badAddress);
// Checked control path:
Node* checked_control = top();
Node* checked_mem = NULL;
Node* checked_i_o = NULL;
Node* checked_value = NULL;
if (basic_elem_type == T_CONFLICT) {
assert(!dest_uninitialized, "");
Node* cv = generate_generic_arraycopy(ctrl, &mem,
adr_type,
src, src_offset, dest, dest_offset,
copy_length, dest_uninitialized);
if (cv == NULL) cv = intcon(-1); // failure (no stub available)
checked_control = *ctrl;
checked_i_o = *io;
checked_mem = mem->memory_at(alias_idx);
checked_value = cv;
*ctrl = top();
}
Node* not_pos = generate_nonpositive_guard(ctrl, copy_length, length_never_negative);
if (not_pos != NULL) {
Node* local_ctrl = not_pos, *local_io = *io;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
// (6) length must not be negative.
if (!length_never_negative) {
generate_negative_guard(&local_ctrl, copy_length, slow_region);
}
// copy_length is 0.
if (dest_uninitialized) {
assert(!local_ctrl->is_top(), "no ctrl?");
Node* dest_length = alloc->in(AllocateNode::ALength);
if (copy_length->eqv_uncast(dest_length)
|| _igvn.find_int_con(dest_length, 1) <= 0) {
// There is no zeroing to do. No need for a secondary raw memory barrier.
} else {
// Clear the whole thing since there are no source elements to copy.
generate_clear_array(local_ctrl, local_mem,
adr_type, dest, basic_elem_type,
intcon(0), NULL,
alloc->in(AllocateNode::AllocSize));
// Use a secondary InitializeNode as raw memory barrier.
// Currently it is needed only on this path since other
// paths have stub or runtime calls as raw memory barriers.
MemBarNode* mb = MemBarNode::make(C, Op_Initialize,
Compile::AliasIdxRaw,
top());
transform_later(mb);
mb->set_req(TypeFunc::Control,local_ctrl);
mb->set_req(TypeFunc::Memory, local_mem->memory_at(Compile::AliasIdxRaw));
local_ctrl = transform_later(new ProjNode(mb, TypeFunc::Control));
local_mem->set_memory_at(Compile::AliasIdxRaw, transform_later(new ProjNode(mb, TypeFunc::Memory)));
InitializeNode* init = mb->as_Initialize();
init->set_complete(&_igvn); // (there is no corresponding AllocateNode)
}
}
// Present the results of the fast call.
result_region->init_req(zero_path, local_ctrl);
result_i_o ->init_req(zero_path, local_io);
result_memory->init_req(zero_path, local_mem->memory_at(alias_idx));
}
if (!(*ctrl)->is_top() && dest_uninitialized) {
// We have to initialize the *uncopied* part of the array to zero.
// The copy destination is the slice dest[off..off+len]. The other slices
// are dest_head = dest[0..off] and dest_tail = dest[off+len..dest.length].
Node* dest_size = alloc->in(AllocateNode::AllocSize);
Node* dest_length = alloc->in(AllocateNode::ALength);
Node* dest_tail = transform_later( new AddINode(dest_offset, copy_length));
// If there is a head section that needs zeroing, do it now.
if (_igvn.find_int_con(dest_offset, -1) != 0) {
generate_clear_array(*ctrl, mem,
adr_type, dest, basic_elem_type,
intcon(0), dest_offset,
NULL);
}
// Next, perform a dynamic check on the tail length.
// It is often zero, and we can win big if we prove this.
// There are two wins: Avoid generating the ClearArray
// with its attendant messy index arithmetic, and upgrade
// the copy to a more hardware-friendly word size of 64 bits.
Node* tail_ctl = NULL;
if (!(*ctrl)->is_top() && !dest_tail->eqv_uncast(dest_length)) {
Node* cmp_lt = transform_later( new CmpINode(dest_tail, dest_length) );
Node* bol_lt = transform_later( new BoolNode(cmp_lt, BoolTest::lt) );
tail_ctl = generate_slow_guard(ctrl, bol_lt, NULL);
assert(tail_ctl != NULL || !(*ctrl)->is_top(), "must be an outcome");
}
// At this point, let's assume there is no tail.
if (!(*ctrl)->is_top() && alloc != NULL && basic_elem_type != T_OBJECT) {
// There is no tail. Try an upgrade to a 64-bit copy.
bool didit = false;
{
Node* local_ctrl = *ctrl, *local_io = *io;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
didit = generate_block_arraycopy(&local_ctrl, &local_mem, local_io,
adr_type, basic_elem_type, alloc,
src, src_offset, dest, dest_offset,
dest_size, dest_uninitialized);
if (didit) {
// Present the results of the block-copying fast call.
result_region->init_req(bcopy_path, local_ctrl);
result_i_o ->init_req(bcopy_path, local_io);
result_memory->init_req(bcopy_path, local_mem->memory_at(alias_idx));
}
}
if (didit) {
*ctrl = top(); // no regular fast path
}
}
// Clear the tail, if any.
if (tail_ctl != NULL) {
Node* notail_ctl = (*ctrl)->is_top() ? NULL : *ctrl;
*ctrl = tail_ctl;
if (notail_ctl == NULL) {
generate_clear_array(*ctrl, mem,
adr_type, dest, basic_elem_type,
dest_tail, NULL,
dest_size);
} else {
// Make a local merge.
Node* done_ctl = transform_later(new RegionNode(3));
Node* done_mem = transform_later(new PhiNode(done_ctl, Type::MEMORY, adr_type));
done_ctl->init_req(1, notail_ctl);
done_mem->init_req(1, mem->memory_at(alias_idx));
generate_clear_array(*ctrl, mem,
adr_type, dest, basic_elem_type,
dest_tail, NULL,
dest_size);
done_ctl->init_req(2, *ctrl);
done_mem->init_req(2, mem->memory_at(alias_idx));
*ctrl = done_ctl;
mem->set_memory_at(alias_idx, done_mem);
}
}
}
BasicType copy_type = basic_elem_type;
assert(basic_elem_type != T_ARRAY, "caller must fix this");
if (!(*ctrl)->is_top() && copy_type == T_OBJECT) {
// If src and dest have compatible element types, we can copy bits.
// Types S[] and D[] are compatible if D is a supertype of S.
//
// If they are not, we will use checked_oop_disjoint_arraycopy,
// which performs a fast optimistic per-oop check, and backs off
// further to JVM_ArrayCopy on the first per-oop check that fails.
// (Actually, we don't move raw bits only; the GC requires card marks.)
// We don't need a subtype check for validated copies and Object[].clone()
bool skip_subtype_check = ac->is_arraycopy_validated() || ac->is_copyof_validated() ||
ac->is_copyofrange_validated() || ac->is_clone_oop_array();
if (!skip_subtype_check) {
// Get the klass* for both src and dest
Node* src_klass = ac->in(ArrayCopyNode::SrcKlass);
Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
assert(src_klass != NULL && dest_klass != NULL, "should have klasses");
// Generate the subtype check.
// This might fold up statically, or then again it might not.
//
// Non-static example: Copying List<String>.elements to a new String[].
// The backing store for a List<String> is always an Object[],
// but its elements are always type String, if the generic types
// are correct at the source level.
//
// Test S[] against D[], not S against D, because (probably)
// the secondary supertype cache is less busy for S[] than S.
// This usually only matters when D is an interface.
Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, &_igvn);
// Plug failing path into checked_oop_disjoint_arraycopy
if (not_subtype_ctrl != top()) {
Node* local_ctrl = not_subtype_ctrl;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
// (At this point we can assume disjoint_bases, since types differ.)
int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
Node* p1 = basic_plus_adr(dest_klass, ek_offset);
Node* n1 = LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
Node* dest_elem_klass = transform_later(n1);
Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
adr_type,
dest_elem_klass,
src, src_offset, dest, dest_offset,
ConvI2X(copy_length), dest_uninitialized);
if (cv == NULL) cv = intcon(-1); // failure (no stub available)
checked_control = local_ctrl;
checked_i_o = *io;
checked_mem = local_mem->memory_at(alias_idx);
checked_value = cv;
}
}
// At this point we know we do not need type checks on oop stores.
BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
if (!bs->array_copy_requires_gc_barriers(alloc != NULL, copy_type, false, BarrierSetC2::Expansion)) {
// If we do not need gc barriers, copy using the jint or jlong stub.
copy_type = LP64_ONLY(UseCompressedOops ? T_INT : T_LONG) NOT_LP64(T_INT);
assert(type2aelembytes(basic_elem_type) == type2aelembytes(copy_type),
"sizes agree");
}
}
if (!(*ctrl)->is_top()) {
// Generate the fast path, if possible.
Node* local_ctrl = *ctrl;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
generate_unchecked_arraycopy(&local_ctrl, &local_mem,
adr_type, copy_type, disjoint_bases,
src, src_offset, dest, dest_offset,
ConvI2X(copy_length), dest_uninitialized);
// Present the results of the fast call.
result_region->init_req(fast_path, local_ctrl);
result_i_o ->init_req(fast_path, *io);
result_memory->init_req(fast_path, local_mem->memory_at(alias_idx));
}
// Here are all the slow paths up to this point, in one bundle:
assert(slow_region != NULL, "allocated on entry");
slow_control = slow_region;
DEBUG_ONLY(slow_region = (RegionNode*)badAddress);
*ctrl = checked_control;
if (!(*ctrl)->is_top()) {
// Clean up after the checked call.
// The returned value is either 0 or -1^K,
// where K = number of partially transferred array elements.
Node* cmp = new CmpINode(checked_value, intcon(0));
transform_later(cmp);
Node* bol = new BoolNode(cmp, BoolTest::eq);
transform_later(bol);
IfNode* iff = new IfNode(*ctrl, bol, PROB_MAX, COUNT_UNKNOWN);
transform_later(iff);
// If it is 0, we are done, so transfer to the end.
Node* checks_done = new IfTrueNode(iff);
transform_later(checks_done);
result_region->init_req(checked_path, checks_done);
result_i_o ->init_req(checked_path, checked_i_o);
result_memory->init_req(checked_path, checked_mem);
// If it is not zero, merge into the slow call.
*ctrl = new IfFalseNode(iff);
transform_later(*ctrl);
RegionNode* slow_reg2 = new RegionNode(3);
PhiNode* slow_i_o2 = new PhiNode(slow_reg2, Type::ABIO);
PhiNode* slow_mem2 = new PhiNode(slow_reg2, Type::MEMORY, adr_type);
transform_later(slow_reg2);
transform_later(slow_i_o2);
transform_later(slow_mem2);
slow_reg2 ->init_req(1, slow_control);
slow_i_o2 ->init_req(1, slow_i_o);
slow_mem2 ->init_req(1, slow_mem);
slow_reg2 ->init_req(2, *ctrl);
slow_i_o2 ->init_req(2, checked_i_o);
slow_mem2 ->init_req(2, checked_mem);
slow_control = slow_reg2;
slow_i_o = slow_i_o2;
slow_mem = slow_mem2;
if (alloc != NULL) {
// We'll restart from the very beginning, after zeroing the whole thing.
// This can cause double writes, but that's OK since dest is brand new.
// So we ignore the low 31 bits of the value returned from the stub.
} else {
// We must continue the copy exactly where it failed, or else
// another thread might see the wrong number of writes to dest.
Node* checked_offset = new XorINode(checked_value, intcon(-1));
Node* slow_offset = new PhiNode(slow_reg2, TypeInt::INT);
transform_later(checked_offset);
transform_later(slow_offset);
slow_offset->init_req(1, intcon(0));
slow_offset->init_req(2, checked_offset);
// Adjust the arguments by the conditionally incoming offset.
Node* src_off_plus = new AddINode(src_offset, slow_offset);
transform_later(src_off_plus);
Node* dest_off_plus = new AddINode(dest_offset, slow_offset);
transform_later(dest_off_plus);
Node* length_minus = new SubINode(copy_length, slow_offset);
transform_later(length_minus);
// Tweak the node variables to adjust the code produced below:
src_offset = src_off_plus;
dest_offset = dest_off_plus;
copy_length = length_minus;
}
}
*ctrl = slow_control;
if (!(*ctrl)->is_top()) {
Node* local_ctrl = *ctrl, *local_io = slow_i_o;
MergeMemNode* local_mem = MergeMemNode::make(mem);
transform_later(local_mem);
// Generate the slow path, if needed.
local_mem->set_memory_at(alias_idx, slow_mem);
if (dest_uninitialized) {
generate_clear_array(local_ctrl, local_mem,
adr_type, dest, basic_elem_type,
intcon(0), NULL,
alloc->in(AllocateNode::AllocSize));
}
local_mem = generate_slow_arraycopy(ac,
&local_ctrl, local_mem, &local_io,
adr_type,
src, src_offset, dest, dest_offset,
copy_length, /*dest_uninitialized*/false);
result_region->init_req(slow_call_path, local_ctrl);
result_i_o ->init_req(slow_call_path, local_io);
result_memory->init_req(slow_call_path, local_mem->memory_at(alias_idx));
} else {
ShouldNotReachHere(); // no call to generate_slow_arraycopy:
// projections were not extracted
}
// Remove unused edges.
for (uint i = 1; i < result_region->req(); i++) {
if (result_region->in(i) == NULL) {
result_region->init_req(i, top());
}
}
// Finished; return the combined state.
*ctrl = result_region;
*io = result_i_o;
mem->set_memory_at(alias_idx, result_memory);
// mem no longer guaranteed to stay a MergeMemNode
Node* out_mem = mem;
DEBUG_ONLY(mem = NULL);
// The memory edges above are precise in order to model effects around
// array copies accurately to allow value numbering of field loads around
// arraycopy. Such field loads, both before and after, are common in Java
// collections and similar classes involving header/array data structures.
//
// But with low number of register or when some registers are used or killed
// by arraycopy calls it causes registers spilling on stack. See 6544710.
// The next memory barrier is added to avoid it. If the arraycopy can be
// optimized away (which it can, sometimes) then we can manually remove
// the membar also.
//
// Do not let reads from the cloned object float above the arraycopy.
if (alloc != NULL && !alloc->initialization()->does_not_escape()) {
// Do not let stores that initialize this object be reordered with
// a subsequent store that would make this object accessible by
// other threads.
insert_mem_bar(ctrl, &out_mem, Op_MemBarStoreStore);
} else if (InsertMemBarAfterArraycopy) {
insert_mem_bar(ctrl, &out_mem, Op_MemBarCPUOrder);
}
_igvn.replace_node(_memproj_fallthrough, out_mem);
_igvn.replace_node(_ioproj_fallthrough, *io);
_igvn.replace_node(_fallthroughcatchproj, *ctrl);
#ifdef ASSERT
const TypeOopPtr* dest_t = _igvn.type(dest)->is_oopptr();
if (dest_t->is_known_instance()) {
ArrayCopyNode* ac = NULL;
assert(ArrayCopyNode::may_modify(dest_t, (*ctrl)->in(0)->as_MemBar(), &_igvn, ac), "dependency on arraycopy lost");
assert(ac == NULL, "no arraycopy anymore");
}
#endif
return out_mem;
}
// Helper for initialization of arrays, creating a ClearArray.
// It writes zero bits in [start..end), within the body of an array object.
// The memory effects are all chained onto the 'adr_type' alias category.
//
// Since the object is otherwise uninitialized, we are free
// to put a little "slop" around the edges of the cleared area,
// as long as it does not go back into the array's header,
// or beyond the array end within the heap.
//
// The lower edge can be rounded down to the nearest jint and the
// upper edge can be rounded up to the nearest MinObjAlignmentInBytes.
//
// Arguments:
// adr_type memory slice where writes are generated
// dest oop of the destination array
// basic_elem_type element type of the destination
// slice_idx array index of first element to store
// slice_len number of elements to store (or NULL)
// dest_size total size in bytes of the array object
//
// Exactly one of slice_len or dest_size must be non-NULL.
// If dest_size is non-NULL, zeroing extends to the end of the object.
// If slice_len is non-NULL, the slice_idx value must be a constant.
void PhaseMacroExpand::generate_clear_array(Node* ctrl, MergeMemNode* merge_mem,
const TypePtr* adr_type,
Node* dest,
BasicType basic_elem_type,
Node* slice_idx,
Node* slice_len,
Node* dest_size) {
// one or the other but not both of slice_len and dest_size:
assert((slice_len != NULL? 1: 0) + (dest_size != NULL? 1: 0) == 1, "");
if (slice_len == NULL) slice_len = top();
if (dest_size == NULL) dest_size = top();
uint alias_idx = C->get_alias_index(adr_type);
// operate on this memory slice:
Node* mem = merge_mem->memory_at(alias_idx); // memory slice to operate on
// scaling and rounding of indexes:
int scale = exact_log2(type2aelembytes(basic_elem_type));
int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
int clear_low = (-1 << scale) & (BytesPerInt - 1);
int bump_bit = (-1 << scale) & BytesPerInt;
// determine constant starts and ends
const intptr_t BIG_NEG = -128;
assert(BIG_NEG + 2*abase < 0, "neg enough");
intptr_t slice_idx_con = (intptr_t) _igvn.find_int_con(slice_idx, BIG_NEG);
intptr_t slice_len_con = (intptr_t) _igvn.find_int_con(slice_len, BIG_NEG);
if (slice_len_con == 0) {
return; // nothing to do here
}
intptr_t start_con = (abase + (slice_idx_con << scale)) & ~clear_low;
intptr_t end_con = _igvn.find_intptr_t_con(dest_size, -1);
if (slice_idx_con >= 0 && slice_len_con >= 0) {
assert(end_con < 0, "not two cons");
end_con = align_up(abase + ((slice_idx_con + slice_len_con) << scale),
BytesPerLong);
}
if (start_con >= 0 && end_con >= 0) {
// Constant start and end. Simple.
mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
start_con, end_con, &_igvn);
} else if (start_con >= 0 && dest_size != top()) {
// Constant start, pre-rounded end after the tail of the array.
Node* end = dest_size;
mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
start_con, end, &_igvn);
} else if (start_con >= 0 && slice_len != top()) {
// Constant start, non-constant end. End needs rounding up.
// End offset = round_up(abase + ((slice_idx_con + slice_len) << scale), 8)
intptr_t end_base = abase + (slice_idx_con << scale);
int end_round = (-1 << scale) & (BytesPerLong - 1);
Node* end = ConvI2X(slice_len);
if (scale != 0)
end = transform_later(new LShiftXNode(end, intcon(scale) ));
end_base += end_round;
end = transform_later(new AddXNode(end, MakeConX(end_base)) );
end = transform_later(new AndXNode(end, MakeConX(~end_round)) );
mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
start_con, end, &_igvn);
} else if (start_con < 0 && dest_size != top()) {
// Non-constant start, pre-rounded end after the tail of the array.
// This is almost certainly a "round-to-end" operation.
Node* start = slice_idx;
start = ConvI2X(start);
if (scale != 0)
start = transform_later(new LShiftXNode( start, intcon(scale) ));
start = transform_later(new AddXNode(start, MakeConX(abase)) );
if ((bump_bit | clear_low) != 0) {
int to_clear = (bump_bit | clear_low);
// Align up mod 8, then store a jint zero unconditionally
// just before the mod-8 boundary.
if (((abase + bump_bit) & ~to_clear) - bump_bit
< arrayOopDesc::length_offset_in_bytes() + BytesPerInt) {
bump_bit = 0;
assert((abase & to_clear) == 0, "array base must be long-aligned");
} else {
// Bump 'start' up to (or past) the next jint boundary:
start = transform_later( new AddXNode(start, MakeConX(bump_bit)) );
assert((abase & clear_low) == 0, "array base must be int-aligned");
}
// Round bumped 'start' down to jlong boundary in body of array.
start = transform_later(new AndXNode(start, MakeConX(~to_clear)) );
if (bump_bit != 0) {
// Store a zero to the immediately preceding jint:
Node* x1 = transform_later(new AddXNode(start, MakeConX(-bump_bit)) );
Node* p1 = basic_plus_adr(dest, x1);
mem = StoreNode::make(_igvn, ctrl, mem, p1, adr_type, intcon(0), T_INT, MemNode::unordered);
mem = transform_later(mem);
}
}
Node* end = dest_size; // pre-rounded
mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
start, end, &_igvn);
} else {
// Non-constant start, unrounded non-constant end.
// (Nobody zeroes a random midsection of an array using this routine.)
ShouldNotReachHere(); // fix caller
}
// Done.
merge_mem->set_memory_at(alias_idx, mem);
}
bool PhaseMacroExpand::generate_block_arraycopy(Node** ctrl, MergeMemNode** mem, Node* io,
const TypePtr* adr_type,
BasicType basic_elem_type,
AllocateNode* alloc,
Node* src, Node* src_offset,
Node* dest, Node* dest_offset,
Node* dest_size, bool dest_uninitialized) {
// See if there is an advantage from block transfer.
int scale = exact_log2(type2aelembytes(basic_elem_type));
if (scale >= LogBytesPerLong)
return false; // it is already a block transfer
// Look at the alignment of the starting offsets.
int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
intptr_t src_off_con = (intptr_t) _igvn.find_int_con(src_offset, -1);
intptr_t dest_off_con = (intptr_t) _igvn.find_int_con(dest_offset, -1);
if (src_off_con < 0 || dest_off_con < 0) {
// At present, we can only understand constants.
return false;
}
intptr_t src_off = abase + (src_off_con << scale);
intptr_t dest_off = abase + (dest_off_con << scale);
if (((src_off | dest_off) & (BytesPerLong-1)) != 0) {
// Non-aligned; too bad.
// One more chance: Pick off an initial 32-bit word.
// This is a common case, since abase can be odd mod 8.
if (((src_off | dest_off) & (BytesPerLong-1)) == BytesPerInt &&
((src_off ^ dest_off) & (BytesPerLong-1)) == 0) {
Node* sptr = basic_plus_adr(src, src_off);
Node* dptr = basic_plus_adr(dest, dest_off);
const TypePtr* s_adr_type = _igvn.type(sptr)->is_ptr();
assert(s_adr_type->isa_aryptr(), "impossible slice");
uint s_alias_idx = C->get_alias_index(s_adr_type);
uint d_alias_idx = C->get_alias_index(adr_type);
bool is_mismatched = (basic_elem_type != T_INT);
Node* sval = transform_later(
LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(s_alias_idx), sptr, s_adr_type,
TypeInt::INT, T_INT, MemNode::unordered, LoadNode::DependsOnlyOnTest,
false /*unaligned*/, is_mismatched));
Node* st = transform_later(
StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(d_alias_idx), dptr, adr_type,
sval, T_INT, MemNode::unordered));
if (is_mismatched) {
st->as_Store()->set_mismatched_access();
}
(*mem)->set_memory_at(d_alias_idx, st);
src_off += BytesPerInt;
dest_off += BytesPerInt;
} else {
return false;
}
}
assert(src_off % BytesPerLong == 0, "");
assert(dest_off % BytesPerLong == 0, "");
// Do this copy by giant steps.
Node* sptr = basic_plus_adr(src, src_off);
Node* dptr = basic_plus_adr(dest, dest_off);
Node* countx = dest_size;
countx = transform_later(new SubXNode(countx, MakeConX(dest_off)));
countx = transform_later(new URShiftXNode(countx, intcon(LogBytesPerLong)));
bool disjoint_bases = true; // since alloc != NULL
generate_unchecked_arraycopy(ctrl, mem,
adr_type, T_LONG, disjoint_bases,
sptr, NULL, dptr, NULL, countx, dest_uninitialized);
return true;
}
// Helper function; generates code for the slow case.
// We make a call to a runtime method which emulates the native method,
// but without the native wrapper overhead.
MergeMemNode* PhaseMacroExpand::generate_slow_arraycopy(ArrayCopyNode *ac,
Node** ctrl, Node* mem, Node** io,
const TypePtr* adr_type,
Node* src, Node* src_offset,
Node* dest, Node* dest_offset,
Node* copy_length, bool dest_uninitialized) {
assert(!dest_uninitialized, "Invariant");
const TypeFunc* call_type = OptoRuntime::slow_arraycopy_Type();
CallNode* call = new CallStaticJavaNode(call_type, OptoRuntime::slow_arraycopy_Java(),
"slow_arraycopy",
ac->jvms()->bci(), TypePtr::BOTTOM);
call->init_req(TypeFunc::Control, *ctrl);
call->init_req(TypeFunc::I_O , *io);
call->init_req(TypeFunc::Memory , mem);
call->init_req(TypeFunc::ReturnAdr, top());
call->init_req(TypeFunc::FramePtr, top());
call->init_req(TypeFunc::Parms+0, src);
call->init_req(TypeFunc::Parms+1, src_offset);
call->init_req(TypeFunc::Parms+2, dest);
call->init_req(TypeFunc::Parms+3, dest_offset);
call->init_req(TypeFunc::Parms+4, copy_length);
copy_call_debug_info(ac, call);
call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
_igvn.replace_node(ac, call);
transform_later(call);
extract_call_projections(call);
*ctrl = _fallthroughcatchproj->clone();
transform_later(*ctrl);
Node* m = _memproj_fallthrough->clone();
transform_later(m);
uint alias_idx = C->get_alias_index(adr_type);
MergeMemNode* out_mem;
if (alias_idx != Compile::AliasIdxBot) {
out_mem = MergeMemNode::make(mem);
out_mem->set_memory_at(alias_idx, m);
} else {
out_mem = MergeMemNode::make(m);
}
transform_later(out_mem);
*io = _ioproj_fallthrough->clone();
transform_later(*io);
return out_mem;
}
// Helper function; generates code for cases requiring runtime checks.
Node* PhaseMacroExpand::generate_checkcast_arraycopy(Node** ctrl, MergeMemNode** mem,
const TypePtr* adr_type,
Node* dest_elem_klass,
Node* src, Node* src_offset,
Node* dest, Node* dest_offset,
Node* copy_length, bool dest_uninitialized) {
if ((*ctrl)->is_top()) return NULL;
address copyfunc_addr = StubRoutines::checkcast_arraycopy(dest_uninitialized);
if (copyfunc_addr == NULL) { // Stub was not generated, go slow path.
return NULL;
}
// Pick out the parameters required to perform a store-check
// for the target array. This is an optimistic check. It will
// look in each non-null element's class, at the desired klass's
// super_check_offset, for the desired klass.
int sco_offset = in_bytes(Klass::super_check_offset_offset());
Node* p3 = basic_plus_adr(dest_elem_klass, sco_offset);
Node* n3 = new LoadINode(NULL, *mem /*memory(p3)*/, p3, _igvn.type(p3)->is_ptr(), TypeInt::INT, MemNode::unordered);
Node* check_offset = ConvI2X(transform_later(n3));
Node* check_value = dest_elem_klass;
Node* src_start = array_element_address(src, src_offset, T_OBJECT);
Node* dest_start = array_element_address(dest, dest_offset, T_OBJECT);
const TypeFunc* call_type = OptoRuntime::checkcast_arraycopy_Type();
Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "checkcast_arraycopy", adr_type,
src_start, dest_start, copy_length XTOP, check_offset XTOP, check_value);
finish_arraycopy_call(call, ctrl, mem, adr_type);
Node* proj = new ProjNode(call, TypeFunc::Parms);
transform_later(proj);
return proj;
}
// Helper function; generates code for cases requiring runtime checks.
Node* PhaseMacroExpand::generate_generic_arraycopy(Node** ctrl, MergeMemNode** mem,
const TypePtr* adr_type,
Node* src, Node* src_offset,
Node* dest, Node* dest_offset,
Node* copy_length, bool dest_uninitialized) {
if ((*ctrl)->is_top()) return NULL;
assert(!dest_uninitialized, "Invariant");
address copyfunc_addr = StubRoutines::generic_arraycopy();
if (copyfunc_addr == NULL) { // Stub was not generated, go slow path.
return NULL;
}
const TypeFunc* call_type = OptoRuntime::generic_arraycopy_Type();
Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "generic_arraycopy", adr_type,
src, src_offset, dest, dest_offset, copy_length);
finish_arraycopy_call(call, ctrl, mem, adr_type);
Node* proj = new ProjNode(call, TypeFunc::Parms);
transform_later(proj);
return proj;
}
// Helper function; generates the fast out-of-line call to an arraycopy stub.
void PhaseMacroExpand::generate_unchecked_arraycopy(Node** ctrl, MergeMemNode** mem,
const TypePtr* adr_type,
BasicType basic_elem_type,
bool disjoint_bases,
Node* src, Node* src_offset,
Node* dest, Node* dest_offset,
Node* copy_length, bool dest_uninitialized) {
if ((*ctrl)->is_top()) return;
Node* src_start = src;
Node* dest_start = dest;
if (src_offset != NULL || dest_offset != NULL) {
src_start = array_element_address(src, src_offset, basic_elem_type);
dest_start = array_element_address(dest, dest_offset, basic_elem_type);
}
// Figure out which arraycopy runtime method to call.
const char* copyfunc_name = "arraycopy";
address copyfunc_addr =
basictype2arraycopy(basic_elem_type, src_offset, dest_offset,
disjoint_bases, copyfunc_name, dest_uninitialized);
const TypeFunc* call_type = OptoRuntime::fast_arraycopy_Type();
Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, copyfunc_name, adr_type,
src_start, dest_start, copy_length XTOP);
finish_arraycopy_call(call, ctrl, mem, adr_type);
}
void PhaseMacroExpand::expand_arraycopy_node(ArrayCopyNode *ac) {
Node* ctrl = ac->in(TypeFunc::Control);
Node* io = ac->in(TypeFunc::I_O);
Node* src = ac->in(ArrayCopyNode::Src);
Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
Node* dest = ac->in(ArrayCopyNode::Dest);
Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
Node* length = ac->in(ArrayCopyNode::Length);
MergeMemNode* merge_mem = NULL;
if (ac->is_clonebasic()) {
BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
bs->clone_at_expansion(this, ac);
return;
} else if (ac->is_copyof() || ac->is_copyofrange() || ac->is_clone_oop_array()) {
Node* mem = ac->in(TypeFunc::Memory);
merge_mem = MergeMemNode::make(mem);
transform_later(merge_mem);
RegionNode* slow_region = new RegionNode(1);
transform_later(slow_region);
AllocateArrayNode* alloc = NULL;
if (ac->is_alloc_tightly_coupled()) {
alloc = AllocateArrayNode::Ideal_array_allocation(dest, &_igvn);
assert(alloc != NULL, "expect alloc");
}
const TypePtr* adr_type = _igvn.type(dest)->is_oopptr()->add_offset(Type::OffsetBot);
if (ac->_dest_type != TypeOopPtr::BOTTOM) {
adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
}
generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
adr_type, T_OBJECT,
src, src_offset, dest, dest_offset, length,
true, !ac->is_copyofrange());
return;
}
AllocateArrayNode* alloc = NULL;
if (ac->is_alloc_tightly_coupled()) {
alloc = AllocateArrayNode::Ideal_array_allocation(dest, &_igvn);
assert(alloc != NULL, "expect alloc");
}
assert(ac->is_arraycopy() || ac->is_arraycopy_validated(), "should be an arraycopy");
// Compile time checks. If any of these checks cannot be verified at compile time,
// we do not make a fast path for this call. Instead, we let the call remain as it
// is. The checks we choose to mandate at compile time are:
//
// (1) src and dest are arrays.
const Type* src_type = src->Value(&_igvn);
const Type* dest_type = dest->Value(&_igvn);
const TypeAryPtr* top_src = src_type->isa_aryptr();
const TypeAryPtr* top_dest = dest_type->isa_aryptr();
BasicType src_elem = T_CONFLICT;
BasicType dest_elem = T_CONFLICT;
if (top_dest != NULL && top_dest->klass() != NULL) {
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