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7033154: Improve C1 arraycopy performance

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Better static analysis. Take advantage of array copy stubs.

Reviewed-by: never
This commit is contained in:
Roland Westrelin 2011-04-03 12:00:54 +02:00
parent 00eca5e982
commit f94d7776ca
13 changed files with 720 additions and 146 deletions
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113
hotspot/src/share/vm/c1/c1_LIRGenerator.cpp
View file

@ -706,6 +706,38 @@ static ciArrayKlass* as_array_klass(ciType* type) {
}
}
static Value maxvalue(IfOp* ifop) {
switch (ifop->cond()) {
case If::eql: return NULL;
case If::neq: return NULL;
case If::lss: // x < y ? x : y
case If::leq: // x <= y ? x : y
if (ifop->x() == ifop->tval() &&
ifop->y() == ifop->fval()) return ifop->y();
return NULL;
case If::gtr: // x > y ? y : x
case If::geq: // x >= y ? y : x
if (ifop->x() == ifop->tval() &&
ifop->y() == ifop->fval()) return ifop->y();
return NULL;
}
}
static ciType* phi_declared_type(Phi* phi) {
ciType* t = phi->operand_at(0)->declared_type();
if (t == NULL) {
return NULL;
}
for(int i = 1; i < phi->operand_count(); i++) {
if (t != phi->operand_at(i)->declared_type()) {
return NULL;
}
}
return t;
}
void LIRGenerator::arraycopy_helper(Intrinsic* x, int* flagsp, ciArrayKlass** expected_typep) {
Instruction* src = x->argument_at(0);
Instruction* src_pos = x->argument_at(1);
@ -715,12 +747,20 @@ void LIRGenerator::arraycopy_helper(Intrinsic* x, int* flagsp, ciArrayKlass** ex
// first try to identify the likely type of the arrays involved
ciArrayKlass* expected_type = NULL;
bool is_exact = false;
bool is_exact = false, src_objarray = false, dst_objarray = false;
{
ciArrayKlass* src_exact_type = as_array_klass(src->exact_type());
ciArrayKlass* src_declared_type = as_array_klass(src->declared_type());
Phi* phi;
if (src_declared_type == NULL && (phi = src->as_Phi()) != NULL) {
src_declared_type = as_array_klass(phi_declared_type(phi));
}
ciArrayKlass* dst_exact_type = as_array_klass(dst->exact_type());
ciArrayKlass* dst_declared_type = as_array_klass(dst->declared_type());
if (dst_declared_type == NULL && (phi = dst->as_Phi()) != NULL) {
dst_declared_type = as_array_klass(phi_declared_type(phi));
}
if (src_exact_type != NULL && src_exact_type == dst_exact_type) {
// the types exactly match so the type is fully known
is_exact = true;
@ -744,17 +784,60 @@ void LIRGenerator::arraycopy_helper(Intrinsic* x, int* flagsp, ciArrayKlass** ex
if (expected_type == NULL) expected_type = dst_exact_type;
if (expected_type == NULL) expected_type = src_declared_type;
if (expected_type == NULL) expected_type = dst_declared_type;
src_objarray = (src_exact_type && src_exact_type->is_obj_array_klass()) || (src_declared_type && src_declared_type->is_obj_array_klass());
dst_objarray = (dst_exact_type && dst_exact_type->is_obj_array_klass()) || (dst_declared_type && dst_declared_type->is_obj_array_klass());
}
// if a probable array type has been identified, figure out if any
// of the required checks for a fast case can be elided.
int flags = LIR_OpArrayCopy::all_flags;
if (!src_objarray)
flags &= ~LIR_OpArrayCopy::src_objarray;
if (!dst_objarray)
flags &= ~LIR_OpArrayCopy::dst_objarray;
if (!x->arg_needs_null_check(0))
flags &= ~LIR_OpArrayCopy::src_null_check;
if (!x->arg_needs_null_check(2))
flags &= ~LIR_OpArrayCopy::dst_null_check;
if (expected_type != NULL) {
// try to skip null checks
if (src->as_NewArray() != NULL)
Value length_limit = NULL;
IfOp* ifop = length->as_IfOp();
if (ifop != NULL) {
// look for expressions like min(v, a.length) which ends up as
// x > y ? y : x or x >= y ? y : x
if ((ifop->cond() == If::gtr || ifop->cond() == If::geq) &&
ifop->x() == ifop->fval() &&
ifop->y() == ifop->tval()) {
length_limit = ifop->y();
}
}
// try to skip null checks and range checks
NewArray* src_array = src->as_NewArray();
if (src_array != NULL) {
flags &= ~LIR_OpArrayCopy::src_null_check;
if (dst->as_NewArray() != NULL)
if (length_limit != NULL &&
src_array->length() == length_limit &&
is_constant_zero(src_pos)) {
flags &= ~LIR_OpArrayCopy::src_range_check;
}
}
NewArray* dst_array = dst->as_NewArray();
if (dst_array != NULL) {
flags &= ~LIR_OpArrayCopy::dst_null_check;
if (length_limit != NULL &&
dst_array->length() == length_limit &&
is_constant_zero(dst_pos)) {
flags &= ~LIR_OpArrayCopy::dst_range_check;
}
}
// check from incoming constant values
if (positive_constant(src_pos))
@ -788,6 +871,28 @@ void LIRGenerator::arraycopy_helper(Intrinsic* x, int* flagsp, ciArrayKlass** ex
}
}
IntConstant* src_int = src_pos->type()->as_IntConstant();
IntConstant* dst_int = dst_pos->type()->as_IntConstant();
if (src_int && dst_int) {
int s_offs = src_int->value();
int d_offs = dst_int->value();
if (src_int->value() >= dst_int->value()) {
flags &= ~LIR_OpArrayCopy::overlapping;
}
if (expected_type != NULL) {
BasicType t = expected_type->element_type()->basic_type();
int element_size = type2aelembytes(t);
if (((arrayOopDesc::base_offset_in_bytes(t) + s_offs * element_size) % HeapWordSize == 0) &&
((arrayOopDesc::base_offset_in_bytes(t) + d_offs * element_size) % HeapWordSize == 0)) {
flags &= ~LIR_OpArrayCopy::unaligned;
}
}
} else if (src_pos == dst_pos || is_constant_zero(dst_pos)) {
// src and dest positions are the same, or dst is zero so assume
// nonoverlapping copy.
flags &= ~LIR_OpArrayCopy::overlapping;
}
if (src == dst) {
// moving within a single array so no type checks are needed
if (flags & LIR_OpArrayCopy::type_check) {