archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-23 20:44:41 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8149096: Remove unused code in methodComparator

Browse source 
Remove unused code in methodComparator

Reviewed-by: coleenp, sspitsyn, dholmes
This commit is contained in:
Thomas Stuefe 2016-02-11 02:39:35 -08:00
parent 4096556cc6
commit 1245e4138c
2 changed files with 12 additions and 220 deletions
Download patch file Download diff file Expand all files Collapse all files

152
hotspot/src/share/vm/prims/methodComparator.cpp
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2016, 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
@ -34,9 +34,6 @@ BytecodeStream *MethodComparator::_s_old;
BytecodeStream *MethodComparator::_s_new;
ConstantPool* MethodComparator::_old_cp;
ConstantPool* MethodComparator::_new_cp;
BciMap *MethodComparator::_bci_map;
bool MethodComparator::_switchable_test;
GrowableArray<int> *MethodComparator::_fwd_jmps;
bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) {
if (old_method->code_size() != new_method->code_size())
@ -55,7 +52,6 @@ bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) {
BytecodeStream s_new(new_method);
_s_old = &s_old;
_s_new = &s_new;
_switchable_test = false;
Bytecodes::Code c_old, c_new;
while ((c_old = s_old.next()) >= 0) {
@ -68,64 +64,6 @@ bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) {
return true;
}
bool MethodComparator::methods_switchable(Method* old_method, Method* new_method,
BciMap &bci_map) {
if (old_method->code_size() > new_method->code_size())
// Something has definitely been deleted in the new method, compared to the old one.
return false;
if (! check_stack_and_locals_size(old_method, new_method))
return false;
_old_cp = old_method->constants();
_new_cp = new_method->constants();
BytecodeStream s_old(old_method);
BytecodeStream s_new(new_method);
_s_old = &s_old;
_s_new = &s_new;
_bci_map = &bci_map;
_switchable_test = true;
GrowableArray<int> fwd_jmps(16);
_fwd_jmps = &fwd_jmps;
Bytecodes::Code c_old, c_new;
while ((c_old = s_old.next()) >= 0) {
if ((c_new = s_new.next()) < 0)
return false;
if (! (c_old == c_new && args_same(c_old, c_new))) {
int old_bci = s_old.bci();
int new_st_bci = s_new.bci();
bool found_match = false;
do {
c_new = s_new.next();
if (c_new == c_old && args_same(c_old, c_new)) {
found_match = true;
break;
}
} while (c_new >= 0);
if (! found_match)
return false;
int new_end_bci = s_new.bci();
bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);
}
}
// Now we can test all forward jumps
for (int i = 0; i < fwd_jmps.length() / 2; i++) {
if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
RC_TRACE(0x00800000,
("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
fwd_jmps.at(i*2+1)));
return false;
}
}
return true;
}
bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
// BytecodeStream returns the correct standard Java bytecodes for various "fast"
// bytecode versions, so we don't have to bother about them here..
@ -275,22 +213,8 @@ bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
case Bytecodes::_jsr : {
int old_ofs = _s_old->bytecode().get_offset_s2(c_old);
int new_ofs = _s_new->bytecode().get_offset_s2(c_new);
if (_switchable_test) {
int old_dest = _s_old->bci() + old_ofs;
int new_dest = _s_new->bci() + new_ofs;
if (old_ofs < 0 && new_ofs < 0) {
if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
return false;
} else if (old_ofs > 0 && new_ofs > 0) {
_fwd_jmps->append(old_dest);
_fwd_jmps->append(new_dest);
} else {
return false;
}
} else {
if (old_ofs != new_ofs)
return false;
}
if (old_ofs != new_ofs)
return false;
break;
}
@ -312,73 +236,19 @@ bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
case Bytecodes::_jsr_w : {
int old_ofs = _s_old->bytecode().get_offset_s4(c_old);
int new_ofs = _s_new->bytecode().get_offset_s4(c_new);
if (_switchable_test) {
int old_dest = _s_old->bci() + old_ofs;
int new_dest = _s_new->bci() + new_ofs;
if (old_ofs < 0 && new_ofs < 0) {
if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
return false;
} else if (old_ofs > 0 && new_ofs > 0) {
_fwd_jmps->append(old_dest);
_fwd_jmps->append(new_dest);
} else {
return false;
}
} else {
if (old_ofs != new_ofs)
return false;
}
if (old_ofs != new_ofs)
return false;
break;
}
case Bytecodes::_lookupswitch : // fall through
case Bytecodes::_tableswitch : {
if (_switchable_test) {
address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
_fwd_jmps->append(_s_old->bci() + default_old);
_fwd_jmps->append(_s_new->bci() + default_new);
if (c_old == Bytecodes::_lookupswitch) {
int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
if (npairs_old != npairs_new)
return false;
for (int i = 0; i < npairs_old; i++) {
int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
if (match_old != match_new)
return false;
int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
_fwd_jmps->append(_s_old->bci() + ofs_old);
_fwd_jmps->append(_s_new->bci() + ofs_new);
}
} else if (c_old == Bytecodes::_tableswitch) {
int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
if (lo_old != lo_new)
return false;
int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
if (hi_old != hi_new)
return false;
for (int i = 0; i < hi_old - lo_old + 1; i++) {
int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
_fwd_jmps->append(_s_old->bci() + ofs_old);
_fwd_jmps->append(_s_new->bci() + ofs_new);
}
}
} else { // !_switchable_test, can use fast rough compare
int len_old = _s_old->instruction_size();
int len_new = _s_new->instruction_size();
if (len_old != len_new)
return false;
if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
return false;
}
int len_old = _s_old->instruction_size();
int len_new = _s_new->instruction_size();
if (len_old != len_new)
return false;
if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
return false;
break;
}
}

80
hotspot/src/share/vm/prims/methodComparator.hpp
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2016, 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
@ -29,8 +29,6 @@
#include "oops/constantPool.hpp"
#include "oops/method.hpp"
class BciMap;
// methodComparator provides an interface for determining if methods of
// different versions of classes are equivalent or switchable
@ -39,9 +37,6 @@ class MethodComparator {
static BytecodeStream *_s_old, *_s_new;
static ConstantPool* _old_cp;
static ConstantPool* _new_cp;
static BciMap *_bci_map;
static bool _switchable_test;
static GrowableArray<int> *_fwd_jmps;
static bool args_same(Bytecodes::Code c_old, Bytecodes::Code c_new);
static bool pool_constants_same(int cpi_old, int cpi_new);
@ -55,79 +50,6 @@ class MethodComparator {
// these indices eventually point to the same constants for both method versions.
static bool methods_EMCP(Method* old_method, Method* new_method);
static bool methods_switchable(Method* old_method, Method* new_method, BciMap &bci_map);
};
// ByteCode Index Map. For two versions of the same method, where the new version may contain
// fragments not found in the old version, provides a mapping from an index of a bytecode in
// the old method to the index of the same bytecode in the new method.
class BciMap {
private:
int *_old_bci, *_new_st_bci, *_new_end_bci;
int _cur_size, _cur_pos;
int _pos;
public:
BciMap() {
_cur_size = 50;
_old_bci = (int*) malloc(sizeof(int) * _cur_size);
_new_st_bci = (int*) malloc(sizeof(int) * _cur_size);
_new_end_bci = (int*) malloc(sizeof(int) * _cur_size);
_cur_pos = 0;
}
~BciMap() {
free(_old_bci);
free(_new_st_bci);
free(_new_end_bci);
}
// Store the position of an added fragment, e.g.
//
// |<- old_bci
// -----------------------------------------
// Old method |invokevirtual 5|aload 1|...
// -----------------------------------------
//
// |<- new_st_bci |<- new_end_bci
// --------------------------------------------------------------------
// New method |invokevirual 5|aload 2|invokevirtual 6|aload 1|...
// --------------------------------------------------------------------
// ^^^^^^^^^^^^^^^^^^^^^^^^
// Added fragment
void store_fragment_location(int old_bci, int new_st_bci, int new_end_bci) {
if (_cur_pos == _cur_size) {
_cur_size += 10;
_old_bci = (int*) realloc(_old_bci, sizeof(int) * _cur_size);
_new_st_bci = (int*) realloc(_new_st_bci, sizeof(int) * _cur_size);
_new_end_bci = (int*) realloc(_new_end_bci, sizeof(int) * _cur_size);
}
_old_bci[_cur_pos] = old_bci;
_new_st_bci[_cur_pos] = new_st_bci;
_new_end_bci[_cur_pos] = new_end_bci;
_cur_pos++;
}
int new_bci_for_old(int old_bci) {
if (_cur_pos == 0 || old_bci < _old_bci[0]) return old_bci;
_pos = 1;
while (_pos < _cur_pos && old_bci >= _old_bci[_pos])
_pos++;
return _new_end_bci[_pos-1] + (old_bci - _old_bci[_pos-1]);
}
// Test if two indexes - one in the old method and another in the new one - correspond
// to the same bytecode
bool old_and_new_locations_same(int old_dest_bci, int new_dest_bci) {
if (new_bci_for_old(old_dest_bci) == new_dest_bci)
return true;
else if (_old_bci[_pos-1] == old_dest_bci)
return (new_dest_bci == _new_st_bci[_pos-1]);
else return false;
}
};
#endif // SHARE_VM_PRIMS_METHODCOMPARATOR_HPP