8227127: Era designator not displayed correctly using the COMPAT provider
Reviewed-by: rriggs
/*
* Copyright (c) 1997, 2017, 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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* questions.
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*/
#include "precompiled.hpp"
#include "code/compressedStream.hpp"
#include "utilities/ostream.hpp"
// 32-bit self-inverse encoding of float bits
// converts trailing zeroes (common in floats) to leading zeroes
inline juint CompressedStream::reverse_int(juint i) {
// Hacker's Delight, Figure 7-1
i = (i & 0x55555555) << 1 | ((i >> 1) & 0x55555555);
i = (i & 0x33333333) << 2 | ((i >> 2) & 0x33333333);
i = (i & 0x0f0f0f0f) << 4 | ((i >> 4) & 0x0f0f0f0f);
i = (i << 24) | ((i & 0xff00) << 8) | ((i >> 8) & 0xff00) | (i >> 24);
return i;
}
jint CompressedReadStream::read_signed_int() {
return decode_sign(read_int());
}
// Compressing floats is simple, because the only common pattern
// is trailing zeroes. (Compare leading sign bits on ints.)
// Since floats are left-justified, as opposed to right-justified
// ints, we can bit-reverse them in order to take advantage of int
// compression.
jfloat CompressedReadStream::read_float() {
int rf = read_int();
int f = reverse_int(rf);
return jfloat_cast(f);
}
jdouble CompressedReadStream::read_double() {
jint rh = read_int();
jint rl = read_int();
jint h = reverse_int(rh);
jint l = reverse_int(rl);
return jdouble_cast(jlong_from(h, l));
}
jlong CompressedReadStream::read_long() {
jint low = read_signed_int();
jint high = read_signed_int();
return jlong_from(high, low);
}
CompressedWriteStream::CompressedWriteStream(int initial_size) : CompressedStream(NULL, 0) {
_buffer = NEW_RESOURCE_ARRAY(u_char, initial_size);
_size = initial_size;
_position = 0;
}
void CompressedWriteStream::grow() {
u_char* _new_buffer = NEW_RESOURCE_ARRAY(u_char, _size * 2);
memcpy(_new_buffer, _buffer, _position);
_buffer = _new_buffer;
_size = _size * 2;
}
void CompressedWriteStream::write_float(jfloat value) {
juint f = jint_cast(value);
juint rf = reverse_int(f);
assert(f == reverse_int(rf), "can re-read same bits");
write_int(rf);
}
void CompressedWriteStream::write_double(jdouble value) {
juint h = high(jlong_cast(value));
juint l = low( jlong_cast(value));
juint rh = reverse_int(h);
juint rl = reverse_int(l);
assert(h == reverse_int(rh), "can re-read same bits");
assert(l == reverse_int(rl), "can re-read same bits");
write_int(rh);
write_int(rl);
}
void CompressedWriteStream::write_long(jlong value) {
write_signed_int(low(value));
write_signed_int(high(value));
}