6800154: Add comments to long_by_long_mulhi() for better understandability
Summary: This patch adds a comment pointing to the Hacker's Delight version of the algorithm plus a verbatim copy of it. Furthermore it adds inline comments.
Reviewed-by: kvn, jrose
/*
* Copyright 2004-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
# include "incls/_precompiled.incl"
# include "incls/_jniFastGetField_sparc.cpp.incl"
// TSO ensures that loads are blocking and ordered with respect to
// to earlier loads, so we don't need LoadLoad membars.
#define __ masm->
#define BUFFER_SIZE 30*sizeof(jint)
// Common register usage:
// O0: env
// O1: obj
// O2: jfieldID
// O4: offset (O2 >> 2)
// G4: old safepoint counter
address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
const char *name;
switch (type) {
case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
case T_BYTE: name = "jni_fast_GetByteField"; break;
case T_CHAR: name = "jni_fast_GetCharField"; break;
case T_SHORT: name = "jni_fast_GetShortField"; break;
case T_INT: name = "jni_fast_GetIntField"; break;
default: ShouldNotReachHere();
}
ResourceMark rm;
BufferBlob* b = BufferBlob::create(name, BUFFER_SIZE*wordSize);
address fast_entry = b->instructions_begin();
CodeBuffer cbuf(fast_entry, b->instructions_size());
MacroAssembler* masm = new MacroAssembler(&cbuf);
Label label1, label2;
address cnt_addr = SafepointSynchronize::safepoint_counter_addr();
Address ca(O3, cnt_addr);
__ sethi (ca);
__ ld (ca, G4);
__ andcc (G4, 1, G0);
__ br (Assembler::notZero, false, Assembler::pn, label1);
__ delayed()->srl (O2, 2, O4);
__ ld_ptr (O1, 0, O5);
assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
speculative_load_pclist[count] = __ pc();
switch (type) {
case T_BOOLEAN: __ ldub (O5, O4, G3); break;
case T_BYTE: __ ldsb (O5, O4, G3); break;
case T_CHAR: __ lduh (O5, O4, G3); break;
case T_SHORT: __ ldsh (O5, O4, G3); break;
case T_INT: __ ld (O5, O4, G3); break;
default: ShouldNotReachHere();
}
__ ld (ca, O5);
__ cmp (O5, G4);
__ br (Assembler::notEqual, false, Assembler::pn, label2);
__ delayed()->mov (O7, G1);
__ retl ();
__ delayed()->mov (G3, O0);
slowcase_entry_pclist[count++] = __ pc();
__ bind (label1);
__ mov (O7, G1);
address slow_case_addr;
switch (type) {
case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break;
case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break;
case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break;
case T_INT: slow_case_addr = jni_GetIntField_addr(); break;
default: ShouldNotReachHere();
}
__ bind (label2);
__ call (slow_case_addr, relocInfo::none);
__ delayed()->mov (G1, O7);
__ flush ();
return fast_entry;
}
address JNI_FastGetField::generate_fast_get_boolean_field() {
return generate_fast_get_int_field0(T_BOOLEAN);
}
address JNI_FastGetField::generate_fast_get_byte_field() {
return generate_fast_get_int_field0(T_BYTE);
}
address JNI_FastGetField::generate_fast_get_char_field() {
return generate_fast_get_int_field0(T_CHAR);
}
address JNI_FastGetField::generate_fast_get_short_field() {
return generate_fast_get_int_field0(T_SHORT);
}
address JNI_FastGetField::generate_fast_get_int_field() {
return generate_fast_get_int_field0(T_INT);
}
address JNI_FastGetField::generate_fast_get_long_field() {
const char *name = "jni_fast_GetLongField";
ResourceMark rm;
BufferBlob* b = BufferBlob::create(name, BUFFER_SIZE*wordSize);
address fast_entry = b->instructions_begin();
CodeBuffer cbuf(fast_entry, b->instructions_size());
MacroAssembler* masm = new MacroAssembler(&cbuf);
Label label1, label2;
address cnt_addr = SafepointSynchronize::safepoint_counter_addr();
Address ca(G3, cnt_addr);
__ sethi (ca);
__ ld (ca, G4);
__ andcc (G4, 1, G0);
__ br (Assembler::notZero, false, Assembler::pn, label1);
__ delayed()->srl (O2, 2, O4);
__ ld_ptr (O1, 0, O5);
__ add (O5, O4, O5);
#ifndef _LP64
assert(count < LIST_CAPACITY-1, "LIST_CAPACITY too small");
speculative_load_pclist[count++] = __ pc();
__ ld (O5, 0, G2);
speculative_load_pclist[count] = __ pc();
__ ld (O5, 4, O3);
#else
assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
speculative_load_pclist[count] = __ pc();
__ ldx (O5, 0, O3);
#endif
__ ld (ca, G1);
__ cmp (G1, G4);
__ br (Assembler::notEqual, false, Assembler::pn, label2);
__ delayed()->mov (O7, G1);
#ifndef _LP64
__ mov (G2, O0);
__ retl ();
__ delayed()->mov (O3, O1);
#else
__ retl ();
__ delayed()->mov (O3, O0);
#endif
#ifndef _LP64
slowcase_entry_pclist[count-1] = __ pc();
slowcase_entry_pclist[count++] = __ pc() ;
#else
slowcase_entry_pclist[count++] = __ pc();
#endif
__ bind (label1);
__ mov (O7, G1);
address slow_case_addr = jni_GetLongField_addr();
__ bind (label2);
__ call (slow_case_addr, relocInfo::none);
__ delayed()->mov (G1, O7);
__ flush ();
return fast_entry;
}
address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
const char *name;
switch (type) {
case T_FLOAT: name = "jni_fast_GetFloatField"; break;
case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
default: ShouldNotReachHere();
}
ResourceMark rm;
BufferBlob* b = BufferBlob::create(name, BUFFER_SIZE*wordSize);
address fast_entry = b->instructions_begin();
CodeBuffer cbuf(fast_entry, b->instructions_size());
MacroAssembler* masm = new MacroAssembler(&cbuf);
Label label1, label2;
address cnt_addr = SafepointSynchronize::safepoint_counter_addr();
Address ca(O3, cnt_addr);
__ sethi (ca);
__ ld (ca, G4);
__ andcc (G4, 1, G0);
__ br (Assembler::notZero, false, Assembler::pn, label1);
__ delayed()->srl (O2, 2, O4);
__ ld_ptr (O1, 0, O5);
assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
speculative_load_pclist[count] = __ pc();
switch (type) {
case T_FLOAT: __ ldf (FloatRegisterImpl::S, O5, O4, F0); break;
case T_DOUBLE: __ ldf (FloatRegisterImpl::D, O5, O4, F0); break;
default: ShouldNotReachHere();
}
__ ld (ca, O5);
__ cmp (O5, G4);
__ br (Assembler::notEqual, false, Assembler::pn, label2);
__ delayed()->mov (O7, G1);
__ retl ();
__ delayed()-> nop ();
slowcase_entry_pclist[count++] = __ pc();
__ bind (label1);
__ mov (O7, G1);
address slow_case_addr;
switch (type) {
case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break;
case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
default: ShouldNotReachHere();
}
__ bind (label2);
__ call (slow_case_addr, relocInfo::none);
__ delayed()->mov (G1, O7);
__ flush ();
return fast_entry;
}
address JNI_FastGetField::generate_fast_get_float_field() {
return generate_fast_get_float_field0(T_FLOAT);
}
address JNI_FastGetField::generate_fast_get_double_field() {
return generate_fast_get_float_field0(T_DOUBLE);
}