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 1999-2006 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/_c1_FrameMap_sparc.cpp.incl"
const int FrameMap::pd_c_runtime_reserved_arg_size = 7;
LIR_Opr FrameMap::map_to_opr(BasicType type, VMRegPair* reg, bool outgoing) {
LIR_Opr opr = LIR_OprFact::illegalOpr;
VMReg r_1 = reg->first();
VMReg r_2 = reg->second();
if (r_1->is_stack()) {
// Convert stack slot to an SP offset
// The calling convention does not count the SharedRuntime::out_preserve_stack_slots() value
// so we must add it in here.
int st_off = (r_1->reg2stack() + SharedRuntime::out_preserve_stack_slots()) * VMRegImpl::stack_slot_size;
opr = LIR_OprFact::address(new LIR_Address(SP_opr, st_off + STACK_BIAS, type));
} else if (r_1->is_Register()) {
Register reg = r_1->as_Register();
if (outgoing) {
assert(!reg->is_in(), "should be using I regs");
} else {
assert(!reg->is_out(), "should be using O regs");
}
if (r_2->is_Register() && (type == T_LONG || type == T_DOUBLE)) {
opr = as_long_opr(reg);
} else if (type == T_OBJECT || type == T_ARRAY) {
opr = as_oop_opr(reg);
} else {
opr = as_opr(reg);
}
} else if (r_1->is_FloatRegister()) {
assert(type == T_DOUBLE || type == T_FLOAT, "wrong type");
FloatRegister f = r_1->as_FloatRegister();
if (type == T_DOUBLE) {
opr = as_double_opr(f);
} else {
opr = as_float_opr(f);
}
}
return opr;
}
// FrameMap
//--------------------------------------------------------
FloatRegister FrameMap::_fpu_regs [FrameMap::nof_fpu_regs];
// some useful constant RInfo's:
LIR_Opr FrameMap::in_long_opr;
LIR_Opr FrameMap::out_long_opr;
LIR_Opr FrameMap::F0_opr;
LIR_Opr FrameMap::F0_double_opr;
LIR_Opr FrameMap::G0_opr;
LIR_Opr FrameMap::G1_opr;
LIR_Opr FrameMap::G2_opr;
LIR_Opr FrameMap::G3_opr;
LIR_Opr FrameMap::G4_opr;
LIR_Opr FrameMap::G5_opr;
LIR_Opr FrameMap::G6_opr;
LIR_Opr FrameMap::G7_opr;
LIR_Opr FrameMap::O0_opr;
LIR_Opr FrameMap::O1_opr;
LIR_Opr FrameMap::O2_opr;
LIR_Opr FrameMap::O3_opr;
LIR_Opr FrameMap::O4_opr;
LIR_Opr FrameMap::O5_opr;
LIR_Opr FrameMap::O6_opr;
LIR_Opr FrameMap::O7_opr;
LIR_Opr FrameMap::L0_opr;
LIR_Opr FrameMap::L1_opr;
LIR_Opr FrameMap::L2_opr;
LIR_Opr FrameMap::L3_opr;
LIR_Opr FrameMap::L4_opr;
LIR_Opr FrameMap::L5_opr;
LIR_Opr FrameMap::L6_opr;
LIR_Opr FrameMap::L7_opr;
LIR_Opr FrameMap::I0_opr;
LIR_Opr FrameMap::I1_opr;
LIR_Opr FrameMap::I2_opr;
LIR_Opr FrameMap::I3_opr;
LIR_Opr FrameMap::I4_opr;
LIR_Opr FrameMap::I5_opr;
LIR_Opr FrameMap::I6_opr;
LIR_Opr FrameMap::I7_opr;
LIR_Opr FrameMap::G0_oop_opr;
LIR_Opr FrameMap::G1_oop_opr;
LIR_Opr FrameMap::G2_oop_opr;
LIR_Opr FrameMap::G3_oop_opr;
LIR_Opr FrameMap::G4_oop_opr;
LIR_Opr FrameMap::G5_oop_opr;
LIR_Opr FrameMap::G6_oop_opr;
LIR_Opr FrameMap::G7_oop_opr;
LIR_Opr FrameMap::O0_oop_opr;
LIR_Opr FrameMap::O1_oop_opr;
LIR_Opr FrameMap::O2_oop_opr;
LIR_Opr FrameMap::O3_oop_opr;
LIR_Opr FrameMap::O4_oop_opr;
LIR_Opr FrameMap::O5_oop_opr;
LIR_Opr FrameMap::O6_oop_opr;
LIR_Opr FrameMap::O7_oop_opr;
LIR_Opr FrameMap::L0_oop_opr;
LIR_Opr FrameMap::L1_oop_opr;
LIR_Opr FrameMap::L2_oop_opr;
LIR_Opr FrameMap::L3_oop_opr;
LIR_Opr FrameMap::L4_oop_opr;
LIR_Opr FrameMap::L5_oop_opr;
LIR_Opr FrameMap::L6_oop_opr;
LIR_Opr FrameMap::L7_oop_opr;
LIR_Opr FrameMap::I0_oop_opr;
LIR_Opr FrameMap::I1_oop_opr;
LIR_Opr FrameMap::I2_oop_opr;
LIR_Opr FrameMap::I3_oop_opr;
LIR_Opr FrameMap::I4_oop_opr;
LIR_Opr FrameMap::I5_oop_opr;
LIR_Opr FrameMap::I6_oop_opr;
LIR_Opr FrameMap::I7_oop_opr;
LIR_Opr FrameMap::SP_opr;
LIR_Opr FrameMap::FP_opr;
LIR_Opr FrameMap::Oexception_opr;
LIR_Opr FrameMap::Oissuing_pc_opr;
LIR_Opr FrameMap::_caller_save_cpu_regs[] = { 0, };
LIR_Opr FrameMap::_caller_save_fpu_regs[] = { 0, };
FloatRegister FrameMap::nr2floatreg (int rnr) {
assert(_init_done, "tables not initialized");
debug_only(fpu_range_check(rnr);)
return _fpu_regs[rnr];
}
// returns true if reg could be smashed by a callee.
bool FrameMap::is_caller_save_register (LIR_Opr reg) {
if (reg->is_single_fpu() || reg->is_double_fpu()) { return true; }
if (reg->is_double_cpu()) {
return is_caller_save_register(reg->as_register_lo()) ||
is_caller_save_register(reg->as_register_hi());
}
return is_caller_save_register(reg->as_register());
}
NEEDS_CLEANUP // once the new calling convention is enabled, we no
// longer need to treat I5, I4 and L0 specially
// Because the interpreter destroys caller's I5, I4 and L0,
// we must spill them before doing a Java call as we may land in
// interpreter.
bool FrameMap::is_caller_save_register (Register r) {
return (r->is_global() && (r != G0)) || r->is_out();
}
void FrameMap::init () {
if (_init_done) return;
int i=0;
// Register usage:
// O6: sp
// I6: fp
// I7: return address
// G0: zero
// G2: thread
// G7: not available
// G6: not available
/* 0 */ map_register(i++, L0);
/* 1 */ map_register(i++, L1);
/* 2 */ map_register(i++, L2);
/* 3 */ map_register(i++, L3);
/* 4 */ map_register(i++, L4);
/* 5 */ map_register(i++, L5);
/* 6 */ map_register(i++, L6);
/* 7 */ map_register(i++, L7);
/* 8 */ map_register(i++, I0);
/* 9 */ map_register(i++, I1);
/* 10 */ map_register(i++, I2);
/* 11 */ map_register(i++, I3);
/* 12 */ map_register(i++, I4);
/* 13 */ map_register(i++, I5);
/* 14 */ map_register(i++, O0);
/* 15 */ map_register(i++, O1);
/* 16 */ map_register(i++, O2);
/* 17 */ map_register(i++, O3);
/* 18 */ map_register(i++, O4);
/* 19 */ map_register(i++, O5); // <- last register visible in RegAlloc (RegAlloc::nof+cpu_regs)
/* 20 */ map_register(i++, G1);
/* 21 */ map_register(i++, G3);
/* 22 */ map_register(i++, G4);
/* 23 */ map_register(i++, G5);
/* 24 */ map_register(i++, G0);
// the following registers are not normally available
/* 25 */ map_register(i++, O7);
/* 26 */ map_register(i++, G2);
/* 27 */ map_register(i++, O6);
/* 28 */ map_register(i++, I6);
/* 29 */ map_register(i++, I7);
/* 30 */ map_register(i++, G6);
/* 31 */ map_register(i++, G7);
assert(i == nof_cpu_regs, "number of CPU registers");
for (i = 0; i < nof_fpu_regs; i++) {
_fpu_regs[i] = as_FloatRegister(i);
}
_init_done = true;
in_long_opr = as_long_opr(I0);
out_long_opr = as_long_opr(O0);
G0_opr = as_opr(G0);
G1_opr = as_opr(G1);
G2_opr = as_opr(G2);
G3_opr = as_opr(G3);
G4_opr = as_opr(G4);
G5_opr = as_opr(G5);
G6_opr = as_opr(G6);
G7_opr = as_opr(G7);
O0_opr = as_opr(O0);
O1_opr = as_opr(O1);
O2_opr = as_opr(O2);
O3_opr = as_opr(O3);
O4_opr = as_opr(O4);
O5_opr = as_opr(O5);
O6_opr = as_opr(O6);
O7_opr = as_opr(O7);
L0_opr = as_opr(L0);
L1_opr = as_opr(L1);
L2_opr = as_opr(L2);
L3_opr = as_opr(L3);
L4_opr = as_opr(L4);
L5_opr = as_opr(L5);
L6_opr = as_opr(L6);
L7_opr = as_opr(L7);
I0_opr = as_opr(I0);
I1_opr = as_opr(I1);
I2_opr = as_opr(I2);
I3_opr = as_opr(I3);
I4_opr = as_opr(I4);
I5_opr = as_opr(I5);
I6_opr = as_opr(I6);
I7_opr = as_opr(I7);
G0_oop_opr = as_oop_opr(G0);
G1_oop_opr = as_oop_opr(G1);
G2_oop_opr = as_oop_opr(G2);
G3_oop_opr = as_oop_opr(G3);
G4_oop_opr = as_oop_opr(G4);
G5_oop_opr = as_oop_opr(G5);
G6_oop_opr = as_oop_opr(G6);
G7_oop_opr = as_oop_opr(G7);
O0_oop_opr = as_oop_opr(O0);
O1_oop_opr = as_oop_opr(O1);
O2_oop_opr = as_oop_opr(O2);
O3_oop_opr = as_oop_opr(O3);
O4_oop_opr = as_oop_opr(O4);
O5_oop_opr = as_oop_opr(O5);
O6_oop_opr = as_oop_opr(O6);
O7_oop_opr = as_oop_opr(O7);
L0_oop_opr = as_oop_opr(L0);
L1_oop_opr = as_oop_opr(L1);
L2_oop_opr = as_oop_opr(L2);
L3_oop_opr = as_oop_opr(L3);
L4_oop_opr = as_oop_opr(L4);
L5_oop_opr = as_oop_opr(L5);
L6_oop_opr = as_oop_opr(L6);
L7_oop_opr = as_oop_opr(L7);
I0_oop_opr = as_oop_opr(I0);
I1_oop_opr = as_oop_opr(I1);
I2_oop_opr = as_oop_opr(I2);
I3_oop_opr = as_oop_opr(I3);
I4_oop_opr = as_oop_opr(I4);
I5_oop_opr = as_oop_opr(I5);
I6_oop_opr = as_oop_opr(I6);
I7_oop_opr = as_oop_opr(I7);
FP_opr = as_pointer_opr(FP);
SP_opr = as_pointer_opr(SP);
F0_opr = as_float_opr(F0);
F0_double_opr = as_double_opr(F0);
Oexception_opr = as_oop_opr(Oexception);
Oissuing_pc_opr = as_opr(Oissuing_pc);
_caller_save_cpu_regs[0] = FrameMap::O0_opr;
_caller_save_cpu_regs[1] = FrameMap::O1_opr;
_caller_save_cpu_regs[2] = FrameMap::O2_opr;
_caller_save_cpu_regs[3] = FrameMap::O3_opr;
_caller_save_cpu_regs[4] = FrameMap::O4_opr;
_caller_save_cpu_regs[5] = FrameMap::O5_opr;
for (int i = 0; i < nof_caller_save_fpu_regs; i++) {
_caller_save_fpu_regs[i] = LIR_OprFact::single_fpu(i);
}
}
Address FrameMap::make_new_address(ByteSize sp_offset) const {
return Address(SP, 0, STACK_BIAS + in_bytes(sp_offset));
}
VMReg FrameMap::fpu_regname (int n) {
return as_FloatRegister(n)->as_VMReg();
}
LIR_Opr FrameMap::stack_pointer() {
return SP_opr;
}
bool FrameMap::validate_frame() {
int max_offset = in_bytes(framesize_in_bytes());
int java_index = 0;
for (int i = 0; i < _incoming_arguments->length(); i++) {
LIR_Opr opr = _incoming_arguments->at(i);
if (opr->is_stack()) {
max_offset = MAX2(_argument_locations->at(java_index), max_offset);
}
java_index += type2size[opr->type()];
}
return Assembler::is_simm13(max_offset + STACK_BIAS);
}