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 2000-2007 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.
*
*/
// forward declaration
class Address;
class VMRegImpl;
typedef VMRegImpl* VMReg;
// Use Register as shortcut
class RegisterImpl;
typedef RegisterImpl* Register;
inline Register as_Register(int encoding) {
return (Register)(intptr_t) encoding;
}
// The implementation of integer registers for the SPARC architecture
class RegisterImpl: public AbstractRegisterImpl {
public:
enum {
log_set_size = 3, // the number of bits to encode the set register number
number_of_sets = 4, // the number of registers sets (in, local, out, global)
number_of_registers = number_of_sets << log_set_size,
iset_no = 3, ibase = iset_no << log_set_size, // the in register set
lset_no = 2, lbase = lset_no << log_set_size, // the local register set
oset_no = 1, obase = oset_no << log_set_size, // the output register set
gset_no = 0, gbase = gset_no << log_set_size // the global register set
};
friend Register as_Register(int encoding);
// set specific construction
friend Register as_iRegister(int number);
friend Register as_lRegister(int number);
friend Register as_oRegister(int number);
friend Register as_gRegister(int number);
VMReg as_VMReg();
// accessors
int encoding() const { assert(is_valid(), "invalid register"); return value(); }
const char* name() const;
// testers
bool is_valid() const { return (0 <= (value()&0x7F) && (value()&0x7F) < number_of_registers); }
bool is_even() const { return (encoding() & 1) == 0; }
bool is_in() const { return (encoding() >> log_set_size) == iset_no; }
bool is_local() const { return (encoding() >> log_set_size) == lset_no; }
bool is_out() const { return (encoding() >> log_set_size) == oset_no; }
bool is_global() const { return (encoding() >> log_set_size) == gset_no; }
// derived registers, offsets, and addresses
Register successor() const { return as_Register(encoding() + 1); }
int input_number() const {
assert(is_in(), "must be input register");
return encoding() - ibase;
}
Register after_save() const {
assert(is_out() || is_global(), "register not visible after save");
return is_out() ? as_Register(encoding() + (ibase - obase)) : (const Register)this;
}
Register after_restore() const {
assert(is_in() || is_global(), "register not visible after restore");
return is_in() ? as_Register(encoding() + (obase - ibase)) : (const Register)this;
}
int sp_offset_in_saved_window() const {
assert(is_in() || is_local(), "only i and l registers are saved in frame");
return encoding() - lbase;
}
inline Address address_in_saved_window() const; // implemented in assembler_sparc.hpp
};
// set specific construction
inline Register as_iRegister(int number) { return as_Register(RegisterImpl::ibase + number); }
inline Register as_lRegister(int number) { return as_Register(RegisterImpl::lbase + number); }
inline Register as_oRegister(int number) { return as_Register(RegisterImpl::obase + number); }
inline Register as_gRegister(int number) { return as_Register(RegisterImpl::gbase + number); }
// The integer registers of the SPARC architecture
CONSTANT_REGISTER_DECLARATION(Register, noreg , (-1));
CONSTANT_REGISTER_DECLARATION(Register, G0 , (RegisterImpl::gbase + 0));
CONSTANT_REGISTER_DECLARATION(Register, G1 , (RegisterImpl::gbase + 1));
CONSTANT_REGISTER_DECLARATION(Register, G2 , (RegisterImpl::gbase + 2));
CONSTANT_REGISTER_DECLARATION(Register, G3 , (RegisterImpl::gbase + 3));
CONSTANT_REGISTER_DECLARATION(Register, G4 , (RegisterImpl::gbase + 4));
CONSTANT_REGISTER_DECLARATION(Register, G5 , (RegisterImpl::gbase + 5));
CONSTANT_REGISTER_DECLARATION(Register, G6 , (RegisterImpl::gbase + 6));
CONSTANT_REGISTER_DECLARATION(Register, G7 , (RegisterImpl::gbase + 7));
CONSTANT_REGISTER_DECLARATION(Register, O0 , (RegisterImpl::obase + 0));
CONSTANT_REGISTER_DECLARATION(Register, O1 , (RegisterImpl::obase + 1));
CONSTANT_REGISTER_DECLARATION(Register, O2 , (RegisterImpl::obase + 2));
CONSTANT_REGISTER_DECLARATION(Register, O3 , (RegisterImpl::obase + 3));
CONSTANT_REGISTER_DECLARATION(Register, O4 , (RegisterImpl::obase + 4));
CONSTANT_REGISTER_DECLARATION(Register, O5 , (RegisterImpl::obase + 5));
CONSTANT_REGISTER_DECLARATION(Register, O6 , (RegisterImpl::obase + 6));
CONSTANT_REGISTER_DECLARATION(Register, O7 , (RegisterImpl::obase + 7));
CONSTANT_REGISTER_DECLARATION(Register, L0 , (RegisterImpl::lbase + 0));
CONSTANT_REGISTER_DECLARATION(Register, L1 , (RegisterImpl::lbase + 1));
CONSTANT_REGISTER_DECLARATION(Register, L2 , (RegisterImpl::lbase + 2));
CONSTANT_REGISTER_DECLARATION(Register, L3 , (RegisterImpl::lbase + 3));
CONSTANT_REGISTER_DECLARATION(Register, L4 , (RegisterImpl::lbase + 4));
CONSTANT_REGISTER_DECLARATION(Register, L5 , (RegisterImpl::lbase + 5));
CONSTANT_REGISTER_DECLARATION(Register, L6 , (RegisterImpl::lbase + 6));
CONSTANT_REGISTER_DECLARATION(Register, L7 , (RegisterImpl::lbase + 7));
CONSTANT_REGISTER_DECLARATION(Register, I0 , (RegisterImpl::ibase + 0));
CONSTANT_REGISTER_DECLARATION(Register, I1 , (RegisterImpl::ibase + 1));
CONSTANT_REGISTER_DECLARATION(Register, I2 , (RegisterImpl::ibase + 2));
CONSTANT_REGISTER_DECLARATION(Register, I3 , (RegisterImpl::ibase + 3));
CONSTANT_REGISTER_DECLARATION(Register, I4 , (RegisterImpl::ibase + 4));
CONSTANT_REGISTER_DECLARATION(Register, I5 , (RegisterImpl::ibase + 5));
CONSTANT_REGISTER_DECLARATION(Register, I6 , (RegisterImpl::ibase + 6));
CONSTANT_REGISTER_DECLARATION(Register, I7 , (RegisterImpl::ibase + 7));
CONSTANT_REGISTER_DECLARATION(Register, FP , (RegisterImpl::ibase + 6));
CONSTANT_REGISTER_DECLARATION(Register, SP , (RegisterImpl::obase + 6));
//
// Because sparc has so many registers, #define'ing values for the is
// beneficial in code size and the cost of some of the dangers of
// defines. We don't use them on Intel because win32 uses asm
// directives which use the same names for registers as Hotspot does,
// so #defines would screw up the inline assembly. If a particular
// file has a problem with these defines then it's possible to turn
// them off in that file by defining DONT_USE_REGISTER_DEFINES.
// register_definition_sparc.cpp does that so that it's able to
// provide real definitions of these registers for use in debuggers
// and such.
//
#ifndef DONT_USE_REGISTER_DEFINES
#define noreg ((Register)(noreg_RegisterEnumValue))
#define G0 ((Register)(G0_RegisterEnumValue))
#define G1 ((Register)(G1_RegisterEnumValue))
#define G2 ((Register)(G2_RegisterEnumValue))
#define G3 ((Register)(G3_RegisterEnumValue))
#define G4 ((Register)(G4_RegisterEnumValue))
#define G5 ((Register)(G5_RegisterEnumValue))
#define G6 ((Register)(G6_RegisterEnumValue))
#define G7 ((Register)(G7_RegisterEnumValue))
#define O0 ((Register)(O0_RegisterEnumValue))
#define O1 ((Register)(O1_RegisterEnumValue))
#define O2 ((Register)(O2_RegisterEnumValue))
#define O3 ((Register)(O3_RegisterEnumValue))
#define O4 ((Register)(O4_RegisterEnumValue))
#define O5 ((Register)(O5_RegisterEnumValue))
#define O6 ((Register)(O6_RegisterEnumValue))
#define O7 ((Register)(O7_RegisterEnumValue))
#define L0 ((Register)(L0_RegisterEnumValue))
#define L1 ((Register)(L1_RegisterEnumValue))
#define L2 ((Register)(L2_RegisterEnumValue))
#define L3 ((Register)(L3_RegisterEnumValue))
#define L4 ((Register)(L4_RegisterEnumValue))
#define L5 ((Register)(L5_RegisterEnumValue))
#define L6 ((Register)(L6_RegisterEnumValue))
#define L7 ((Register)(L7_RegisterEnumValue))
#define I0 ((Register)(I0_RegisterEnumValue))
#define I1 ((Register)(I1_RegisterEnumValue))
#define I2 ((Register)(I2_RegisterEnumValue))
#define I3 ((Register)(I3_RegisterEnumValue))
#define I4 ((Register)(I4_RegisterEnumValue))
#define I5 ((Register)(I5_RegisterEnumValue))
#define I6 ((Register)(I6_RegisterEnumValue))
#define I7 ((Register)(I7_RegisterEnumValue))
#define FP ((Register)(FP_RegisterEnumValue))
#define SP ((Register)(SP_RegisterEnumValue))
#endif // DONT_USE_REGISTER_DEFINES
// Use FloatRegister as shortcut
class FloatRegisterImpl;
typedef FloatRegisterImpl* FloatRegister;
// construction
inline FloatRegister as_FloatRegister(int encoding) {
return (FloatRegister)(intptr_t)encoding;
}
// The implementation of float registers for the SPARC architecture
class FloatRegisterImpl: public AbstractRegisterImpl {
public:
enum {
number_of_registers = 64
};
enum Width {
S = 1, D = 2, Q = 3
};
// construction
VMReg as_VMReg( );
// accessors
int encoding() const { assert(is_valid(), "invalid register"); return value(); }
public:
int encoding(Width w) const {
const int c = encoding();
switch (w) {
case S:
assert(c < 32, "bad single float register");
return c;
case D:
assert(c < 64 && (c & 1) == 0, "bad double float register");
assert(c < 32 || VM_Version::v9_instructions_work(), "V9 float work only on V9 platform");
return (c & 0x1e) | ((c & 0x20) >> 5);
case Q:
assert(c < 64 && (c & 3) == 0, "bad quad float register");
assert(c < 32 || VM_Version::v9_instructions_work(), "V9 float work only on V9 platform");
return (c & 0x1c) | ((c & 0x20) >> 5);
}
ShouldNotReachHere();
return -1;
}
bool is_valid() const { return 0 <= value() && value() < number_of_registers; }
const char* name() const;
FloatRegister successor() const { return as_FloatRegister(encoding() + 1); }
};
// The float registers of the SPARC architecture
CONSTANT_REGISTER_DECLARATION(FloatRegister, fnoreg , (-1));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F0 , ( 0));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F1 , ( 1));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F2 , ( 2));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F3 , ( 3));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F4 , ( 4));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F5 , ( 5));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F6 , ( 6));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F7 , ( 7));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F8 , ( 8));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F9 , ( 9));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F10 , (10));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F11 , (11));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F12 , (12));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F13 , (13));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F14 , (14));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F15 , (15));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F16 , (16));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F17 , (17));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F18 , (18));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F19 , (19));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F20 , (20));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F21 , (21));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F22 , (22));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F23 , (23));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F24 , (24));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F25 , (25));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F26 , (26));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F27 , (27));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F28 , (28));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F29 , (29));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F30 , (30));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F31 , (31));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F32 , (32));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F34 , (34));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F36 , (36));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F38 , (38));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F40 , (40));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F42 , (42));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F44 , (44));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F46 , (46));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F48 , (48));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F50 , (50));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F52 , (52));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F54 , (54));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F56 , (56));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F58 , (58));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F60 , (60));
CONSTANT_REGISTER_DECLARATION(FloatRegister, F62 , (62));
#ifndef DONT_USE_REGISTER_DEFINES
#define fnoreg ((FloatRegister)(fnoreg_FloatRegisterEnumValue))
#define F0 ((FloatRegister)( F0_FloatRegisterEnumValue))
#define F1 ((FloatRegister)( F1_FloatRegisterEnumValue))
#define F2 ((FloatRegister)( F2_FloatRegisterEnumValue))
#define F3 ((FloatRegister)( F3_FloatRegisterEnumValue))
#define F4 ((FloatRegister)( F4_FloatRegisterEnumValue))
#define F5 ((FloatRegister)( F5_FloatRegisterEnumValue))
#define F6 ((FloatRegister)( F6_FloatRegisterEnumValue))
#define F7 ((FloatRegister)( F7_FloatRegisterEnumValue))
#define F8 ((FloatRegister)( F8_FloatRegisterEnumValue))
#define F9 ((FloatRegister)( F9_FloatRegisterEnumValue))
#define F10 ((FloatRegister)( F10_FloatRegisterEnumValue))
#define F11 ((FloatRegister)( F11_FloatRegisterEnumValue))
#define F12 ((FloatRegister)( F12_FloatRegisterEnumValue))
#define F13 ((FloatRegister)( F13_FloatRegisterEnumValue))
#define F14 ((FloatRegister)( F14_FloatRegisterEnumValue))
#define F15 ((FloatRegister)( F15_FloatRegisterEnumValue))
#define F16 ((FloatRegister)( F16_FloatRegisterEnumValue))
#define F17 ((FloatRegister)( F17_FloatRegisterEnumValue))
#define F18 ((FloatRegister)( F18_FloatRegisterEnumValue))
#define F19 ((FloatRegister)( F19_FloatRegisterEnumValue))
#define F20 ((FloatRegister)( F20_FloatRegisterEnumValue))
#define F21 ((FloatRegister)( F21_FloatRegisterEnumValue))
#define F22 ((FloatRegister)( F22_FloatRegisterEnumValue))
#define F23 ((FloatRegister)( F23_FloatRegisterEnumValue))
#define F24 ((FloatRegister)( F24_FloatRegisterEnumValue))
#define F25 ((FloatRegister)( F25_FloatRegisterEnumValue))
#define F26 ((FloatRegister)( F26_FloatRegisterEnumValue))
#define F27 ((FloatRegister)( F27_FloatRegisterEnumValue))
#define F28 ((FloatRegister)( F28_FloatRegisterEnumValue))
#define F29 ((FloatRegister)( F29_FloatRegisterEnumValue))
#define F30 ((FloatRegister)( F30_FloatRegisterEnumValue))
#define F31 ((FloatRegister)( F31_FloatRegisterEnumValue))
#define F32 ((FloatRegister)( F32_FloatRegisterEnumValue))
#define F34 ((FloatRegister)( F34_FloatRegisterEnumValue))
#define F36 ((FloatRegister)( F36_FloatRegisterEnumValue))
#define F38 ((FloatRegister)( F38_FloatRegisterEnumValue))
#define F40 ((FloatRegister)( F40_FloatRegisterEnumValue))
#define F42 ((FloatRegister)( F42_FloatRegisterEnumValue))
#define F44 ((FloatRegister)( F44_FloatRegisterEnumValue))
#define F46 ((FloatRegister)( F46_FloatRegisterEnumValue))
#define F48 ((FloatRegister)( F48_FloatRegisterEnumValue))
#define F50 ((FloatRegister)( F50_FloatRegisterEnumValue))
#define F52 ((FloatRegister)( F52_FloatRegisterEnumValue))
#define F54 ((FloatRegister)( F54_FloatRegisterEnumValue))
#define F56 ((FloatRegister)( F56_FloatRegisterEnumValue))
#define F58 ((FloatRegister)( F58_FloatRegisterEnumValue))
#define F60 ((FloatRegister)( F60_FloatRegisterEnumValue))
#define F62 ((FloatRegister)( F62_FloatRegisterEnumValue))
#endif // DONT_USE_REGISTER_DEFINES
// Maximum number of incoming arguments that can be passed in i registers.
const int SPARC_ARGS_IN_REGS_NUM = 6;
class ConcreteRegisterImpl : public AbstractRegisterImpl {
public:
enum {
// This number must be large enough to cover REG_COUNT (defined by c2) registers.
// There is no requirement that any ordering here matches any ordering c2 gives
// it's optoregs.
number_of_registers = 2*RegisterImpl::number_of_registers +
FloatRegisterImpl::number_of_registers +
1 + // ccr
4 // fcc
};
static const int max_gpr;
static const int max_fpr;
};
// Single, Double and Quad fp reg classes. These exist to map the ADLC
// encoding for a floating point register, to the FloatRegister number
// desired by the macroassembler. A FloatRegister is a number between
// 0 and 63 passed around as a pointer. For ADLC, an fp register encoding
// is the actual bit encoding used by the sparc hardware. When ADLC used
// the macroassembler to generate an instruction that references, e.g., a
// double fp reg, it passed the bit encoding to the macroassembler via
// as_FloatRegister, which, for double regs > 30, returns an illegal
// register number.
//
// Therefore we provide the following classes for use by ADLC. Their
// sole purpose is to convert from sparc register encodings to FloatRegisters.
// At some future time, we might replace FloatRegister with these classes,
// hence the definitions of as_xxxFloatRegister as class methods rather
// than as external inline routines.
class SingleFloatRegisterImpl;
typedef SingleFloatRegisterImpl *SingleFloatRegister;
inline FloatRegister as_SingleFloatRegister(int encoding);
class SingleFloatRegisterImpl {
public:
friend inline FloatRegister as_SingleFloatRegister(int encoding) {
assert(encoding < 32, "bad single float register encoding");
return as_FloatRegister(encoding);
}
};
class DoubleFloatRegisterImpl;
typedef DoubleFloatRegisterImpl *DoubleFloatRegister;
inline FloatRegister as_DoubleFloatRegister(int encoding);
class DoubleFloatRegisterImpl {
public:
friend inline FloatRegister as_DoubleFloatRegister(int encoding) {
assert(encoding < 32, "bad double float register encoding");
return as_FloatRegister( ((encoding & 1) << 5) | (encoding & 0x1e) );
}
};
class QuadFloatRegisterImpl;
typedef QuadFloatRegisterImpl *QuadFloatRegister;
class QuadFloatRegisterImpl {
public:
friend FloatRegister as_QuadFloatRegister(int encoding) {
assert(encoding < 32 && ((encoding & 2) == 0), "bad quad float register encoding");
return as_FloatRegister( ((encoding & 1) << 5) | (encoding & 0x1c) );
}
};