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 1997-2007 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.
*
*/
#include "incls/_precompiled.incl"
#include "incls/_interpreter_sparc.cpp.incl"
// Generation of Interpreter
//
// The InterpreterGenerator generates the interpreter into Interpreter::_code.
#define __ _masm->
//----------------------------------------------------------------------------------------------------
int AbstractInterpreter::BasicType_as_index(BasicType type) {
int i = 0;
switch (type) {
case T_BOOLEAN: i = 0; break;
case T_CHAR : i = 1; break;
case T_BYTE : i = 2; break;
case T_SHORT : i = 3; break;
case T_INT : i = 4; break;
case T_LONG : i = 5; break;
case T_VOID : i = 6; break;
case T_FLOAT : i = 7; break;
case T_DOUBLE : i = 8; break;
case T_OBJECT : i = 9; break;
case T_ARRAY : i = 9; break;
default : ShouldNotReachHere();
}
assert(0 <= i && i < AbstractInterpreter::number_of_result_handlers, "index out of bounds");
return i;
}
#ifndef _LP64
address AbstractInterpreterGenerator::generate_slow_signature_handler() {
address entry = __ pc();
Argument argv(0, true);
// We are in the jni transition frame. Save the last_java_frame corresponding to the
// outer interpreter frame
//
__ set_last_Java_frame(FP, noreg);
// make sure the interpreter frame we've pushed has a valid return pc
__ mov(O7, I7);
__ mov(Lmethod, G3_scratch);
__ mov(Llocals, G4_scratch);
__ save_frame(0);
__ mov(G2_thread, L7_thread_cache);
__ add(argv.address_in_frame(), O3);
__ mov(G2_thread, O0);
__ mov(G3_scratch, O1);
__ call(CAST_FROM_FN_PTR(address, InterpreterRuntime::slow_signature_handler), relocInfo::runtime_call_type);
__ delayed()->mov(G4_scratch, O2);
__ mov(L7_thread_cache, G2_thread);
__ reset_last_Java_frame();
// load the register arguments (the C code packed them as varargs)
for (Argument ldarg = argv.successor(); ldarg.is_register(); ldarg = ldarg.successor()) {
__ ld_ptr(ldarg.address_in_frame(), ldarg.as_register());
}
__ ret();
__ delayed()->
restore(O0, 0, Lscratch); // caller's Lscratch gets the result handler
return entry;
}
#else
// LP64 passes floating point arguments in F1, F3, F5, etc. instead of
// O0, O1, O2 etc..
// Doubles are passed in D0, D2, D4
// We store the signature of the first 16 arguments in the first argument
// slot because it will be overwritten prior to calling the native
// function, with the pointer to the JNIEnv.
// If LP64 there can be up to 16 floating point arguments in registers
// or 6 integer registers.
address AbstractInterpreterGenerator::generate_slow_signature_handler() {
enum {
non_float = 0,
float_sig = 1,
double_sig = 2,
sig_mask = 3
};
address entry = __ pc();
Argument argv(0, true);
// We are in the jni transition frame. Save the last_java_frame corresponding to the
// outer interpreter frame
//
__ set_last_Java_frame(FP, noreg);
// make sure the interpreter frame we've pushed has a valid return pc
__ mov(O7, I7);
__ mov(Lmethod, G3_scratch);
__ mov(Llocals, G4_scratch);
__ save_frame(0);
__ mov(G2_thread, L7_thread_cache);
__ add(argv.address_in_frame(), O3);
__ mov(G2_thread, O0);
__ mov(G3_scratch, O1);
__ call(CAST_FROM_FN_PTR(address, InterpreterRuntime::slow_signature_handler), relocInfo::runtime_call_type);
__ delayed()->mov(G4_scratch, O2);
__ mov(L7_thread_cache, G2_thread);
__ reset_last_Java_frame();
// load the register arguments (the C code packed them as varargs)
Address Sig = argv.address_in_frame(); // Argument 0 holds the signature
__ ld_ptr( Sig, G3_scratch ); // Get register argument signature word into G3_scratch
__ mov( G3_scratch, G4_scratch);
__ srl( G4_scratch, 2, G4_scratch); // Skip Arg 0
Label done;
for (Argument ldarg = argv.successor(); ldarg.is_float_register(); ldarg = ldarg.successor()) {
Label NonFloatArg;
Label LoadFloatArg;
Label LoadDoubleArg;
Label NextArg;
Address a = ldarg.address_in_frame();
__ andcc(G4_scratch, sig_mask, G3_scratch);
__ br(Assembler::zero, false, Assembler::pt, NonFloatArg);
__ delayed()->nop();
__ cmp(G3_scratch, float_sig );
__ br(Assembler::equal, false, Assembler::pt, LoadFloatArg);
__ delayed()->nop();
__ cmp(G3_scratch, double_sig );
__ br(Assembler::equal, false, Assembler::pt, LoadDoubleArg);
__ delayed()->nop();
__ bind(NonFloatArg);
// There are only 6 integer register arguments!
if ( ldarg.is_register() )
__ ld_ptr(ldarg.address_in_frame(), ldarg.as_register());
else {
// Optimization, see if there are any more args and get out prior to checking
// all 16 float registers. My guess is that this is rare.
// If is_register is false, then we are done the first six integer args.
__ tst(G4_scratch);
__ brx(Assembler::zero, false, Assembler::pt, done);
__ delayed()->nop();
}
__ ba(false, NextArg);
__ delayed()->srl( G4_scratch, 2, G4_scratch );
__ bind(LoadFloatArg);
__ ldf( FloatRegisterImpl::S, a, ldarg.as_float_register(), 4);
__ ba(false, NextArg);
__ delayed()->srl( G4_scratch, 2, G4_scratch );
__ bind(LoadDoubleArg);
__ ldf( FloatRegisterImpl::D, a, ldarg.as_double_register() );
__ ba(false, NextArg);
__ delayed()->srl( G4_scratch, 2, G4_scratch );
__ bind(NextArg);
}
__ bind(done);
__ ret();
__ delayed()->
restore(O0, 0, Lscratch); // caller's Lscratch gets the result handler
return entry;
}
#endif
void InterpreterGenerator::generate_counter_overflow(Label& Lcontinue) {
// Generate code to initiate compilation on the counter overflow.
// InterpreterRuntime::frequency_counter_overflow takes two arguments,
// the first indicates if the counter overflow occurs at a backwards branch (NULL bcp)
// and the second is only used when the first is true. We pass zero for both.
// The call returns the address of the verified entry point for the method or NULL
// if the compilation did not complete (either went background or bailed out).
__ set((int)false, O2);
__ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::frequency_counter_overflow), O2, O2, true);
// returns verified_entry_point or NULL
// we ignore it in any case
__ ba(false, Lcontinue);
__ delayed()->nop();
}
// End of helpers
// Various method entries
// Abstract method entry
// Attempt to execute abstract method. Throw exception
//
address InterpreterGenerator::generate_abstract_entry(void) {
address entry = __ pc();
// abstract method entry
// throw exception
__ call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_AbstractMethodError));
// the call_VM checks for exception, so we should never return here.
__ should_not_reach_here();
return entry;
}
//----------------------------------------------------------------------------------------------------
// Entry points & stack frame layout
//
// Here we generate the various kind of entries into the interpreter.
// The two main entry type are generic bytecode methods and native call method.
// These both come in synchronized and non-synchronized versions but the
// frame layout they create is very similar. The other method entry
// types are really just special purpose entries that are really entry
// and interpretation all in one. These are for trivial methods like
// accessor, empty, or special math methods.
//
// When control flow reaches any of the entry types for the interpreter
// the following holds ->
//
// C2 Calling Conventions:
//
// The entry code below assumes that the following registers are set
// when coming in:
// G5_method: holds the methodOop of the method to call
// Lesp: points to the TOS of the callers expression stack
// after having pushed all the parameters
//
// The entry code does the following to setup an interpreter frame
// pop parameters from the callers stack by adjusting Lesp
// set O0 to Lesp
// compute X = (max_locals - num_parameters)
// bump SP up by X to accomadate the extra locals
// compute X = max_expression_stack
// + vm_local_words
// + 16 words of register save area
// save frame doing a save sp, -X, sp growing towards lower addresses
// set Lbcp, Lmethod, LcpoolCache
// set Llocals to i0
// set Lmonitors to FP - rounded_vm_local_words
// set Lesp to Lmonitors - 4
//
// The frame has now been setup to do the rest of the entry code
// Try this optimization: Most method entries could live in a
// "one size fits all" stack frame without all the dynamic size
// calculations. It might be profitable to do all this calculation
// statically and approximately for "small enough" methods.
//-----------------------------------------------------------------------------------------------
// C1 Calling conventions
//
// Upon method entry, the following registers are setup:
//
// g2 G2_thread: current thread
// g5 G5_method: method to activate
// g4 Gargs : pointer to last argument
//
//
// Stack:
//
// +---------------+ <--- sp
// | |
// : reg save area :
// | |
// +---------------+ <--- sp + 0x40
// | |
// : extra 7 slots : note: these slots are not really needed for the interpreter (fix later)
// | |
// +---------------+ <--- sp + 0x5c
// | |
// : free :
// | |
// +---------------+ <--- Gargs
// | |
// : arguments :
// | |
// +---------------+
// | |
//
//
//
// AFTER FRAME HAS BEEN SETUP for method interpretation the stack looks like:
//
// +---------------+ <--- sp
// | |
// : reg save area :
// | |
// +---------------+ <--- sp + 0x40
// | |
// : extra 7 slots : note: these slots are not really needed for the interpreter (fix later)
// | |
// +---------------+ <--- sp + 0x5c
// | |
// : :
// | | <--- Lesp
// +---------------+ <--- Lmonitors (fp - 0x18)
// | VM locals |
// +---------------+ <--- fp
// | |
// : reg save area :
// | |
// +---------------+ <--- fp + 0x40
// | |
// : extra 7 slots : note: these slots are not really needed for the interpreter (fix later)
// | |
// +---------------+ <--- fp + 0x5c
// | |
// : free :
// | |
// +---------------+
// | |
// : nonarg locals :
// | |
// +---------------+
// | |
// : arguments :
// | | <--- Llocals
// +---------------+ <--- Gargs
// | |
address AbstractInterpreterGenerator::generate_method_entry(AbstractInterpreter::MethodKind kind) {
// determine code generation flags
bool synchronized = false;
address entry_point = NULL;
switch (kind) {
case Interpreter::zerolocals : break;
case Interpreter::zerolocals_synchronized: synchronized = true; break;
case Interpreter::native : entry_point = ((InterpreterGenerator*)this)->generate_native_entry(false); break;
case Interpreter::native_synchronized : entry_point = ((InterpreterGenerator*)this)->generate_native_entry(true); break;
case Interpreter::empty : entry_point = ((InterpreterGenerator*)this)->generate_empty_entry(); break;
case Interpreter::accessor : entry_point = ((InterpreterGenerator*)this)->generate_accessor_entry(); break;
case Interpreter::abstract : entry_point = ((InterpreterGenerator*)this)->generate_abstract_entry(); break;
case Interpreter::java_lang_math_sin : break;
case Interpreter::java_lang_math_cos : break;
case Interpreter::java_lang_math_tan : break;
case Interpreter::java_lang_math_sqrt : break;
case Interpreter::java_lang_math_abs : break;
case Interpreter::java_lang_math_log : break;
case Interpreter::java_lang_math_log10 : break;
default : ShouldNotReachHere(); break;
}
if (entry_point) return entry_point;
return ((InterpreterGenerator*)this)->generate_normal_entry(synchronized);
}
// This method tells the deoptimizer how big an interpreted frame must be:
int AbstractInterpreter::size_activation(methodOop method,
int tempcount,
int popframe_extra_args,
int moncount,
int callee_param_count,
int callee_locals,
bool is_top_frame) {
return layout_activation(method,
tempcount,
popframe_extra_args,
moncount,
callee_param_count,
callee_locals,
(frame*)NULL,
(frame*)NULL,
is_top_frame);
}
void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
// This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
// the days we had adapter frames. When we deoptimize a situation where a
// compiled caller calls a compiled caller will have registers it expects
// to survive the call to the callee. If we deoptimize the callee the only
// way we can restore these registers is to have the oldest interpreter
// frame that we create restore these values. That is what this routine
// will accomplish.
// At the moment we have modified c2 to not have any callee save registers
// so this problem does not exist and this routine is just a place holder.
assert(f->is_interpreted_frame(), "must be interpreted");
}
//----------------------------------------------------------------------------------------------------
// Exceptions