/*
* Copyright (c) 1997, 2010, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "code/debugInfo.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/stackValue.hpp"
StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv) {
if (sv->is_location()) {
// Stack or register value
Location loc = ((LocationValue *)sv)->location();
#ifdef SPARC
// %%%%% Callee-save floats will NOT be working on a Sparc until we
// handle the case of a 2 floats in a single double register.
assert( !(loc.is_register() && loc.type() == Location::float_in_dbl), "Sparc does not handle callee-save floats yet" );
#endif // SPARC
// First find address of value
address value_addr = loc.is_register()
// Value was in a callee-save register
? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()))
// Else value was directly saved on the stack. The frame's original stack pointer,
// before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
: ((address)fr->unextended_sp()) + loc.stack_offset();
// Then package it right depending on type
// Note: the transfer of the data is thru a union that contains
// an intptr_t. This is because an interpreter stack slot is
// really an intptr_t. The use of a union containing an intptr_t
// ensures that on a 64 bit platform we have proper alignment
// and that we store the value where the interpreter will expect
// to find it (i.e. proper endian). Similarly on a 32bit platform
// using the intptr_t ensures that when a value is larger than
// a stack slot (jlong/jdouble) that we capture the proper part
// of the value for the stack slot in question.
//
switch( loc.type() ) {
case Location::float_in_dbl: { // Holds a float in a double register?
// The callee has no clue whether the register holds a float,
// double or is unused. He always saves a double. Here we know
// a double was saved, but we only want a float back. Narrow the
// saved double to the float that the JVM wants.
assert( loc.is_register(), "floats always saved to stack in 1 word" );
union { intptr_t p; jfloat jf; } value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
value.jf = (jfloat) *(jdouble*) value_addr;
return new StackValue(value.p); // 64-bit high half is stack junk
}
case Location::int_in_long: { // Holds an int in a long register?
// The callee has no clue whether the register holds an int,
// long or is unused. He always saves a long. Here we know
// a long was saved, but we only want an int back. Narrow the
// saved long to the int that the JVM wants.
assert( loc.is_register(), "ints always saved to stack in 1 word" );
union { intptr_t p; jint ji;} value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
value.ji = (jint) *(jlong*) value_addr;
return new StackValue(value.p); // 64-bit high half is stack junk
}
#ifdef _LP64
case Location::dbl:
// Double value in an aligned adjacent pair
return new StackValue(*(intptr_t*)value_addr);
case Location::lng:
// Long value in an aligned adjacent pair
return new StackValue(*(intptr_t*)value_addr);
case Location::narrowoop: {
union { intptr_t p; narrowOop noop;} value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
if (loc.is_register()) {
// The callee has no clue whether the register holds an int,
// long or is unused. He always saves a long. Here we know
// a long was saved, but we only want an int back. Narrow the
// saved long to the int that the JVM wants.
value.noop = (narrowOop) *(julong*) value_addr;
} else {
value.noop = *(narrowOop*) value_addr;
}
// Decode narrowoop and wrap a handle around the oop
Handle h(oopDesc::decode_heap_oop(value.noop));
return new StackValue(h);
}
#endif
case Location::oop: {
oop val = *(oop *)value_addr;
#ifdef _LP64
if (Universe::is_narrow_oop_base(val)) {
// Compiled code may produce decoded oop = narrow_oop_base
// when a narrow oop implicit null check is used.
// The narrow_oop_base could be NULL or be the address
// of the page below heap. Use NULL value for both cases.
val = (oop)NULL;
}
#endif
Handle h(val); // Wrap a handle around the oop
return new StackValue(h);
}
case Location::addr: {
ShouldNotReachHere(); // both C1 and C2 now inline jsrs
}
case Location::normal: {
// Just copy all other bits straight through
union { intptr_t p; jint ji;} value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
value.ji = *(jint*)value_addr;
return new StackValue(value.p);
}
case Location::invalid:
return new StackValue();
default:
ShouldNotReachHere();
}
} else if (sv->is_constant_int()) {
// Constant int: treat same as register int.
union { intptr_t p; jint ji;} value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
value.ji = (jint)((ConstantIntValue*)sv)->value();
return new StackValue(value.p);
} else if (sv->is_constant_oop()) {
// constant oop
return new StackValue(((ConstantOopReadValue *)sv)->value());
#ifdef _LP64
} else if (sv->is_constant_double()) {
// Constant double in a single stack slot
union { intptr_t p; double d; } value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
value.d = ((ConstantDoubleValue *)sv)->value();
return new StackValue(value.p);
} else if (sv->is_constant_long()) {
// Constant long in a single stack slot
union { intptr_t p; jlong jl; } value;
value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
value.jl = ((ConstantLongValue *)sv)->value();
return new StackValue(value.p);
#endif
} else if (sv->is_object()) { // Scalar replaced object in compiled frame
Handle ov = ((ObjectValue *)sv)->value();
return new StackValue(ov, (ov.is_null()) ? 1 : 0);
}
// Unknown ScopeValue type
ShouldNotReachHere();
return new StackValue((intptr_t) 0); // dummy
}
BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
assert(location.is_stack(), "for now we only look at the stack");
int word_offset = location.stack_offset() / wordSize;
// (stack picture)
// high: [ ] word_offset + 1
// low [ ] word_offset
//
// sp-> [ ] 0
// the word_offset is the distance from the stack pointer to the lowest address
// The frame's original stack pointer, before any extension by its callee
// (due to Compiler1 linkage on SPARC), must be used.
return (BasicLock*) (fr->unextended_sp() + word_offset);
}
#ifndef PRODUCT
void StackValue::print_on(outputStream* st) const {
switch(_type) {
case T_INT:
st->print("%d (int) %f (float) %x (hex)", *(int *)&_i, *(float *)&_i, *(int *)&_i);
break;
case T_OBJECT:
_o()->print_value_on(st);
st->print(" <" INTPTR_FORMAT ">", (address)_o());
break;
case T_CONFLICT:
st->print("conflict");
break;
default:
ShouldNotReachHere();
}
}
#endif