/*
* Copyright 1997-2006 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.
*
*/
// A frame represents a physical stack frame (an activation). Frames can be
// C or Java frames, and the Java frames can be interpreted or compiled.
// In contrast, vframes represent source-level activations, so that one physical frame
// can correspond to multiple source level frames because of inlining.
// A frame is comprised of {pc, sp, younger_sp}
// Layout of asm interpreter frame:
//
// 0xfffffff
// ......
// [last extra incoming arg, (local # Nargs > 6 ? Nargs-1 : undef)]
// .. Note: incoming args are copied to local frame area upon entry
// [first extra incoming arg, (local # Nargs > 6 ? 6 : undef)]
// [6 words for C-arg storage (unused)] Are this and next one really needed?
// [C-aggregate-word (unused)] Yes, if want extra params to be in same place as C convention
// [16 words for register saving] <--- FP
// [interpreter_frame_vm_locals ] (see below)
// Note: Llocals is always double-word aligned
// [first local i.e. local # 0] <-- Llocals
// ...
// [last local, i.e. local # Nlocals-1]
// [monitors ]
// ....
// [monitors ] <-- Lmonitors (same as Llocals + 6*4 if none)
// (must be double-word aligned because
// monitor element size is constrained to
// doubleword)
//
// <-- Lesp (points 1 past TOS)
// [bottom word used for stack ]
// ...
// [top word used for stack] (first word of stack is double-word aligned)
// [space for outgoing args (conservatively allocated as max_stack - 6 + interpreter_frame_extra_outgoing_argument_words)]
// [6 words for C-arg storage]
// [C-aggregate-word (unused)]
// [16 words for register saving] <--- SP
// ...
// 0x0000000
//
// The in registers and local registers are preserved in a block at SP.
//
// The first six in registers (I0..I5) hold the first six locals.
// The locals are used as follows:
// Lesp first free element of expression stack
// (which grows towards __higher__ addresses)
// Lbcp is set to address of bytecode to execute
// It is accessed in the frame under the name "bcx".
// It may at times (during GC) be an index instead.
// Lmethod the method being interpreted
// Llocals the base pointer for accessing the locals array
// (lower-numbered locals have lower addresses)
// Lmonitors the base pointer for accessing active monitors
// Lcache a saved pointer to the method's constant pool cache
//
//
// When calling out to another method,
// G5_method is set to method to call, G5_inline_cache_klass may be set,
// parameters are put in O registers, and also extra parameters
// must be cleverly copied from the top of stack to the outgoing param area in the frame,
// ------------------------------ C++ interpreter ----------------------------------------
// Layout of C++ interpreter frame:
//
// All frames:
public:
enum {
// normal return address is 2 words past PC
pc_return_offset = 2 * BytesPerInstWord,
// size of each block, in order of increasing address:
register_save_words = 16,
#ifdef _LP64
callee_aggregate_return_pointer_words = 0,
#else
callee_aggregate_return_pointer_words = 1,
#endif
callee_register_argument_save_area_words = 6,
// memory_parameter_words = <arbitrary>,
// offset of each block, in order of increasing address:
// (note: callee_register_argument_save_area_words == Assembler::n_register_parameters)
register_save_words_sp_offset = 0,
callee_aggregate_return_pointer_sp_offset = register_save_words_sp_offset + register_save_words,
callee_register_argument_save_area_sp_offset = callee_aggregate_return_pointer_sp_offset + callee_aggregate_return_pointer_words,
memory_parameter_word_sp_offset = callee_register_argument_save_area_sp_offset + callee_register_argument_save_area_words,
varargs_offset = memory_parameter_word_sp_offset
};
private:
intptr_t* _younger_sp; // optional SP of callee (used to locate O7)
int _sp_adjustment_by_callee; // adjustment in words to SP by callee for making locals contiguous
// Note: On SPARC, unlike Intel, the saved PC for a stack frame
// is stored at a __variable__ distance from that frame's SP.
// (In fact, it may be in the register save area of the callee frame,
// but that fact need not bother us.) Thus, we must store the
// address of that saved PC explicitly. On the other hand, SPARC
// stores the FP for a frame at a fixed offset from the frame's SP,
// so there is no need for a separate "frame::_fp" field.
public:
// Accessors
intptr_t* younger_sp() const {
assert(_younger_sp != NULL, "frame must possess a younger_sp");
return _younger_sp;
}
int callee_sp_adjustment() const { return _sp_adjustment_by_callee; }
void set_sp_adjustment_by_callee(int number_of_words) { _sp_adjustment_by_callee = number_of_words; }
// Constructors
// This constructor relies on the fact that the creator of a frame
// has flushed register windows which the frame will refer to, and
// that those register windows will not be reloaded until the frame is
// done reading and writing the stack. Moreover, if the "younger_sp"
// argument points into the register save area of the next younger
// frame (though it need not), the register window for that next
// younger frame must also stay flushed. (The caller is responsible
// for ensuring this.)
frame(intptr_t* sp, intptr_t* younger_sp, bool younger_frame_adjusted_stack = false);
// make a deficient frame which doesn't know where its PC is:
enum unpatchable_t { unpatchable };
frame(intptr_t* sp, unpatchable_t, address pc = NULL, CodeBlob* cb = NULL);
// Walk from sp outward looking for old_sp, and return old_sp's predecessor
// (i.e. return the sp from the frame where old_sp is the fp).
// Register windows are assumed to be flushed for the stack in question.
static intptr_t* next_younger_sp_or_null(intptr_t* old_sp, intptr_t* sp);
// Return true if sp is a younger sp in the stack described by valid_sp.
static bool is_valid_stack_pointer(intptr_t* valid_sp, intptr_t* sp);
public:
// accessors for the instance variables
intptr_t* fp() const { return (intptr_t*) ((intptr_t)(sp()[FP->sp_offset_in_saved_window()]) + STACK_BIAS ); }
// All frames
intptr_t* fp_addr_at(int index) const { return &fp()[index]; }
intptr_t* sp_addr_at(int index) const { return &sp()[index]; }
intptr_t fp_at( int index) const { return *fp_addr_at(index); }
intptr_t sp_at( int index) const { return *sp_addr_at(index); }
private:
inline address* I7_addr() const;
inline address* O7_addr() const;
inline address* I0_addr() const;
inline address* O0_addr() const;
intptr_t* younger_sp_addr_at(int index) const { return &younger_sp()[index]; }
public:
// access to SPARC arguments and argument registers
// Assumes reg is an in/local register
intptr_t* register_addr(Register reg) const {
return sp_addr_at(reg->sp_offset_in_saved_window());
}
// Assumes reg is an out register
intptr_t* out_register_addr(Register reg) const {
return younger_sp_addr_at(reg->after_save()->sp_offset_in_saved_window());
}
intptr_t* memory_param_addr(int param_ix, bool is_in) const {
int offset = callee_register_argument_save_area_sp_offset + param_ix;
if (is_in)
return fp_addr_at(offset);
else
return sp_addr_at(offset);
}
intptr_t* param_addr(int param_ix, bool is_in) const {
if (param_ix >= callee_register_argument_save_area_words)
return memory_param_addr(param_ix, is_in);
else if (is_in)
return register_addr(Argument(param_ix, true).as_register());
else {
// the registers are stored in the next younger frame
// %%% is this really necessary?
ShouldNotReachHere();
return NULL;
}
}
// Interpreter frames
public:
// Asm interpreter
#ifndef CC_INTERP
enum interpreter_frame_vm_locals {
// 2 words, also used to save float regs across calls to C
interpreter_frame_d_scratch_fp_offset = -2,
interpreter_frame_l_scratch_fp_offset = -4,
interpreter_frame_padding_offset = -5, // for native calls only
interpreter_frame_oop_temp_offset = -6, // for native calls only
interpreter_frame_vm_locals_fp_offset = -6, // should be same as above, and should be zero mod 8
interpreter_frame_vm_local_words = -interpreter_frame_vm_locals_fp_offset,
// interpreter frame set-up needs to save 2 extra words in outgoing param area
// for class and jnienv arguments for native stubs (see nativeStubGen_sparc.cpp_
interpreter_frame_extra_outgoing_argument_words = 2
};
#else
enum interpreter_frame_vm_locals {
// 2 words, also used to save float regs across calls to C
interpreter_state_ptr_offset = 0, // Is in L0 (Lstate) in save area
interpreter_frame_mirror_offset = 1, // Is in L1 (Lmirror) in save area (for native calls only)
// interpreter frame set-up needs to save 2 extra words in outgoing param area
// for class and jnienv arguments for native stubs (see nativeStubGen_sparc.cpp_
interpreter_frame_extra_outgoing_argument_words = 2
};
#endif /* CC_INTERP */
// the compiler frame has many of the same fields as the interpreter frame
// %%%%% factor out declarations of the shared fields
enum compiler_frame_fixed_locals {
compiler_frame_d_scratch_fp_offset = -2,
compiler_frame_vm_locals_fp_offset = -2, // should be same as above
compiler_frame_vm_local_words = -compiler_frame_vm_locals_fp_offset
};
private:
constantPoolCacheOop* frame::interpreter_frame_cpoolcache_addr() const;
#ifndef CC_INTERP
// where Lmonitors is saved:
BasicObjectLock** interpreter_frame_monitors_addr() const {
return (BasicObjectLock**) sp_addr_at(Lmonitors->sp_offset_in_saved_window());
}
intptr_t** interpreter_frame_esp_addr() const {
return (intptr_t**)sp_addr_at(Lesp->sp_offset_in_saved_window());
}
inline void interpreter_frame_set_tos_address(intptr_t* x);
// %%%%% Another idea: instead of defining 3 fns per item, just define one returning a ref
// monitors:
// next two fns read and write Lmonitors value,
private:
BasicObjectLock* interpreter_frame_monitors() const { return *interpreter_frame_monitors_addr(); }
void interpreter_frame_set_monitors(BasicObjectLock* monitors) { *interpreter_frame_monitors_addr() = monitors; }
#else
public:
inline interpreterState get_interpreterState() const {
return ((interpreterState)sp_at(interpreter_state_ptr_offset));
}
#endif /* CC_INTERP */
// Compiled frames
public:
// Tells if this register can hold 64 bits on V9 (really, V8+).
static bool holds_a_doubleword(Register reg) {
#ifdef _LP64
// return true;
return reg->is_out() || reg->is_global();
#else
return reg->is_out() || reg->is_global();
#endif
}