LowLevelInterpreter.asm [plain text]
# Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
# THE POSSIBILITY OF SUCH DAMAGE.
# First come the common protocols that both interpreters use. Note that each
# of these must have an ASSERT() in LLIntData.cpp
# These declarations must match interpreter/RegisterFile.h.
const CallFrameHeaderSize = 48
const ArgumentCount = -48
const CallerFrame = -40
const Callee = -32
const ScopeChain = -24
const ReturnPC = -16
const CodeBlock = -8
const ThisArgumentOffset = -CallFrameHeaderSize - 8
# Some register conventions.
if JSVALUE64
# - Use a pair of registers to represent the PC: one register for the
# base of the register file, and one register for the index.
# - The PC base (or PB for short) should be stored in the csr. It will
# get clobbered on calls to other JS code, but will get saved on calls
# to C functions.
# - C calls are still given the Instruction* rather than the PC index.
# This requires an add before the call, and a sub after.
const PC = t4
const PB = t6
const tagTypeNumber = csr1
const tagMask = csr2
else
const PC = t4
end
# Constants for reasoning about value representation.
if BIG_ENDIAN
const TagOffset = 0
const PayloadOffset = 4
else
const TagOffset = 4
const PayloadOffset = 0
end
# Type constants.
const StringType = 5
const ObjectType = 13
# Type flags constants.
const MasqueradesAsUndefined = 1
const ImplementsHasInstance = 2
const ImplementsDefaultHasInstance = 8
# Bytecode operand constants.
const FirstConstantRegisterIndex = 0x40000000
# Code type constants.
const GlobalCode = 0
const EvalCode = 1
const FunctionCode = 2
# The interpreter steals the tag word of the argument count.
const LLIntReturnPC = ArgumentCount + TagOffset
# String flags.
const HashFlags8BitBuffer = 64
# Allocation constants
if JSVALUE64
const JSFinalObjectSizeClassIndex = 1
else
const JSFinalObjectSizeClassIndex = 3
end
# This must match wtf/Vector.h
if JSVALUE64
const VectorSizeOffset = 0
const VectorBufferOffset = 8
else
const VectorSizeOffset = 0
const VectorBufferOffset = 4
end
# Some common utilities.
macro crash()
storei 0, 0xbbadbeef[]
move 0, t0
call t0
end
macro assert(assertion)
if ASSERT_ENABLED
assertion(.ok)
crash()
.ok:
end
end
macro preserveReturnAddressAfterCall(destinationRegister)
if ARMv7
move lr, destinationRegister
elsif X86 or X86_64
pop destinationRegister
else
error
end
end
macro restoreReturnAddressBeforeReturn(sourceRegister)
if ARMv7
move sourceRegister, lr
elsif X86 or X86_64
push sourceRegister
else
error
end
end
macro traceExecution()
if EXECUTION_TRACING
callSlowPath(_llint_trace)
end
end
macro slowPathForCall(advance, slowPath)
callCallSlowPath(
advance,
slowPath,
macro (callee)
call callee
dispatchAfterCall()
end)
end
macro checkSwitchToJIT(increment, action)
if JIT_ENABLED
loadp CodeBlock[cfr], t0
baddis increment, CodeBlock::m_llintExecuteCounter + ExecutionCounter::m_counter[t0], .continue
action()
.continue:
end
end
macro checkSwitchToJITForEpilogue()
checkSwitchToJIT(
10,
macro ()
callSlowPath(_llint_replace)
end)
end
macro assertNotConstant(index)
assert(macro (ok) bilt index, FirstConstantRegisterIndex, ok end)
end
macro functionForCallCodeBlockGetter(targetRegister)
loadp Callee[cfr], targetRegister
loadp JSFunction::m_executable[targetRegister], targetRegister
loadp FunctionExecutable::m_codeBlockForCall[targetRegister], targetRegister
end
macro functionForConstructCodeBlockGetter(targetRegister)
loadp Callee[cfr], targetRegister
loadp JSFunction::m_executable[targetRegister], targetRegister
loadp FunctionExecutable::m_codeBlockForConstruct[targetRegister], targetRegister
end
macro notFunctionCodeBlockGetter(targetRegister)
loadp CodeBlock[cfr], targetRegister
end
macro functionCodeBlockSetter(sourceRegister)
storep sourceRegister, CodeBlock[cfr]
end
macro notFunctionCodeBlockSetter(sourceRegister)
# Nothing to do!
end
# Do the bare minimum required to execute code. Sets up the PC, leave the CodeBlock*
# in t1. May also trigger prologue entry OSR.
macro prologue(codeBlockGetter, codeBlockSetter, osrSlowPath, traceSlowPath)
preserveReturnAddressAfterCall(t2)
# Set up the call frame and check if we should OSR.
storep t2, ReturnPC[cfr]
if EXECUTION_TRACING
callSlowPath(traceSlowPath)
end
codeBlockGetter(t1)
if JIT_ENABLED
baddis 5, CodeBlock::m_llintExecuteCounter + ExecutionCounter::m_counter[t1], .continue
cCall2(osrSlowPath, cfr, PC)
move t1, cfr
btpz t0, .recover
loadp ReturnPC[cfr], t2
restoreReturnAddressBeforeReturn(t2)
jmp t0
.recover:
codeBlockGetter(t1)
.continue:
end
codeBlockSetter(t1)
# Set up the PC.
if JSVALUE64
loadp CodeBlock::m_instructions[t1], PB
move 0, PC
else
loadp CodeBlock::m_instructions[t1], PC
end
end
# Expects that CodeBlock is in t1, which is what prologue() leaves behind.
# Must call dispatch(0) after calling this.
macro functionInitialization(profileArgSkip)
if VALUE_PROFILER
# Profile the arguments. Unfortunately, we have no choice but to do this. This
# code is pretty horrendous because of the difference in ordering between
# arguments and value profiles, the desire to have a simple loop-down-to-zero
# loop, and the desire to use only three registers so as to preserve the PC and
# the code block. It is likely that this code should be rewritten in a more
# optimal way for architectures that have more than five registers available
# for arbitrary use in the interpreter.
loadi CodeBlock::m_numParameters[t1], t0
addp -profileArgSkip, t0 # Use addi because that's what has the peephole
assert(macro (ok) bpgteq t0, 0, ok end)
btpz t0, .argumentProfileDone
loadp CodeBlock::m_argumentValueProfiles + VectorBufferOffset[t1], t3
mulp sizeof ValueProfile, t0, t2 # Aaaaahhhh! Need strength reduction!
negp t0
lshiftp 3, t0
addp t2, t3
.argumentProfileLoop:
if JSVALUE64
loadp ThisArgumentOffset + 8 - profileArgSkip * 8[cfr, t0], t2
subp sizeof ValueProfile, t3
storep t2, profileArgSkip * sizeof ValueProfile + ValueProfile::m_buckets[t3]
else
loadi ThisArgumentOffset + TagOffset + 8 - profileArgSkip * 8[cfr, t0], t2
subp sizeof ValueProfile, t3
storei t2, profileArgSkip * sizeof ValueProfile + ValueProfile::m_buckets + TagOffset[t3]
loadi ThisArgumentOffset + PayloadOffset + 8 - profileArgSkip * 8[cfr, t0], t2
storei t2, profileArgSkip * sizeof ValueProfile + ValueProfile::m_buckets + PayloadOffset[t3]
end
baddpnz 8, t0, .argumentProfileLoop
.argumentProfileDone:
end
# Check stack height.
loadi CodeBlock::m_numCalleeRegisters[t1], t0
loadp CodeBlock::m_globalData[t1], t2
loadp JSGlobalData::interpreter[t2], t2 # FIXME: Can get to the RegisterFile from the JITStackFrame
lshifti 3, t0
addp t0, cfr, t0
bpaeq Interpreter::m_registerFile + RegisterFile::m_end[t2], t0, .stackHeightOK
# Stack height check failed - need to call a slow_path.
callSlowPath(_llint_register_file_check)
.stackHeightOK:
end
macro allocateBasicJSObject(sizeClassIndex, classInfoOffset, structure, result, scratch1, scratch2, slowCase)
if ALWAYS_ALLOCATE_SLOW
jmp slowCase
else
const offsetOfMySizeClass =
JSGlobalData::heap +
Heap::m_objectSpace +
MarkedSpace::m_normalSpace +
MarkedSpace::Subspace::preciseAllocators +
sizeClassIndex * sizeof MarkedAllocator
const offsetOfFirstFreeCell =
MarkedAllocator::m_freeList +
MarkedBlock::FreeList::head
# FIXME: we can get the global data in one load from the stack.
loadp CodeBlock[cfr], scratch1
loadp CodeBlock::m_globalData[scratch1], scratch1
# Get the object from the free list.
loadp offsetOfMySizeClass + offsetOfFirstFreeCell[scratch1], result
btpz result, slowCase
# Remove the object from the free list.
loadp [result], scratch2
storep scratch2, offsetOfMySizeClass + offsetOfFirstFreeCell[scratch1]
# Initialize the object.
loadp classInfoOffset[scratch1], scratch2
storep scratch2, [result]
storep structure, JSCell::m_structure[result]
storep 0, JSObject::m_inheritorID[result]
addp sizeof JSObject, result, scratch1
storep scratch1, JSObject::m_propertyStorage[result]
end
end
macro doReturn()
loadp ReturnPC[cfr], t2
loadp CallerFrame[cfr], cfr
restoreReturnAddressBeforeReturn(t2)
ret
end
# Indicate the beginning of LLInt.
_llint_begin:
crash()
_llint_program_prologue:
prologue(notFunctionCodeBlockGetter, notFunctionCodeBlockSetter, _llint_entry_osr, _llint_trace_prologue)
dispatch(0)
_llint_eval_prologue:
prologue(notFunctionCodeBlockGetter, notFunctionCodeBlockSetter, _llint_entry_osr, _llint_trace_prologue)
dispatch(0)
_llint_function_for_call_prologue:
prologue(functionForCallCodeBlockGetter, functionCodeBlockSetter, _llint_entry_osr_function_for_call, _llint_trace_prologue_function_for_call)
.functionForCallBegin:
functionInitialization(0)
dispatch(0)
_llint_function_for_construct_prologue:
prologue(functionForConstructCodeBlockGetter, functionCodeBlockSetter, _llint_entry_osr_function_for_construct, _llint_trace_prologue_function_for_construct)
.functionForConstructBegin:
functionInitialization(1)
dispatch(0)
_llint_function_for_call_arity_check:
prologue(functionForCallCodeBlockGetter, functionCodeBlockSetter, _llint_entry_osr_function_for_call_arityCheck, _llint_trace_arityCheck_for_call)
functionArityCheck(.functionForCallBegin, _llint_slow_path_call_arityCheck)
_llint_function_for_construct_arity_check:
prologue(functionForConstructCodeBlockGetter, functionCodeBlockSetter, _llint_entry_osr_function_for_construct_arityCheck, _llint_trace_arityCheck_for_construct)
functionArityCheck(.functionForConstructBegin, _llint_slow_path_construct_arityCheck)
# Value-representation-specific code.
if JSVALUE64
include LowLevelInterpreter64
else
include LowLevelInterpreter32_64
end
# Value-representation-agnostic code.
_llint_op_new_array:
traceExecution()
callSlowPath(_llint_slow_path_new_array)
dispatch(4)
_llint_op_new_array_buffer:
traceExecution()
callSlowPath(_llint_slow_path_new_array_buffer)
dispatch(4)
_llint_op_new_regexp:
traceExecution()
callSlowPath(_llint_slow_path_new_regexp)
dispatch(3)
_llint_op_less:
traceExecution()
callSlowPath(_llint_slow_path_less)
dispatch(4)
_llint_op_lesseq:
traceExecution()
callSlowPath(_llint_slow_path_lesseq)
dispatch(4)
_llint_op_greater:
traceExecution()
callSlowPath(_llint_slow_path_greater)
dispatch(4)
_llint_op_greatereq:
traceExecution()
callSlowPath(_llint_slow_path_greatereq)
dispatch(4)
_llint_op_mod:
traceExecution()
callSlowPath(_llint_slow_path_mod)
dispatch(4)
_llint_op_typeof:
traceExecution()
callSlowPath(_llint_slow_path_typeof)
dispatch(3)
_llint_op_is_object:
traceExecution()
callSlowPath(_llint_slow_path_is_object)
dispatch(3)
_llint_op_is_function:
traceExecution()
callSlowPath(_llint_slow_path_is_function)
dispatch(3)
_llint_op_in:
traceExecution()
callSlowPath(_llint_slow_path_in)
dispatch(4)
_llint_op_resolve:
traceExecution()
callSlowPath(_llint_slow_path_resolve)
dispatch(4)
_llint_op_resolve_skip:
traceExecution()
callSlowPath(_llint_slow_path_resolve_skip)
dispatch(5)
_llint_op_resolve_base:
traceExecution()
callSlowPath(_llint_slow_path_resolve_base)
dispatch(5)
_llint_op_ensure_property_exists:
traceExecution()
callSlowPath(_llint_slow_path_ensure_property_exists)
dispatch(3)
_llint_op_resolve_with_base:
traceExecution()
callSlowPath(_llint_slow_path_resolve_with_base)
dispatch(5)
_llint_op_resolve_with_this:
traceExecution()
callSlowPath(_llint_slow_path_resolve_with_this)
dispatch(5)
_llint_op_del_by_id:
traceExecution()
callSlowPath(_llint_slow_path_del_by_id)
dispatch(4)
_llint_op_del_by_val:
traceExecution()
callSlowPath(_llint_slow_path_del_by_val)
dispatch(4)
_llint_op_put_by_index:
traceExecution()
callSlowPath(_llint_slow_path_put_by_index)
dispatch(4)
_llint_op_put_getter_setter:
traceExecution()
callSlowPath(_llint_slow_path_put_getter_setter)
dispatch(5)
_llint_op_jmp_scopes:
traceExecution()
callSlowPath(_llint_slow_path_jmp_scopes)
dispatch(0)
_llint_op_loop_if_true:
nop
_llint_op_jtrue:
traceExecution()
jumpTrueOrFalse(
macro (value, target) btinz value, target end,
_llint_slow_path_jtrue)
_llint_op_loop_if_false:
nop
_llint_op_jfalse:
traceExecution()
jumpTrueOrFalse(
macro (value, target) btiz value, target end,
_llint_slow_path_jfalse)
_llint_op_loop_if_less:
nop
_llint_op_jless:
traceExecution()
compare(
macro (left, right, target) bilt left, right, target end,
macro (left, right, target) bdlt left, right, target end,
_llint_slow_path_jless)
_llint_op_jnless:
traceExecution()
compare(
macro (left, right, target) bigteq left, right, target end,
macro (left, right, target) bdgtequn left, right, target end,
_llint_slow_path_jnless)
_llint_op_loop_if_greater:
nop
_llint_op_jgreater:
traceExecution()
compare(
macro (left, right, target) bigt left, right, target end,
macro (left, right, target) bdgt left, right, target end,
_llint_slow_path_jgreater)
_llint_op_jngreater:
traceExecution()
compare(
macro (left, right, target) bilteq left, right, target end,
macro (left, right, target) bdltequn left, right, target end,
_llint_slow_path_jngreater)
_llint_op_loop_if_lesseq:
nop
_llint_op_jlesseq:
traceExecution()
compare(
macro (left, right, target) bilteq left, right, target end,
macro (left, right, target) bdlteq left, right, target end,
_llint_slow_path_jlesseq)
_llint_op_jnlesseq:
traceExecution()
compare(
macro (left, right, target) bigt left, right, target end,
macro (left, right, target) bdgtun left, right, target end,
_llint_slow_path_jnlesseq)
_llint_op_loop_if_greatereq:
nop
_llint_op_jgreatereq:
traceExecution()
compare(
macro (left, right, target) bigteq left, right, target end,
macro (left, right, target) bdgteq left, right, target end,
_llint_slow_path_jgreatereq)
_llint_op_jngreatereq:
traceExecution()
compare(
macro (left, right, target) bilt left, right, target end,
macro (left, right, target) bdltun left, right, target end,
_llint_slow_path_jngreatereq)
_llint_op_loop_hint:
traceExecution()
checkSwitchToJITForLoop()
dispatch(1)
_llint_op_switch_string:
traceExecution()
callSlowPath(_llint_slow_path_switch_string)
dispatch(0)
_llint_op_new_func_exp:
traceExecution()
callSlowPath(_llint_slow_path_new_func_exp)
dispatch(3)
_llint_op_call:
traceExecution()
doCall(_llint_slow_path_call)
_llint_op_construct:
traceExecution()
doCall(_llint_slow_path_construct)
_llint_op_call_varargs:
traceExecution()
slowPathForCall(6, _llint_slow_path_call_varargs)
_llint_op_call_eval:
traceExecution()
# Eval is executed in one of two modes:
#
# 1) We find that we're really invoking eval() in which case the
# execution is perfomed entirely inside the slow_path, and it
# returns the PC of a function that just returns the return value
# that the eval returned.
#
# 2) We find that we're invoking something called eval() that is not
# the real eval. Then the slow_path returns the PC of the thing to
# call, and we call it.
#
# This allows us to handle two cases, which would require a total of
# up to four pieces of state that cannot be easily packed into two
# registers (C functions can return up to two registers, easily):
#
# - The call frame register. This may or may not have been modified
# by the slow_path, but the convention is that it returns it. It's not
# totally clear if that's necessary, since the cfr is callee save.
# But that's our style in this here interpreter so we stick with it.
#
# - A bit to say if the slow_path successfully executed the eval and has
# the return value, or did not execute the eval but has a PC for us
# to call.
#
# - Either:
# - The JS return value (two registers), or
#
# - The PC to call.
#
# It turns out to be easier to just always have this return the cfr
# and a PC to call, and that PC may be a dummy thunk that just
# returns the JS value that the eval returned.
slowPathForCall(4, _llint_slow_path_call_eval)
_llint_generic_return_point:
dispatchAfterCall()
_llint_op_strcat:
traceExecution()
callSlowPath(_llint_slow_path_strcat)
dispatch(4)
_llint_op_method_check:
traceExecution()
# We ignore method checks and use normal get_by_id optimizations.
dispatch(1)
_llint_op_get_pnames:
traceExecution()
callSlowPath(_llint_slow_path_get_pnames)
dispatch(0) # The slow_path either advances the PC or jumps us to somewhere else.
_llint_op_push_scope:
traceExecution()
callSlowPath(_llint_slow_path_push_scope)
dispatch(2)
_llint_op_pop_scope:
traceExecution()
callSlowPath(_llint_slow_path_pop_scope)
dispatch(1)
_llint_op_push_new_scope:
traceExecution()
callSlowPath(_llint_slow_path_push_new_scope)
dispatch(4)
_llint_op_throw:
traceExecution()
callSlowPath(_llint_slow_path_throw)
dispatch(2)
_llint_op_throw_reference_error:
traceExecution()
callSlowPath(_llint_slow_path_throw_reference_error)
dispatch(2)
_llint_op_profile_will_call:
traceExecution()
loadp JITStackFrame::enabledProfilerReference[sp], t0
btpz [t0], .opProfileWillCallDone
callSlowPath(_llint_slow_path_profile_will_call)
.opProfileWillCallDone:
dispatch(2)
_llint_op_profile_did_call:
traceExecution()
loadp JITStackFrame::enabledProfilerReference[sp], t0
btpz [t0], .opProfileWillCallDone
callSlowPath(_llint_slow_path_profile_did_call)
.opProfileDidCallDone:
dispatch(2)
_llint_op_debug:
traceExecution()
callSlowPath(_llint_slow_path_debug)
dispatch(4)
_llint_native_call_trampoline:
nativeCallTrampoline(NativeExecutable::m_function)
_llint_native_construct_trampoline:
nativeCallTrampoline(NativeExecutable::m_constructor)
# Lastly, make sure that we can link even though we don't support all opcodes.
# These opcodes should never arise when using LLInt or either JIT. We assert
# as much.
macro notSupported()
if ASSERT_ENABLED
crash()
else
# We should use whatever the smallest possible instruction is, just to
# ensure that there is a gap between instruction labels. If multiple
# smallest instructions exist, we should pick the one that is most
# likely result in execution being halted. Currently that is the break
# instruction on all architectures we're interested in. (Break is int3
# on Intel, which is 1 byte, and bkpt on ARMv7, which is 2 bytes.)
break
end
end
_llint_op_get_array_length:
notSupported()
_llint_op_get_by_id_chain:
notSupported()
_llint_op_get_by_id_custom_chain:
notSupported()
_llint_op_get_by_id_custom_proto:
notSupported()
_llint_op_get_by_id_custom_self:
notSupported()
_llint_op_get_by_id_generic:
notSupported()
_llint_op_get_by_id_getter_chain:
notSupported()
_llint_op_get_by_id_getter_proto:
notSupported()
_llint_op_get_by_id_getter_self:
notSupported()
_llint_op_get_by_id_proto:
notSupported()
_llint_op_get_by_id_self:
notSupported()
_llint_op_get_string_length:
notSupported()
_llint_op_put_by_id_generic:
notSupported()
_llint_op_put_by_id_replace:
notSupported()
_llint_op_put_by_id_transition:
notSupported()
# Indicate the end of LLInt.
_llint_end:
crash()