1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
ruby--ruby/yjit_codegen.c
Alan Wu 5d834bcf9f YJIT: lazy polymorphic getinstancevariable
Lazily compile out a chain of checks for different known classes and
whether `self` embeds its ivars or not.

* Remove trailing whitespaces

* Get proper addresss in Capstone disassembly

* Lowercase address in Capstone disassembly

Capstone uses lowercase for jump targets in generated listings. Let's
match it.

* Use the same successor in getivar guard chains

Cuts down on duplication

* Address reviews

* Fix copypasta error

* Add a comment
2021-10-20 18:19:31 -04:00

1884 lines
58 KiB
C

#include <assert.h>
#include "insns.inc"
#include "internal.h"
#include "vm_core.h"
#include "vm_sync.h"
#include "vm_callinfo.h"
#include "builtin.h"
#include "internal/compile.h"
#include "internal/class.h"
#include "internal/object.h"
#include "insns_info.inc"
#include "yjit.h"
#include "yjit_iface.h"
#include "yjit_core.h"
#include "yjit_codegen.h"
#include "yjit_asm.h"
#include "yjit_utils.h"
// Map from YARV opcodes to code generation functions
static st_table *gen_fns;
// Code block into which we write machine code
static codeblock_t block;
codeblock_t* cb = NULL;
// Code block into which we write out-of-line machine code
static codeblock_t outline_block;
codeblock_t* ocb = NULL;
// Print the current source location for debugging purposes
RBIMPL_ATTR_MAYBE_UNUSED()
static void
jit_print_loc(jitstate_t* jit, const char* msg)
{
char *ptr;
long len;
VALUE path = rb_iseq_path(jit->iseq);
RSTRING_GETMEM(path, ptr, len);
fprintf(stderr, "%s %s:%u\n", msg, ptr, rb_iseq_line_no(jit->iseq, jit->insn_idx));
}
// Get the current instruction's opcode
static int
jit_get_opcode(jitstate_t* jit)
{
return opcode_at_pc(jit->iseq, jit->pc);
}
// Get the index of the next instruction
static uint32_t
jit_next_idx(jitstate_t* jit)
{
return jit->insn_idx + insn_len(jit_get_opcode(jit));
}
// Get an instruction argument by index
static VALUE
jit_get_arg(jitstate_t* jit, size_t arg_idx)
{
RUBY_ASSERT(arg_idx + 1 < (size_t)insn_len(jit_get_opcode(jit)));
return *(jit->pc + arg_idx + 1);
}
// Load a VALUE into a register and keep track of the reference if it is on the GC heap.
static void
jit_mov_gc_ptr(jitstate_t* jit, codeblock_t* cb, x86opnd_t reg, VALUE ptr)
{
RUBY_ASSERT(reg.type == OPND_REG && reg.num_bits == 64);
// Load the pointer constant into the specified register
mov(cb, reg, const_ptr_opnd((void*)ptr));
// The pointer immediate is encoded as the last part of the mov written out
uint32_t ptr_offset = cb->write_pos - sizeof(VALUE);
if (!SPECIAL_CONST_P(ptr)) {
if (!rb_darray_append(&jit->block->gc_object_offsets, ptr_offset)) {
rb_bug("allocation failed");
}
}
}
// Check if we are compiling the instruction at the stub PC
// Meaning we are compiling the instruction that is next to execute
static bool
jit_at_current_insn(jitstate_t* jit)
{
const VALUE* ec_pc = jit->ec->cfp->pc;
return (ec_pc == jit->pc);
}
// Peek at the topmost value on the Ruby stack
static VALUE
jit_peek_at_stack(jitstate_t* jit, ctx_t* ctx)
{
RUBY_ASSERT(jit_at_current_insn(jit));
VALUE* sp = jit->ec->cfp->sp + ctx->sp_offset;
return *(sp - 1);
}
static VALUE
jit_peek_at_self(jitstate_t *jit, ctx_t *ctx)
{
return jit->ec->cfp->self;
}
// Save YJIT registers prior to a C call
static void
yjit_save_regs(codeblock_t* cb)
{
push(cb, REG_CFP);
push(cb, REG_EC);
push(cb, REG_SP);
push(cb, REG_SP); // Maintain 16-byte RSP alignment
}
// Restore YJIT registers after a C call
static void
yjit_load_regs(codeblock_t* cb)
{
pop(cb, REG_SP); // Maintain 16-byte RSP alignment
pop(cb, REG_SP);
pop(cb, REG_EC);
pop(cb, REG_CFP);
}
/**
Generate an inline exit to return to the interpreter
*/
static void
yjit_gen_exit(jitstate_t* jit, ctx_t* ctx, codeblock_t* cb, VALUE* exit_pc)
{
// Write the adjusted SP back into the CFP
if (ctx->sp_offset != 0)
{
x86opnd_t stack_pointer = ctx_sp_opnd(ctx, 0);
lea(cb, REG_SP, stack_pointer);
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, sp), REG_SP);
}
// Update the CFP on the EC
mov(cb, member_opnd(REG_EC, rb_execution_context_t, cfp), REG_CFP);
// Directly return the next PC, which is a constant
mov(cb, RAX, const_ptr_opnd(exit_pc));
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, pc), RAX);
// Accumulate stats about interpreter exits
#if RUBY_DEBUG
if (rb_yjit_opts.gen_stats) {
mov(cb, RDI, const_ptr_opnd(exit_pc));
call_ptr(cb, RSI, (void *)&rb_yjit_count_side_exit_op);
}
#endif
// Write the post call bytes
cb_write_post_call_bytes(cb);
}
/**
Generate an out-of-line exit to return to the interpreter
*/
static uint8_t *
yjit_side_exit(jitstate_t* jit, ctx_t* ctx)
{
uint8_t* code_ptr = cb_get_ptr(ocb, ocb->write_pos);
// Table mapping opcodes to interpreter handlers
const void * const *handler_table = rb_vm_get_insns_address_table();
// FIXME: rewriting the old instruction is only necessary if we're
// exiting right at an interpreter entry point
// Write back the old instruction at the exit PC
// Otherwise the interpreter may jump right back to the
// JITted code we're trying to exit
VALUE* exit_pc = iseq_pc_at_idx(jit->iseq, jit->insn_idx);
int exit_opcode = opcode_at_pc(jit->iseq, exit_pc);
void* handler_addr = (void*)handler_table[exit_opcode];
mov(ocb, RAX, const_ptr_opnd(exit_pc));
mov(ocb, RCX, const_ptr_opnd(handler_addr));
mov(ocb, mem_opnd(64, RAX, 0), RCX);
// Generate the code to exit to the interpreters
yjit_gen_exit(jit, ctx, ocb, exit_pc);
return code_ptr;
}
#if RUBY_DEBUG
// Increment a profiling counter with counter_name
#define GEN_COUNTER_INC(cb, counter_name) _gen_counter_inc(cb, &(yjit_runtime_counters . counter_name))
static void
_gen_counter_inc(codeblock_t *cb, int64_t *counter)
{
if (!rb_yjit_opts.gen_stats) return;
mov(cb, REG0, const_ptr_opnd(counter));
cb_write_lock_prefix(cb); // for ractors.
add(cb, mem_opnd(64, REG0, 0), imm_opnd(1));
}
// Increment a counter then take an existing side exit.
#define COUNTED_EXIT(side_exit, counter_name) _counted_side_exit(side_exit, &(yjit_runtime_counters . counter_name))
static uint8_t *
_counted_side_exit(uint8_t *existing_side_exit, int64_t *counter)
{
if (!rb_yjit_opts.gen_stats) return existing_side_exit;
uint8_t *start = cb_get_ptr(ocb, ocb->write_pos);
_gen_counter_inc(ocb, counter);
jmp_ptr(ocb, existing_side_exit);
return start;
}
#else
#define GEN_COUNTER_INC(cb, counter_name) ((void)0)
#define COUNTED_EXIT(side_exit, counter_name) side_exit
#endif // if RUBY_DEBUG
/*
Compile an interpreter entry block to be inserted into an iseq
Returns `NULL` if compilation fails.
*/
uint8_t*
yjit_entry_prologue(void)
{
RUBY_ASSERT(cb != NULL);
if (cb->write_pos + 1024 >= cb->mem_size) {
rb_bug("out of executable memory");
}
// Align the current write positon to cache line boundaries
cb_align_pos(cb, 64);
uint8_t *code_ptr = cb_get_ptr(cb, cb->write_pos);
// Write the interpreter entry prologue
cb_write_pre_call_bytes(cb);
// Load the current SP from the CFP into REG_SP
mov(cb, REG_SP, member_opnd(REG_CFP, rb_control_frame_t, sp));
return code_ptr;
}
/*
Generate code to check for interrupts and take a side-exit
*/
static void
yjit_check_ints(codeblock_t* cb, uint8_t* side_exit)
{
// Check for interrupts
// see RUBY_VM_CHECK_INTS(ec) macro
mov(cb, REG0_32, member_opnd(REG_EC, rb_execution_context_t, interrupt_mask));
not(cb, REG0_32);
test(cb, member_opnd(REG_EC, rb_execution_context_t, interrupt_flag), REG0_32);
jnz_ptr(cb, side_exit);
}
/*
Compile a sequence of bytecode instructions for a given basic block version
*/
void
yjit_gen_block(ctx_t* ctx, block_t* block, rb_execution_context_t* ec)
{
RUBY_ASSERT(cb != NULL);
RUBY_ASSERT(block != NULL);
const rb_iseq_t *iseq = block->blockid.iseq;
uint32_t insn_idx = block->blockid.idx;
// NOTE: if we are ever deployed in production, we
// should probably just log an error and return NULL here,
// so we can fail more gracefully
if (cb->write_pos + 1024 >= cb->mem_size) {
rb_bug("out of executable memory");
}
if (ocb->write_pos + 1024 >= ocb->mem_size) {
rb_bug("out of executable memory (outlined block)");
}
// Initialize a JIT state object
jitstate_t jit = {
block,
iseq,
0,
0,
ec
};
// Mark the start position of the block
block->start_pos = cb->write_pos;
// For each instruction to compile
for (;;) {
// Set the current instruction
jit.insn_idx = insn_idx;
jit.pc = iseq_pc_at_idx(iseq, insn_idx);
// Get the current opcode
int opcode = jit_get_opcode(&jit);
// Lookup the codegen function for this instruction
codegen_fn gen_fn;
if (!rb_st_lookup(gen_fns, opcode, (st_data_t*)&gen_fn)) {
// If we reach an unknown instruction,
// exit to the interpreter and stop compiling
yjit_gen_exit(&jit, ctx, cb, jit.pc);
break;
}
//fprintf(stderr, "compiling %d: %s\n", insn_idx, insn_name(opcode));
//print_str(cb, insn_name(opcode));
// Count bytecode instructions that execute in generated code
// FIXME: when generation function returns false, we shouldn't increment
// this counter.
GEN_COUNTER_INC(cb, exec_instruction);
// Call the code generation function
bool continue_generating = p_desc->gen_fn(&jit, ctx);
// For now, reset the chain depth after each instruction
ctx->chain_depth = 0;
// If we can't compile this instruction
// exit to the interpreter and stop compiling
if (status == YJIT_CANT_COMPILE) {
yjit_gen_exit(&jit, ctx, cb, jit.pc);
break;
}
// Move to the next instruction
p_last_op = p_desc;
insn_idx += insn_len(opcode);
// If the instruction terminates this block
if (status == YJIT_END_BLOCK) {
break;
}
}
// Mark the end position of the block
block->end_pos = cb->write_pos;
// Store the index of the last instruction in the block
block->end_idx = insn_idx;
if (YJIT_DUMP_MODE >= 2) {
// Dump list of compiled instrutions
fprintf(stderr, "Compiled the following for iseq=%p:\n", (void *)iseq);
for (uint32_t idx = block->blockid.idx; idx < insn_idx;)
{
int opcode = opcode_at_pc(iseq, iseq_pc_at_idx(iseq, idx));
fprintf(stderr, " %04d %s\n", idx, insn_name(opcode));
idx += insn_len(opcode);
}
}
}
static codegen_status_t
gen_dup(jitstate_t* jit, ctx_t* ctx)
{
// Get the top value and its type
x86opnd_t dup_val = ctx_stack_pop(ctx, 0);
int dup_type = ctx_get_top_type(ctx);
// Push the same value on top
x86opnd_t loc0 = ctx_stack_push(ctx, dup_type);
mov(cb, REG0, dup_val);
mov(cb, loc0, REG0);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_nop(jitstate_t* jit, ctx_t* ctx)
{
// Do nothing
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_pop(jitstate_t* jit, ctx_t* ctx)
{
// Decrement SP
ctx_stack_pop(ctx, 1);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_putnil(jitstate_t* jit, ctx_t* ctx)
{
// Write constant at SP
x86opnd_t stack_top = ctx_stack_push(ctx, T_NIL);
mov(cb, stack_top, imm_opnd(Qnil));
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_putobject(jitstate_t* jit, ctx_t* ctx)
{
VALUE arg = jit_get_arg(jit, 0);
if (FIXNUM_P(arg))
{
// Keep track of the fixnum type tag
x86opnd_t stack_top = ctx_stack_push(ctx, T_FIXNUM);
x86opnd_t imm = imm_opnd((int64_t)arg);
// 64-bit immediates can't be directly written to memory
if (imm.num_bits <= 32)
{
mov(cb, stack_top, imm);
}
else
{
mov(cb, REG0, imm);
mov(cb, stack_top, REG0);
}
}
else if (arg == Qtrue || arg == Qfalse)
{
x86opnd_t stack_top = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_top, imm_opnd((int64_t)arg));
}
else
{
// Load the argument from the bytecode sequence.
// We need to do this as the argument can change due to GC compaction.
x86opnd_t pc_plus_one = const_ptr_opnd((void*)(jit->pc + 1));
mov(cb, RAX, pc_plus_one);
mov(cb, RAX, mem_opnd(64, RAX, 0));
// Write argument at SP
x86opnd_t stack_top = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_top, RAX);
}
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_putobject_int2fix(jitstate_t* jit, ctx_t* ctx)
{
int opcode = jit_get_opcode(jit);
int cst_val = (opcode == BIN(putobject_INT2FIX_0_))? 0:1;
// Write constant at SP
x86opnd_t stack_top = ctx_stack_push(ctx, T_FIXNUM);
mov(cb, stack_top, imm_opnd(INT2FIX(cst_val)));
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_putself(jitstate_t* jit, ctx_t* ctx)
{
// Load self from CFP
mov(cb, RAX, member_opnd(REG_CFP, rb_control_frame_t, self));
// Write it on the stack
x86opnd_t stack_top = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_top, RAX);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_getlocal_wc0(jitstate_t* jit, ctx_t* ctx)
{
// Load environment pointer EP from CFP
mov(cb, REG0, member_opnd(REG_CFP, rb_control_frame_t, ep));
// Compute the offset from BP to the local
int32_t local_idx = (int32_t)jit_get_arg(jit, 0);
const int32_t offs = -(SIZEOF_VALUE * local_idx);
// Load the local from the block
mov(cb, REG0, mem_opnd(64, REG0, offs));
// Write the local at SP
x86opnd_t stack_top = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_top, REG0);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_getlocal_wc1(jitstate_t* jit, ctx_t* ctx)
{
//fprintf(stderr, "gen_getlocal_wc1\n");
// Load environment pointer EP from CFP
mov(cb, REG0, member_opnd(REG_CFP, rb_control_frame_t, ep));
// Get the previous EP from the current EP
// See GET_PREV_EP(ep) macro
// VALUE* prev_ep = ((VALUE *)((ep)[VM_ENV_DATA_INDEX_SPECVAL] & ~0x03))
mov(cb, REG0, mem_opnd(64, REG0, SIZEOF_VALUE * VM_ENV_DATA_INDEX_SPECVAL));
and(cb, REG0, imm_opnd(~0x03));
// Load the local from the block
// val = *(vm_get_ep(GET_EP(), level) - idx);
int32_t local_idx = (int32_t)jit_get_arg(jit, 0);
const int32_t offs = -(SIZEOF_VALUE * local_idx);
mov(cb, REG0, mem_opnd(64, REG0, offs));
// Write the local at SP
x86opnd_t stack_top = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_top, REG0);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_setlocal_wc0(jitstate_t* jit, ctx_t* ctx)
{
/*
vm_env_write(const VALUE *ep, int index, VALUE v)
{
VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS];
if (LIKELY((flags & VM_ENV_FLAG_WB_REQUIRED) == 0)) {
VM_STACK_ENV_WRITE(ep, index, v);
}
else {
vm_env_write_slowpath(ep, index, v);
}
}
*/
// Load environment pointer EP from CFP
mov(cb, REG0, member_opnd(REG_CFP, rb_control_frame_t, ep));
// flags & VM_ENV_FLAG_WB_REQUIRED
x86opnd_t flags_opnd = mem_opnd(64, REG0, sizeof(VALUE) * VM_ENV_DATA_INDEX_FLAGS);
test(cb, flags_opnd, imm_opnd(VM_ENV_FLAG_WB_REQUIRED));
// Create a size-exit to fall back to the interpreter
uint8_t* side_exit = yjit_side_exit(jit, ctx);
// if (flags & VM_ENV_FLAG_WB_REQUIRED) != 0
jnz_ptr(cb, side_exit);
// Pop the value to write from the stack
x86opnd_t stack_top = ctx_stack_pop(ctx, 1);
mov(cb, REG1, stack_top);
// Write the value at the environment pointer
int32_t local_idx = (int32_t)jit_get_arg(jit, 0);
const int32_t offs = -8 * local_idx;
mov(cb, mem_opnd(64, REG0, offs), REG1);
return YJIT_KEEP_COMPILING;
}
// Check that `self` is a pointer to an object on the GC heap
static void
guard_self_is_object(codeblock_t *cb, x86opnd_t self_opnd, uint8_t *side_exit, ctx_t *ctx)
{
// `self` is constant throughout the entire region, so we only need to do this check once.
if (!ctx->self_is_object) {
test(cb, self_opnd, imm_opnd(RUBY_IMMEDIATE_MASK));
jnz_ptr(cb, side_exit);
cmp(cb, self_opnd, imm_opnd(Qfalse));
je_ptr(cb, side_exit);
cmp(cb, self_opnd, imm_opnd(Qnil));
je_ptr(cb, side_exit);
// maybe we can do
// RUBY_ASSERT(Qfalse < Qnil);
// cmp(cb, self_opnd, imm_opnd(Qnil));
// jbe(cb, side_exit);
ctx->self_is_object = true;
}
}
static void
gen_jnz_to_target0(codeblock_t *cb, uint8_t *target0, uint8_t *target1, uint8_t shape)
{
switch (shape)
{
case SHAPE_NEXT0:
case SHAPE_NEXT1:
RUBY_ASSERT(false);
break;
case SHAPE_DEFAULT:
jnz_ptr(cb, target0);
break;
}
}
static void
gen_jz_to_target0(codeblock_t *cb, uint8_t *target0, uint8_t *target1, uint8_t shape)
{
switch (shape)
{
case SHAPE_NEXT0:
case SHAPE_NEXT1:
RUBY_ASSERT(false);
break;
case SHAPE_DEFAULT:
jz_ptr(cb, target0);
break;
}
}
enum jcc_kinds {
JCC_JNE,
JCC_JNZ,
JCC_JZ,
JCC_JE,
};
// Generate a jump to a stub that recompiles the current YARV instruction on failure.
// When depth_limitk is exceeded, generate a jump to a side exit.
static void
jit_chain_guard(enum jcc_kinds jcc, jitstate_t *jit, ctx_t *ctx, uint8_t depth_limit, uint8_t *side_exit)
{
branchgen_fn target0_gen_fn;
switch (jcc) {
case JCC_JNE:
case JCC_JNZ:
target0_gen_fn = gen_jnz_to_target0;
break;
case JCC_JZ:
case JCC_JE:
target0_gen_fn = gen_jz_to_target0;
break;
default:
RUBY_ASSERT(false && "unimplemented jump kind");
break;
};
if (ctx->chain_depth < depth_limit) {
ctx_t deeper = *ctx;
deeper.chain_depth++;
gen_branch(
ctx,
(blockid_t) { jit->iseq, jit->insn_idx },
&deeper,
BLOCKID_NULL,
NULL,
target0_gen_fn
);
}
else {
target0_gen_fn(cb, side_exit, NULL, SHAPE_DEFAULT);
}
}
bool rb_iv_index_tbl_lookup(struct st_table *iv_index_tbl, ID id, struct rb_iv_index_tbl_entry **ent); // vm_insnhelper.c
enum {
GETIVAR_MAX_DEPTH = 10 // up to 5 different classes, and embedded or not for each
};
static codegen_status_t
gen_getinstancevariable(jitstate_t* jit, ctx_t* ctx)
{
// Defer compilation so we can specialize a runtime `self`
if (!jit_at_current_insn(jit)) {
defer_compilation(jit->block, jit->insn_idx, ctx);
return YJIT_END_BLOCK;
}
// Specialize base on the compile time self
VALUE self_val = jit_peek_at_self(jit, ctx);
VALUE self_klass = rb_class_of(self_val);
// Create a size-exit to fall back to the interpreter
uint8_t *side_exit = yjit_side_exit(jit, ctx);
// If the class uses the default allocator, instances should all be T_OBJECT
// NOTE: This assumes nobody changes the allocator of the class after allocation.
// Eventually, we can encode whether an object is T_OBJECT or not
// inside object shapes.
if (rb_get_alloc_func(self_klass) != rb_class_allocate_instance) {
jmp_ptr(cb, side_exit);
return YJIT_END_BLOCK;
}
RUBY_ASSERT(BUILTIN_TYPE(self_val) == T_OBJECT); // because we checked the allocator
ID id = (ID)jit_get_arg(jit, 0);
struct rb_iv_index_tbl_entry *ent;
struct st_table *iv_index_tbl = ROBJECT_IV_INDEX_TBL(self_val);
// Lookup index for the ivar the instruction loads
if (iv_index_tbl && rb_iv_index_tbl_lookup(iv_index_tbl, id, &ent)) {
uint32_t ivar_index = ent->index;
// Load self from CFP
mov(cb, REG0, member_opnd(REG_CFP, rb_control_frame_t, self));
guard_self_is_object(cb, REG0, COUNTED_EXIT(side_exit, getivar_se_self_not_heap), ctx);
// Guard that self has a known class
x86opnd_t klass_opnd = mem_opnd(64, REG0, offsetof(struct RBasic, klass));
mov(cb, REG1, klass_opnd);
x86opnd_t serial_opnd = mem_opnd(64, REG1, offsetof(struct RClass, class_serial));
cmp(cb, serial_opnd, imm_opnd(RCLASS_SERIAL(self_klass)));
jit_chain_guard(JCC_JNE, jit, ctx, GETIVAR_MAX_DEPTH, side_exit);
// Compile time self is embedded and the ivar index is within the object
if (RB_FL_TEST_RAW(self_val, ROBJECT_EMBED) && ivar_index < ROBJECT_EMBED_LEN_MAX) {
// See ROBJECT_IVPTR() from include/ruby/internal/core/robject.h
// Guard that self is embedded
// TODO: BT and JC is shorter
x86opnd_t flags_opnd = member_opnd(REG0, struct RBasic, flags);
test(cb, flags_opnd, imm_opnd(ROBJECT_EMBED));
jit_chain_guard(JCC_JZ, jit, ctx, GETIVAR_MAX_DEPTH, side_exit);
// Load the variable
x86opnd_t ivar_opnd = mem_opnd(64, REG0, offsetof(struct RObject, as.ary) + ivar_index * SIZEOF_VALUE);
mov(cb, REG1, ivar_opnd);
// Guard that the variable is not Qundef
cmp(cb, REG1, imm_opnd(Qundef));
je_ptr(cb, COUNTED_EXIT(side_exit, getivar_undef));
// Push the ivar on the stack
x86opnd_t out_opnd = ctx_stack_push(ctx, T_NONE);
mov(cb, out_opnd, REG1);
}
else {
// Compile time self is *not* embeded.
// Guard that self is *not* embedded
// See ROBJECT_IVPTR() from include/ruby/internal/core/robject.h
x86opnd_t flags_opnd = member_opnd(REG0, struct RBasic, flags);
test(cb, flags_opnd, imm_opnd(ROBJECT_EMBED));
jit_chain_guard(JCC_JNZ, jit, ctx, GETIVAR_MAX_DEPTH, side_exit);
// check that the extended table is big enough
if (ivar_index >= ROBJECT_EMBED_LEN_MAX + 1) {
// Check that the slot is inside the extended table (num_slots > index)
x86opnd_t num_slots = mem_opnd(32, REG0, offsetof(struct RObject, as.heap.numiv));
cmp(cb, num_slots, imm_opnd(ivar_index));
jle_ptr(cb, COUNTED_EXIT(side_exit, getivar_idx_out_of_range));
}
// Get a pointer to the extended table
x86opnd_t tbl_opnd = mem_opnd(64, REG0, offsetof(struct RObject, as.heap.ivptr));
mov(cb, REG0, tbl_opnd);
// Read the ivar from the extended table
x86opnd_t ivar_opnd = mem_opnd(64, REG0, sizeof(VALUE) * ivar_index);
mov(cb, REG0, ivar_opnd);
// Check that the ivar is not Qundef
cmp(cb, REG0, imm_opnd(Qundef));
je_ptr(cb, COUNTED_EXIT(side_exit, getivar_undef));
// Push the ivar on the stack
x86opnd_t out_opnd = ctx_stack_push(ctx, T_NONE);
mov(cb, out_opnd, REG0);
}
// Jump to next instruction. This allows guard chains to share the same successor.
{
ctx_t reset_depth = *ctx;
reset_depth.chain_depth = 0;
blockid_t jump_block = { jit->iseq, jit_next_insn_idx(jit) };
// Generate the jump instruction
gen_direct_jump(
&reset_depth,
jump_block
);
}
return YJIT_END_BLOCK;
}
// Take side exit because YJIT_CANT_COMPILE can exit to a JIT entry point and
// form an infinite loop when chain_depth > 0.
jmp_ptr(cb, side_exit);
return YJIT_END_BLOCK;
}
static codegen_status_t
gen_setinstancevariable(jitstate_t* jit, ctx_t* ctx)
{
IVC ic = (IVC)jit_get_arg(jit, 1);
// Check that the inline cache has been set, slot index is known
if (!ic->entry) {
return YJIT_CANT_COMPILE;
}
// If the class uses the default allocator, instances should all be T_OBJECT
// NOTE: This assumes nobody changes the allocator of the class after allocation.
// Eventually, we can encode whether an object is T_OBJECT or not
// inside object shapes.
if (rb_get_alloc_func(ic->entry->class_value) != rb_class_allocate_instance) {
return YJIT_CANT_COMPILE;
}
uint32_t ivar_index = ic->entry->index;
// Create a size-exit to fall back to the interpreter
uint8_t* side_exit = yjit_side_exit(jit, ctx);
// Load self from CFP
mov(cb, REG0, member_opnd(REG_CFP, rb_control_frame_t, self));
guard_self_is_object(cb, REG0, side_exit, ctx);
// Bail if receiver class is different from compiled time call cache class
x86opnd_t klass_opnd = mem_opnd(64, REG0, offsetof(struct RBasic, klass));
mov(cb, REG1, klass_opnd);
x86opnd_t serial_opnd = mem_opnd(64, REG1, offsetof(struct RClass, class_serial));
cmp(cb, serial_opnd, imm_opnd(ic->entry->class_serial));
jne_ptr(cb, side_exit);
// Bail if the ivars are not on the extended table
// See ROBJECT_IVPTR() from include/ruby/internal/core/robject.h
x86opnd_t flags_opnd = member_opnd(REG0, struct RBasic, flags);
test(cb, flags_opnd, imm_opnd(ROBJECT_EMBED));
jnz_ptr(cb, side_exit);
// If we can't guarantee that the extended table is big enoughg
if (ivar_index >= ROBJECT_EMBED_LEN_MAX + 1) {
// Check that the slot is inside the extended table (num_slots > index)
x86opnd_t num_slots = mem_opnd(32, REG0, offsetof(struct RObject, as.heap.numiv));
cmp(cb, num_slots, imm_opnd(ivar_index));
jle_ptr(cb, side_exit);
}
// Get a pointer to the extended table
x86opnd_t tbl_opnd = mem_opnd(64, REG0, offsetof(struct RObject, as.heap.ivptr));
mov(cb, REG0, tbl_opnd);
// Pop the value to write from the stack
x86opnd_t stack_top = ctx_stack_pop(ctx, 1);
mov(cb, REG1, stack_top);
// Bail if this is a heap object, because this needs a write barrier
test(cb, REG1, imm_opnd(RUBY_IMMEDIATE_MASK));
jz_ptr(cb, side_exit);
// Write the ivar to the extended table
x86opnd_t ivar_opnd = mem_opnd(64, REG0, sizeof(VALUE) * ivar_index);
mov(cb, ivar_opnd, REG1);
return YJIT_KEEP_COMPILING;
}
// Conditional move operation used by comparison operators
typedef void (*cmov_fn)(codeblock_t* cb, x86opnd_t opnd0, x86opnd_t opnd1);
static codegen_status_t
gen_fixnum_cmp(jitstate_t* jit, ctx_t* ctx, cmov_fn cmov_op)
{
// Create a size-exit to fall back to the interpreter
// Note: we generate the side-exit before popping operands from the stack
uint8_t* side_exit = yjit_side_exit(jit, ctx);
if (!assume_bop_not_redefined(jit->block, INTEGER_REDEFINED_OP_FLAG, BOP_LT)) {
return YJIT_CANT_COMPILE;
}
// Get the operands and destination from the stack
int arg1_type = ctx_get_top_type(ctx);
x86opnd_t arg1 = ctx_stack_pop(ctx, 1);
int arg0_type = ctx_get_top_type(ctx);
x86opnd_t arg0 = ctx_stack_pop(ctx, 1);
// If not fixnums, fall back
if (arg0_type != T_FIXNUM) {
test(cb, arg0, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
}
if (arg1_type != T_FIXNUM) {
test(cb, arg1, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
}
// Compare the arguments
xor(cb, REG0_32, REG0_32); // REG0 = Qfalse
mov(cb, REG1, arg0);
cmp(cb, REG1, arg1);
mov(cb, REG1, imm_opnd(Qtrue));
cmov_op(cb, REG0, REG1);
// Push the output on the stack
x86opnd_t dst = ctx_stack_push(ctx, T_NONE);
mov(cb, dst, REG0);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_opt_lt(jitstate_t* jit, ctx_t* ctx)
{
return gen_fixnum_cmp(jit, ctx, cmovl);
}
static codegen_status_t
gen_opt_le(jitstate_t* jit, ctx_t* ctx)
{
return gen_fixnum_cmp(jit, ctx, cmovle);
}
static codegen_status_t
gen_opt_ge(jitstate_t* jit, ctx_t* ctx)
{
return gen_fixnum_cmp(jit, ctx, cmovge);
}
static codegen_status_t
gen_opt_aref(jitstate_t* jit, ctx_t* ctx)
{
struct rb_call_data * cd = (struct rb_call_data *)jit_get_arg(jit, 0);
int32_t argc = (int32_t)vm_ci_argc(cd->ci);
// Only JIT one arg calls like `ary[6]`
if (argc != 1) {
return YJIT_CANT_COMPILE;
}
const rb_callable_method_entry_t *cme = vm_cc_cme(cd->cc);
// Bail if the inline cache has been filled. Currently, certain types
// (including arrays) don't use the inline cache, so if the inline cache
// has an entry, then this must be used by some other type.
if (cme) {
return YJIT_CANT_COMPILE;
}
// Create a size-exit to fall back to the interpreter
uint8_t* side_exit = yjit_side_exit(jit, ctx);
if (!assume_bop_not_redefined(jit->block, ARRAY_REDEFINED_OP_FLAG, BOP_AREF)) {
return YJIT_CANT_COMPILE;
}
// Pop the stack operands
x86opnd_t idx_opnd = ctx_stack_pop(ctx, 1);
x86opnd_t recv_opnd = ctx_stack_pop(ctx, 1);
mov(cb, REG0, recv_opnd);
// if (SPECIAL_CONST_P(recv)) {
// Bail if it's not a heap object
test(cb, REG0, imm_opnd(RUBY_IMMEDIATE_MASK));
jnz_ptr(cb, side_exit);
cmp(cb, REG0, imm_opnd(Qfalse));
je_ptr(cb, side_exit);
cmp(cb, REG0, imm_opnd(Qnil));
je_ptr(cb, side_exit);
// Bail if recv has a class other than ::Array.
// BOP_AREF check above is only good for ::Array.
mov(cb, REG1, mem_opnd(64, REG0, offsetof(struct RBasic, klass)));
mov(cb, REG0, const_ptr_opnd((void *)rb_cArray));
cmp(cb, REG0, REG1);
jne_ptr(cb, side_exit);
// Bail if idx is not a FIXNUM
mov(cb, REG1, idx_opnd);
test(cb, REG1, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
// Save YJIT registers
yjit_save_regs(cb);
mov(cb, RDI, recv_opnd);
sar(cb, REG1, imm_opnd(1)); // Convert fixnum to int
mov(cb, RSI, REG1);
call_ptr(cb, REG0, (void *)rb_ary_entry_internal);
// Restore YJIT registers
yjit_load_regs(cb);
x86opnd_t stack_ret = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_ret, RAX);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_opt_and(jitstate_t* jit, ctx_t* ctx)
{
// Create a size-exit to fall back to the interpreter
// Note: we generate the side-exit before popping operands from the stack
uint8_t* side_exit = yjit_side_exit(jit, ctx);
if (!assume_bop_not_redefined(jit->block, INTEGER_REDEFINED_OP_FLAG, BOP_AND)) {
return YJIT_CANT_COMPILE;
}
// Get the operands and destination from the stack
int arg1_type = ctx_get_top_type(ctx);
x86opnd_t arg1 = ctx_stack_pop(ctx, 1);
int arg0_type = ctx_get_top_type(ctx);
x86opnd_t arg0 = ctx_stack_pop(ctx, 1);
// If not fixnums, fall back
if (arg0_type != T_FIXNUM) {
test(cb, arg0, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
}
if (arg1_type != T_FIXNUM) {
test(cb, arg1, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
}
// Do the bitwise and arg0 & arg1
mov(cb, REG0, arg0);
and(cb, REG0, arg1);
// Push the output on the stack
x86opnd_t dst = ctx_stack_push(ctx, T_FIXNUM);
mov(cb, dst, REG0);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_opt_minus(jitstate_t* jit, ctx_t* ctx)
{
// Create a size-exit to fall back to the interpreter
// Note: we generate the side-exit before popping operands from the stack
uint8_t* side_exit = yjit_side_exit(jit, ctx);
if (!assume_bop_not_redefined(jit->block, INTEGER_REDEFINED_OP_FLAG, BOP_MINUS)) {
return YJIT_CANT_COMPILE;
}
// Get the operands and destination from the stack
x86opnd_t arg1 = ctx_stack_pop(ctx, 1);
x86opnd_t arg0 = ctx_stack_pop(ctx, 1);
// If not fixnums, fall back
test(cb, arg0, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
test(cb, arg1, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
// Subtract arg0 - arg1 and test for overflow
mov(cb, REG0, arg0);
sub(cb, REG0, arg1);
jo_ptr(cb, side_exit);
add(cb, REG0, imm_opnd(1));
// Push the output on the stack
x86opnd_t dst = ctx_stack_push(ctx, T_FIXNUM);
mov(cb, dst, REG0);
return YJIT_KEEP_COMPILING;
}
static codegen_status_t
gen_opt_plus(jitstate_t* jit, ctx_t* ctx)
{
// Create a size-exit to fall back to the interpreter
// Note: we generate the side-exit before popping operands from the stack
uint8_t* side_exit = yjit_side_exit(jit, ctx);
if (!assume_bop_not_redefined(jit->block, INTEGER_REDEFINED_OP_FLAG, BOP_PLUS)) {
return YJIT_CANT_COMPILE;
}
// Get the operands and destination from the stack
int arg1_type = ctx_get_top_type(ctx);
x86opnd_t arg1 = ctx_stack_pop(ctx, 1);
int arg0_type = ctx_get_top_type(ctx);
x86opnd_t arg0 = ctx_stack_pop(ctx, 1);
// If not fixnums, fall back
if (arg0_type != T_FIXNUM) {
test(cb, arg0, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
}
if (arg1_type != T_FIXNUM) {
test(cb, arg1, imm_opnd(RUBY_FIXNUM_FLAG));
jz_ptr(cb, side_exit);
}
// Add arg0 + arg1 and test for overflow
mov(cb, REG0, arg0);
sub(cb, REG0, imm_opnd(1));
add(cb, REG0, arg1);
jo_ptr(cb, side_exit);
// Push the output on the stack
x86opnd_t dst = ctx_stack_push(ctx, T_FIXNUM);
mov(cb, dst, REG0);
return YJIT_KEEP_COMPILING;
}
void
gen_branchif_branch(codeblock_t* cb, uint8_t* target0, uint8_t* target1, uint8_t shape)
{
switch (shape)
{
case SHAPE_NEXT0:
jz_ptr(cb, target1);
break;
case SHAPE_NEXT1:
jnz_ptr(cb, target0);
break;
case SHAPE_DEFAULT:
jnz_ptr(cb, target0);
jmp_ptr(cb, target1);
break;
}
}
static codegen_status_t
gen_branchif(jitstate_t* jit, ctx_t* ctx)
{
// FIXME: eventually, put VM_CHECK_INTS() only on backward branch targets
// Check for interrupts
uint8_t* side_exit = yjit_side_exit(jit, ctx);
yjit_check_ints(cb, side_exit);
// Test if any bit (outside of the Qnil bit) is on
// RUBY_Qfalse /* ...0000 0000 */
// RUBY_Qnil /* ...0000 1000 */
x86opnd_t val_opnd = ctx_stack_pop(ctx, 1);
test(cb, val_opnd, imm_opnd(~Qnil));
// Get the branch target instruction offsets
uint32_t next_idx = jit_next_idx(jit);
uint32_t jump_idx = next_idx + (uint32_t)jit_get_arg(jit, 0);
blockid_t next_block = { jit->iseq, next_idx };
blockid_t jump_block = { jit->iseq, jump_idx };
// Generate the branch instructions
gen_branch(
ctx,
jump_block,
ctx,
next_block,
ctx,
gen_branchif_branch
);
return YJIT_END_BLOCK;
}
void
gen_branchunless_branch(codeblock_t* cb, uint8_t* target0, uint8_t* target1, uint8_t shape)
{
switch (shape)
{
case SHAPE_NEXT0:
jnz_ptr(cb, target1);
break;
case SHAPE_NEXT1:
jz_ptr(cb, target0);
break;
case SHAPE_DEFAULT:
jz_ptr(cb, target0);
jmp_ptr(cb, target1);
break;
}
}
static codegen_status_t
gen_branchunless(jitstate_t* jit, ctx_t* ctx)
{
// FIXME: eventually, put VM_CHECK_INTS() only on backward branch targets
// Check for interrupts
uint8_t* side_exit = yjit_side_exit(jit, ctx);
yjit_check_ints(cb, side_exit);
// Test if any bit (outside of the Qnil bit) is on
// RUBY_Qfalse /* ...0000 0000 */
// RUBY_Qnil /* ...0000 1000 */
x86opnd_t val_opnd = ctx_stack_pop(ctx, 1);
test(cb, val_opnd, imm_opnd(~Qnil));
// Get the branch target instruction offsets
uint32_t next_idx = jit_next_idx(jit);
uint32_t jump_idx = next_idx + (uint32_t)jit_get_arg(jit, 0);
blockid_t next_block = { jit->iseq, next_idx };
blockid_t jump_block = { jit->iseq, jump_idx };
// Generate the branch instructions
gen_branch(
ctx,
jump_block,
ctx,
next_block,
ctx,
gen_branchunless_branch
);
return YJIT_END_BLOCK;
}
static codegen_status_t
gen_jump(jitstate_t* jit, ctx_t* ctx)
{
// FIXME: eventually, put VM_CHECK_INTS() only on backward branch targets
// Check for interrupts
uint8_t* side_exit = yjit_side_exit(jit, ctx);
yjit_check_ints(cb, side_exit);
// Get the branch target instruction offsets
uint32_t jump_idx = jit_next_idx(jit) + (int32_t)jit_get_arg(jit, 0);
blockid_t jump_block = { jit->iseq, jump_idx };
// Generate the jump instruction
gen_direct_jump(
ctx,
jump_block
);
return YJIT_END_BLOCK;
}
static void
jit_protected_guard(jitstate_t *jit, codeblock_t *cb, const rb_callable_method_entry_t *cme, uint8_t *side_exit)
{
// Callee is protected. Generate ancestry guard.
// See vm_call_method().
yjit_save_regs(cb);
mov(cb, C_ARG_REGS[0], member_opnd(REG_CFP, rb_control_frame_t, self));
jit_mov_gc_ptr(jit, cb, C_ARG_REGS[1], cme->defined_class);
// Note: PC isn't written to current control frame as rb_is_kind_of() shouldn't raise.
// VALUE rb_obj_is_kind_of(VALUE obj, VALUE klass);
call_ptr(cb, REG0, (void *)&rb_obj_is_kind_of);
yjit_load_regs(cb);
test(cb, RAX, RAX);
jz_ptr(cb, COUNTED_EXIT(side_exit, oswb_se_protected_check_failed));
}
static bool
gen_oswb_cfunc(jitstate_t* jit, ctx_t* ctx, struct rb_call_data * cd, const rb_callable_method_entry_t *cme, int32_t argc)
{
const rb_method_cfunc_t *cfunc = UNALIGNED_MEMBER_PTR(cme->def, body.cfunc);
// If the function expects a Ruby array of arguments
if (cfunc->argc < 0 && cfunc->argc != -1)
{
GEN_COUNTER_INC(cb, oswb_cfunc_ruby_array_varg);
return YJIT_CANT_COMPILE;
}
// If the argument count doesn't match
if (cfunc->argc >= 0 && cfunc->argc != argc)
{
GEN_COUNTER_INC(cb, oswb_cfunc_argc_mismatch);
return YJIT_CANT_COMPILE;
}
// Don't JIT functions that need C stack arguments for now
if (argc + 1 > NUM_C_ARG_REGS) {
GEN_COUNTER_INC(cb, oswb_cfunc_toomany_args);
return YJIT_CANT_COMPILE;
}
// Create a size-exit to fall back to the interpreter
uint8_t *side_exit = yjit_side_exit(jit, ctx);
// Check for interrupts
yjit_check_ints(cb, side_exit);
// Points to the receiver operand on the stack
x86opnd_t recv = ctx_stack_opnd(ctx, argc);
mov(cb, REG0, recv);
// Callee method ID
//ID mid = vm_ci_mid(cd->ci);
//printf("JITting call to C function \"%s\", argc: %lu\n", rb_id2name(mid), argc);
//print_str(cb, "");
//print_str(cb, "calling CFUNC:");
//print_str(cb, rb_id2name(mid));
//print_str(cb, "recv");
//print_ptr(cb, recv);
// Check that the receiver is a heap object
{
uint8_t *receiver_not_heap = COUNTED_EXIT(side_exit, oswb_se_receiver_not_heap);
test(cb, REG0, imm_opnd(RUBY_IMMEDIATE_MASK));
jnz_ptr(cb, receiver_not_heap);
cmp(cb, REG0, imm_opnd(Qfalse));
je_ptr(cb, receiver_not_heap);
cmp(cb, REG0, imm_opnd(Qnil));
je_ptr(cb, receiver_not_heap);
}
// Pointer to the klass field of the receiver &(recv->klass)
x86opnd_t klass_opnd = mem_opnd(64, REG0, offsetof(struct RBasic, klass));
// FIXME: This leaks when st_insert raises NoMemoryError
assume_method_lookup_stable(cd->cc, cme, jit->block);
// Bail if receiver class is different from compile-time call cache class
jit_mov_gc_ptr(jit, cb, REG1, (VALUE)cd->cc->klass);
cmp(cb, klass_opnd, REG1);
jne_ptr(cb, COUNTED_EXIT(side_exit, oswb_se_cc_klass_differ));
// Store incremented PC into current control frame in case callee raises.
mov(cb, REG0, const_ptr_opnd(jit->pc + insn_len(BIN(opt_send_without_block))));
mov(cb, mem_opnd(64, REG_CFP, offsetof(rb_control_frame_t, pc)), REG0);
if (METHOD_ENTRY_VISI(cme) == METHOD_VISI_PROTECTED) {
// Generate ancestry guard for protected callee.
jit_protected_guard(jit, cb, cme, side_exit);
}
// If this function needs a Ruby stack frame
if (cfunc_needs_frame(cfunc))
{
// Stack overflow check
// #define CHECK_VM_STACK_OVERFLOW0(cfp, sp, margin)
// REG_CFP <= REG_SP + 4 * sizeof(VALUE) + sizeof(rb_control_frame_t)
lea(cb, REG0, ctx_sp_opnd(ctx, sizeof(VALUE) * 4 + sizeof(rb_control_frame_t)));
cmp(cb, REG_CFP, REG0);
jle_ptr(cb, COUNTED_EXIT(side_exit, oswb_se_cf_overflow));
// Increment the stack pointer by 3 (in the callee)
// sp += 3
lea(cb, REG0, ctx_sp_opnd(ctx, sizeof(VALUE) * 3));
// Put compile time cme into REG1. It's assumed to be valid because we are notified when
// any cme we depend on become outdated. See rb_yjit_method_lookup_change().
jit_mov_gc_ptr(jit, cb, REG1, (VALUE)cme);
// Write method entry at sp[-3]
// sp[-3] = me;
mov(cb, mem_opnd(64, REG0, 8 * -3), REG1);
// Write block handler at sp[-2]
// sp[-2] = block_handler;
mov(cb, mem_opnd(64, REG0, 8 * -2), imm_opnd(VM_BLOCK_HANDLER_NONE));
// Write env flags at sp[-1]
// sp[-1] = frame_type;
uint64_t frame_type = VM_FRAME_MAGIC_CFUNC | VM_FRAME_FLAG_CFRAME | VM_ENV_FLAG_LOCAL;
mov(cb, mem_opnd(64, REG0, 8 * -1), imm_opnd(frame_type));
// Allocate a new CFP (ec->cfp--)
sub(
cb,
member_opnd(REG_EC, rb_execution_context_t, cfp),
imm_opnd(sizeof(rb_control_frame_t))
);
// Setup the new frame
// *cfp = (const struct rb_control_frame_struct) {
// .pc = 0,
// .sp = sp,
// .iseq = 0,
// .self = recv,
// .ep = sp - 1,
// .block_code = 0,
// .__bp__ = sp,
// };
mov(cb, REG1, member_opnd(REG_EC, rb_execution_context_t, cfp));
mov(cb, member_opnd(REG1, rb_control_frame_t, pc), imm_opnd(0));
mov(cb, member_opnd(REG1, rb_control_frame_t, sp), REG0);
mov(cb, member_opnd(REG1, rb_control_frame_t, iseq), imm_opnd(0));
mov(cb, member_opnd(REG1, rb_control_frame_t, block_code), imm_opnd(0));
mov(cb, member_opnd(REG1, rb_control_frame_t, __bp__), REG0);
sub(cb, REG0, imm_opnd(sizeof(VALUE)));
mov(cb, member_opnd(REG1, rb_control_frame_t, ep), REG0);
mov(cb, REG0, recv);
mov(cb, member_opnd(REG1, rb_control_frame_t, self), REG0);
}
// Verify that we are calling the right function
if (YJIT_CHECK_MODE > 0) {
// Save YJIT registers
yjit_save_regs(cb);
// Call check_cfunc_dispatch
mov(cb, RDI, recv);
jit_mov_gc_ptr(jit, cb, RSI, (VALUE)cd);
mov(cb, RDX, const_ptr_opnd((void *)cfunc->func));
jit_mov_gc_ptr(jit, cb, RCX, (VALUE)cme);
call_ptr(cb, REG0, (void *)&check_cfunc_dispatch);
// Load YJIT registers
yjit_load_regs(cb);
}
// Save YJIT registers
yjit_save_regs(cb);
// Copy SP into RAX because REG_SP will get overwritten
lea(cb, RAX, ctx_sp_opnd(ctx, 0));
// Non-variadic method
if (cfunc->argc >= 0)
{
// Copy the arguments from the stack to the C argument registers
// self is the 0th argument and is at index argc from the stack top
for (int32_t i = 0; i < argc + 1; ++i)
{
x86opnd_t stack_opnd = mem_opnd(64, RAX, -(argc + 1 - i) * SIZEOF_VALUE);
x86opnd_t c_arg_reg = C_ARG_REGS[i];
mov(cb, c_arg_reg, stack_opnd);
}
}
// Variadic method
if (cfunc->argc == -1)
{
// The method gets a pointer to the first argument
// rb_f_puts(int argc, VALUE *argv, VALUE recv)
mov(cb, C_ARG_REGS[0], imm_opnd(argc));
lea(cb, C_ARG_REGS[1], mem_opnd(64, RAX, -(argc) * SIZEOF_VALUE));
mov(cb, C_ARG_REGS[2], mem_opnd(64, RAX, -(argc + 1) * SIZEOF_VALUE));
}
// Pop the C function arguments from the stack (in the caller)
ctx_stack_pop(ctx, argc + 1);
// Call the C function
// VALUE ret = (cfunc->func)(recv, argv[0], argv[1]);
// cfunc comes from compile-time cme->def, which we assume to be stable.
// Invalidation logic is in rb_yjit_method_lookup_change()
call_ptr(cb, REG0, (void*)cfunc->func);
// Load YJIT registers
yjit_load_regs(cb);
// Push the return value on the Ruby stack
x86opnd_t stack_ret = ctx_stack_push(ctx, T_NONE);
mov(cb, stack_ret, RAX);
// If this function needs a Ruby stack frame
if (cfunc_needs_frame(cfunc))
{
// Pop the stack frame (ec->cfp++)
add(
cb,
member_opnd(REG_EC, rb_execution_context_t, cfp),
imm_opnd(sizeof(rb_control_frame_t))
);
}
// Jump (fall through) to the call continuation block
// We do this to end the current block after the call
blockid_t cont_block = { jit->iseq, jit_next_idx(jit) };
gen_direct_jump(
ctx,
cont_block
);
return YJIT_END_BLOCK;
}
bool rb_simple_iseq_p(const rb_iseq_t *iseq);
static void
gen_return_branch(codeblock_t* cb, uint8_t* target0, uint8_t* target1, uint8_t shape)
{
switch (shape)
{
case SHAPE_NEXT0:
case SHAPE_NEXT1:
RUBY_ASSERT(false);
break;
case SHAPE_DEFAULT:
mov(cb, REG0, const_ptr_opnd(target0));
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, jit_return), REG0);
break;
}
}
static codegen_status_t
gen_oswb_iseq(jitstate_t* jit, ctx_t* ctx, struct rb_call_data * cd, const rb_callable_method_entry_t *cme, int32_t argc)
{
const rb_iseq_t *iseq = def_iseq_ptr(cme->def);
const VALUE* start_pc = iseq->body->iseq_encoded;
int num_params = iseq->body->param.size;
int num_locals = iseq->body->local_table_size - num_params;
if (num_params != argc) {
GEN_COUNTER_INC(cb, oswb_iseq_argc_mismatch);
return YJIT_CANT_COMPILE;
}
if (!rb_simple_iseq_p(iseq)) {
// Only handle iseqs that have simple parameters.
// See vm_callee_setup_arg().
GEN_COUNTER_INC(cb, oswb_iseq_not_simple);
return YJIT_CANT_COMPILE;
}
if (vm_ci_flag(cd->ci) & VM_CALL_TAILCALL) {
// We can't handle tailcalls
GEN_COUNTER_INC(cb, oswb_iseq_tailcall);
return YJIT_CANT_COMPILE;
}
// Create a size-exit to fall back to the interpreter
uint8_t* side_exit = yjit_side_exit(jit, ctx);
// Check for interrupts
yjit_check_ints(cb, side_exit);
// Points to the receiver operand on the stack
x86opnd_t recv = ctx_stack_opnd(ctx, argc);
mov(cb, REG0, recv);
// Callee method ID
//ID mid = vm_ci_mid(cd->ci);
//printf("JITting call to Ruby function \"%s\", argc: %d\n", rb_id2name(mid), argc);
//print_str(cb, "");
//print_str(cb, "recv");
//print_ptr(cb, recv);
// Check that the receiver is a heap object
{
uint8_t *receiver_not_heap = COUNTED_EXIT(side_exit, oswb_se_receiver_not_heap);
test(cb, REG0, imm_opnd(RUBY_IMMEDIATE_MASK));
jnz_ptr(cb, receiver_not_heap);
cmp(cb, REG0, imm_opnd(Qfalse));
je_ptr(cb, receiver_not_heap);
cmp(cb, REG0, imm_opnd(Qnil));
je_ptr(cb, receiver_not_heap);
}
// Pointer to the klass field of the receiver &(recv->klass)
x86opnd_t klass_opnd = mem_opnd(64, REG0, offsetof(struct RBasic, klass));
assume_method_lookup_stable(cd->cc, cme, jit->block);
// Bail if receiver class is different from compile-time call cache class
jit_mov_gc_ptr(jit, cb, REG1, (VALUE)cd->cc->klass);
cmp(cb, klass_opnd, REG1);
jne_ptr(cb, COUNTED_EXIT(side_exit, oswb_se_cc_klass_differ));
if (METHOD_ENTRY_VISI(cme) == METHOD_VISI_PROTECTED) {
// Generate ancestry guard for protected callee.
jit_protected_guard(jit, cb, cme, side_exit);
}
// Store the updated SP on the current frame (pop arguments and receiver)
lea(cb, REG0, ctx_sp_opnd(ctx, sizeof(VALUE) * -(argc + 1)));
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, sp), REG0);
// Store the next PC i the current frame
mov(cb, REG0, const_ptr_opnd(jit->pc + insn_len(BIN(opt_send_without_block))));
mov(cb, mem_opnd(64, REG_CFP, offsetof(rb_control_frame_t, pc)), REG0);
// Stack overflow check
// #define CHECK_VM_STACK_OVERFLOW0(cfp, sp, margin)
lea(cb, REG0, ctx_sp_opnd(ctx, sizeof(VALUE) * (num_locals + iseq->body->stack_max) + sizeof(rb_control_frame_t)));
cmp(cb, REG_CFP, REG0);
jle_ptr(cb, COUNTED_EXIT(side_exit, oswb_se_cf_overflow));
// Adjust the callee's stack pointer
lea(cb, REG0, ctx_sp_opnd(ctx, sizeof(VALUE) * (3 + num_locals)));
// Initialize local variables to Qnil
for (int i = 0; i < num_locals; i++) {
mov(cb, mem_opnd(64, REG0, sizeof(VALUE) * (i - num_locals - 3)), imm_opnd(Qnil));
}
// Put compile time cme into REG1. It's assumed to be valid because we are notified when
// any cme we depend on become outdated. See rb_yjit_method_lookup_change().
jit_mov_gc_ptr(jit, cb, REG1, (VALUE)cme);
// Write method entry at sp[-3]
// sp[-3] = me;
mov(cb, mem_opnd(64, REG0, 8 * -3), REG1);
// Write block handler at sp[-2]
// sp[-2] = block_handler;
mov(cb, mem_opnd(64, REG0, 8 * -2), imm_opnd(VM_BLOCK_HANDLER_NONE));
// Write env flags at sp[-1]
// sp[-1] = frame_type;
uint64_t frame_type = VM_FRAME_MAGIC_METHOD | VM_ENV_FLAG_LOCAL;
mov(cb, mem_opnd(64, REG0, 8 * -1), imm_opnd(frame_type));
// Allocate a new CFP (ec->cfp--)
sub(cb, REG_CFP, imm_opnd(sizeof(rb_control_frame_t)));
mov(cb, member_opnd(REG_EC, rb_execution_context_t, cfp), REG_CFP);
// Setup the new frame
// *cfp = (const struct rb_control_frame_struct) {
// .pc = pc,
// .sp = sp,
// .iseq = iseq,
// .self = recv,
// .ep = sp - 1,
// .block_code = 0,
// .__bp__ = sp,
// };
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, block_code), imm_opnd(0));
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, sp), REG0);
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, __bp__), REG0);
sub(cb, REG0, imm_opnd(sizeof(VALUE)));
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, ep), REG0);
mov(cb, REG0, recv);
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, self), REG0);
jit_mov_gc_ptr(jit, cb, REG0, (VALUE)iseq);
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, iseq), REG0);
mov(cb, REG0, const_ptr_opnd(start_pc));
mov(cb, member_opnd(REG_CFP, rb_control_frame_t, pc), REG0);
// Stub so we can return to JITted code
blockid_t return_block = { jit->iseq, jit_next_insn_idx(jit) };
// Pop arguments and receiver in return context, push the return value
// After the return, the JIT and interpreter SP will match up
ctx_t return_ctx = *ctx;
ctx_stack_pop(&return_ctx, argc + 1);
ctx_stack_push(&return_ctx, T_NONE);
return_ctx.sp_offset = 0;
// Write the JIT return address on the callee frame
gen_branch(
ctx,
return_block,
&return_ctx,
return_block,
&return_ctx,
gen_return_branch
);
//print_str(cb, "calling Ruby func:");
//print_str(cb, rb_id2name(vm_ci_mid(cd->ci)));
// Load the updated SP
mov(cb, REG_SP, member_opnd(REG_CFP, rb_control_frame_t, sp));
// Directly jump to the entry point of the callee
gen_direct_jump(
&DEFAULT_CTX,
(blockid_t){ iseq, 0 }
);
return true;
}
static codegen_status_t
gen_opt_send_without_block(jitstate_t* jit, ctx_t* ctx)
{
// Relevant definitions:
// rb_execution_context_t : vm_core.h
// invoker, cfunc logic : method.h, vm_method.c
// rb_callable_method_entry_t : method.h
// vm_call_cfunc_with_frame : vm_insnhelper.c
// rb_callcache : vm_callinfo.h
struct rb_call_data * cd = (struct rb_call_data *)jit_get_arg(jit, 0);
int32_t argc = (int32_t)vm_ci_argc(cd->ci);
// Don't JIT calls with keyword splat
if (vm_ci_flag(cd->ci) & VM_CALL_KW_SPLAT) {
GEN_COUNTER_INC(cb, oswb_kw_splat);
return YJIT_CANT_COMPILE;
}
// Don't JIT calls that aren't simple
if (!(vm_ci_flag(cd->ci) & VM_CALL_ARGS_SIMPLE)) {
GEN_COUNTER_INC(cb, oswb_callsite_not_simple);
return YJIT_CANT_COMPILE;
}
// Don't JIT if the inline cache is not set
if (!cd->cc || !cd->cc->klass) {
GEN_COUNTER_INC(cb, oswb_ic_empty);
return YJIT_CANT_COMPILE;
}
const rb_callable_method_entry_t *cme = vm_cc_cme(cd->cc);
// Don't JIT if the method entry is out of date
if (METHOD_ENTRY_INVALIDATED(cme)) {
GEN_COUNTER_INC(cb, oswb_invalid_cme);
return YJIT_CANT_COMPILE;
}
switch (cme->def->type) {
case VM_METHOD_TYPE_ISEQ:
return gen_oswb_iseq(jit, ctx, cd, cme, argc);
case VM_METHOD_TYPE_CFUNC:
return gen_oswb_cfunc(jit, ctx, cd, cme, argc);
case VM_METHOD_TYPE_ATTRSET:
GEN_COUNTER_INC(cb, oswb_ivar_set_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_BMETHOD:
GEN_COUNTER_INC(cb, oswb_bmethod);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_IVAR:
GEN_COUNTER_INC(cb, oswb_ivar_get_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_ZSUPER:
GEN_COUNTER_INC(cb, oswb_zsuper_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_ALIAS:
GEN_COUNTER_INC(cb, oswb_alias_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_UNDEF:
GEN_COUNTER_INC(cb, oswb_undef_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_NOTIMPLEMENTED:
GEN_COUNTER_INC(cb, oswb_not_implemented_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_OPTIMIZED:
GEN_COUNTER_INC(cb, oswb_optimized_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_MISSING:
GEN_COUNTER_INC(cb, oswb_missing_method);
return YJIT_CANT_COMPILE;
case VM_METHOD_TYPE_REFINED:
GEN_COUNTER_INC(cb, oswb_refined_method);
return YJIT_CANT_COMPILE;
// no default case so compiler issues a warning if this is not exhaustive
}
}
static codegen_status_t
gen_leave(jitstate_t* jit, ctx_t* ctx)
{
// Only the return value should be on the stack
RUBY_ASSERT(ctx->stack_size == 1);
// Create a size-exit to fall back to the interpreter
uint8_t* side_exit = yjit_side_exit(jit, ctx);
// Load environment pointer EP from CFP
mov(cb, REG0, member_opnd(REG_CFP, rb_control_frame_t, ep));
// if (flags & VM_FRAME_FLAG_FINISH) != 0
x86opnd_t flags_opnd = mem_opnd(64, REG0, sizeof(VALUE) * VM_ENV_DATA_INDEX_FLAGS);
test(cb, flags_opnd, imm_opnd(VM_FRAME_FLAG_FINISH));
jnz_ptr(cb, COUNTED_EXIT(side_exit, leave_se_finish_frame));
// Check for interrupts
yjit_check_ints(cb, COUNTED_EXIT(side_exit, leave_se_interrupt));
// Load the return value
mov(cb, REG0, ctx_stack_pop(ctx, 1));
// Load the JIT return address
mov(cb, REG1, member_opnd(REG_CFP, rb_control_frame_t, jit_return));
// Pop the current frame (ec->cfp++)
// Note: the return PC is already in the previous CFP
add(cb, REG_CFP, imm_opnd(sizeof(rb_control_frame_t)));
mov(cb, member_opnd(REG_EC, rb_execution_context_t, cfp), REG_CFP);
// Push the return value on the caller frame
// The SP points one above the topmost value
add(cb, member_opnd(REG_CFP, rb_control_frame_t, sp), imm_opnd(SIZEOF_VALUE));
mov(cb, REG_SP, member_opnd(REG_CFP, rb_control_frame_t, sp));
mov(cb, mem_opnd(64, REG_SP, -SIZEOF_VALUE), REG0);
// If the return address is NULL, fall back to the interpreter
int FALLBACK_LABEL = cb_new_label(cb, "FALLBACK");
test(cb, REG1, REG1);
jz_label(cb, FALLBACK_LABEL);
// Jump to the JIT return address
jmp_rm(cb, REG1);
// Fall back to the interpreter
cb_write_label(cb, FALLBACK_LABEL);
cb_link_labels(cb);
cb_write_post_call_bytes(cb);
return YJIT_END_BLOCK;
}
RUBY_EXTERN rb_serial_t ruby_vm_global_constant_state;
static codegen_status_t
gen_opt_getinlinecache(jitstate_t *jit, ctx_t *ctx)
{
VALUE jump_offset = jit_get_arg(jit, 0);
VALUE const_cache_as_value = jit_get_arg(jit, 1);
IC ic = (IC)const_cache_as_value;
// See vm_ic_hit_p().
struct iseq_inline_constant_cache_entry *ice = ic->entry;
if (!ice) {
// Cache not filled
return YJIT_CANT_COMPILE;
}
if (ice->ic_serial != ruby_vm_global_constant_state) {
// Cache miss at compile time.
return YJIT_CANT_COMPILE;
}
if (ice->ic_cref) {
// Only compile for caches that don't care about lexical scope.
return YJIT_CANT_COMPILE;
}
// Optimize for single ractor mode.
// FIXME: This leaks when st_insert raises NoMemoryError
if (!assume_single_ractor_mode(jit->block)) return YJIT_CANT_COMPILE;
// Invalidate output code on any and all constant writes
// FIXME: This leaks when st_insert raises NoMemoryError
if (!assume_stable_global_constant_state(jit->block)) return YJIT_CANT_COMPILE;
x86opnd_t stack_top = ctx_stack_push(ctx, T_NONE);
jit_mov_gc_ptr(jit, cb, REG0, ice->value);
mov(cb, stack_top, REG0);
// Jump over the code for filling the cache
uint32_t jump_idx = jit_next_insn_idx(jit) + (int32_t)jump_offset;
gen_direct_jump(
ctx,
(blockid_t){ .iseq = jit->iseq, .idx = jump_idx }
);
return YJIT_END_BLOCK;
}
void yjit_reg_op(int opcode, codegen_fn gen_fn)
{
// Check that the op wasn't previously registered
st_data_t st_gen;
if (rb_st_lookup(gen_fns, opcode, &st_gen)) {
rb_bug("op already registered");
}
st_insert(gen_fns, (st_data_t)opcode, (st_data_t)gen_fn);
}
void
yjit_init_codegen(void)
{
// Initialize the code blocks
uint32_t mem_size = 128 * 1024 * 1024;
uint8_t* mem_block = alloc_exec_mem(mem_size);
cb = &block;
cb_init(cb, mem_block, mem_size/2);
ocb = &outline_block;
cb_init(ocb, mem_block + mem_size/2, mem_size/2);
// Initialize the codegen function table
gen_fns = rb_st_init_numtable();
// Map YARV opcodes to the corresponding codegen functions
yjit_reg_op(BIN(dup), gen_dup);
yjit_reg_op(BIN(nop), gen_nop);
yjit_reg_op(BIN(pop), gen_pop);
yjit_reg_op(BIN(putnil), gen_putnil);
yjit_reg_op(BIN(putobject), gen_putobject);
yjit_reg_op(BIN(putobject_INT2FIX_0_), gen_putobject_int2fix);
yjit_reg_op(BIN(putobject_INT2FIX_1_), gen_putobject_int2fix);
yjit_reg_op(BIN(putself), gen_putself);
yjit_reg_op(BIN(getlocal_WC_0), gen_getlocal_wc0);
yjit_reg_op(BIN(getlocal_WC_1), gen_getlocal_wc1);
yjit_reg_op(BIN(setlocal_WC_0), gen_setlocal_wc0);
yjit_reg_op(BIN(getinstancevariable), gen_getinstancevariable);
yjit_reg_op(BIN(setinstancevariable), gen_setinstancevariable);
yjit_reg_op(BIN(opt_lt), gen_opt_lt);
yjit_reg_op(BIN(opt_le), gen_opt_le);
yjit_reg_op(BIN(opt_ge), gen_opt_ge);
yjit_reg_op(BIN(opt_aref), gen_opt_aref);
yjit_reg_op(BIN(opt_and), gen_opt_and);
yjit_reg_op(BIN(opt_minus), gen_opt_minus);
yjit_reg_op(BIN(opt_plus), gen_opt_plus);
// Map branch instruction opcodes to codegen functions
yjit_reg_op(BIN(opt_getinlinecache), gen_opt_getinlinecache);
yjit_reg_op(BIN(branchif), gen_branchif);
yjit_reg_op(BIN(branchunless), gen_branchunless);
yjit_reg_op(BIN(jump), gen_jump);
yjit_reg_op(BIN(opt_send_without_block), gen_opt_send_without_block);
yjit_reg_op(BIN(leave), gen_leave);
}