Merge ivar guards on JIT (#3284)

when an ISeq has multiple ivar accesses.
This commit is contained in:
Takashi Kokubun 2020-07-03 17:52:52 -07:00 committed by GitHub
parent ccb2e6eaa5
commit a69dd699ee
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GPG Key ID: 4AEE18F83AFDEB23
Notes: git 2020-07-04 09:53:18 +09:00
Merged-By: k0kubun <takashikkbn@gmail.com>
2 changed files with 98 additions and 11 deletions

View File

@ -59,6 +59,9 @@ struct compile_status {
int compiled_id; // Just a copy of compiled_iseq->jit_unit->id
// Mutated optimization levels
struct rb_mjit_compile_info *compile_info;
bool merge_ivar_guards_p; // If true, merge guards of ivar accesses
rb_serial_t ivar_serial; // ic_serial of IVC in is_entries (used only when merge_ivar_guards_p)
st_index_t max_ivar_index; // Max IVC index in is_entries (used only when merge_ivar_guards_p)
// If `inlined_iseqs[pos]` is not NULL, `mjit_compile_body` tries to inline ISeq there.
const struct rb_iseq_constant_body **inlined_iseqs;
struct inlined_call_context inline_context;
@ -338,6 +341,20 @@ mjit_compile_body(FILE *f, const rb_iseq_t *iseq, struct compile_status *status)
fprintf(f, " static const VALUE *const original_body_iseq = (VALUE *)0x%"PRIxVALUE";\n",
(VALUE)body->iseq_encoded);
// Generate merged ivar guards first if needed
if (!status->compile_info->disable_ivar_cache && status->merge_ivar_guards_p) {
fprintf(f, " if (UNLIKELY(!(RB_TYPE_P(GET_SELF(), T_OBJECT) && (rb_serial_t)%"PRI_SERIALT_PREFIX"u == RCLASS_SERIAL(RBASIC(GET_SELF())->klass) &&", status->ivar_serial);
if (status->max_ivar_index >= ROBJECT_EMBED_LEN_MAX) {
fprintf(f, "%"PRIuSIZE" < ROBJECT_NUMIV(GET_SELF())", status->max_ivar_index); // index < ROBJECT_NUMIV(obj) && !RB_FL_ANY_RAW(obj, ROBJECT_EMBED)
}
else {
fprintf(f, "ROBJECT_EMBED_LEN_MAX == ROBJECT_NUMIV(GET_SELF())"); // index < ROBJECT_NUMIV(obj) && RB_FL_ANY_RAW(obj, ROBJECT_EMBED)
}
fprintf(f, "))) {\n");
fprintf(f, " goto ivar_cancel;\n");
fprintf(f, " }\n");
}
// Simulate `opt_pc` in setup_parameters_complex. Other PCs which may be passed by catch tables
// are not considered since vm_exec doesn't call mjit_exec for catch tables.
if (body->param.flags.has_opt) {
@ -409,6 +426,45 @@ inlinable_iseq_p(const struct rb_iseq_constant_body *body)
return true;
}
static void
init_ivar_compile_status(const struct rb_iseq_constant_body *body, struct compile_status *status)
{
int num_ivars = 0;
unsigned int pos = 0;
status->max_ivar_index = 0;
status->ivar_serial = 0;
while (pos < body->iseq_size) {
#if OPT_DIRECT_THREADED_CODE || OPT_CALL_THREADED_CODE
int insn = rb_vm_insn_addr2insn((void *)body->iseq_encoded[pos]);
#else
int insn = (int)body->iseq_encoded[pos];
#endif
if (insn == BIN(getinstancevariable) || insn == BIN(setinstancevariable)) {
IVC ic = (IVC)body->iseq_encoded[pos+2];
IVC ic_copy = &(status->is_entries + ((union iseq_inline_storage_entry *)ic - body->is_entries))->iv_cache;
if (ic_copy->ic_serial) { // Only initialized (ic_serial > 0) IVCs are optimized
num_ivars++;
if (status->max_ivar_index < ic_copy->index) {
status->max_ivar_index = ic_copy->index;
}
if (status->ivar_serial == 0) {
status->ivar_serial = ic_copy->ic_serial;
}
else if (status->ivar_serial != ic_copy->ic_serial) {
// Multiple classes have used this ISeq. Give up assuming one serial.
status->merge_ivar_guards_p = false;
return;
}
}
}
pos += insn_len(insn);
}
status->merge_ivar_guards_p = status->ivar_serial > 0 && num_ivars >= 2;
}
// This needs to be macro instead of a function because it's using `alloca`.
#define INIT_COMPILE_STATUS(status, body, compile_root_p) do { \
status = (struct compile_status){ \
@ -476,6 +532,7 @@ precompile_inlinable_iseqs(FILE *f, const rb_iseq_t *iseq, struct compile_status
|| (child_status.is_entries != NULL && !mjit_copy_cache_from_main_thread(child_iseq, child_status.is_entries))) {
return false;
}
init_ivar_compile_status(child_iseq->body, &child_status);
fprintf(f, "ALWAYS_INLINE(static VALUE _mjit%d_inlined_%d(rb_execution_context_t *ec, rb_control_frame_t *reg_cfp, const VALUE orig_self, const rb_iseq_t *original_iseq));\n", status->compiled_id, pos);
fprintf(f, "static inline VALUE\n_mjit%d_inlined_%d(rb_execution_context_t *ec, rb_control_frame_t *reg_cfp, const VALUE orig_self, const rb_iseq_t *original_iseq)\n{\n", status->compiled_id, pos);
@ -503,6 +560,7 @@ mjit_compile(FILE *f, const rb_iseq_t *iseq, const char *funcname, int id)
|| (status.is_entries != NULL && !mjit_copy_cache_from_main_thread(iseq, status.is_entries))) {
return false;
}
init_ivar_compile_status(iseq->body, &status);
if (!status.compile_info->disable_send_cache && !status.compile_info->disable_inlining) {
if (!precompile_inlinable_iseqs(f, iseq, &status))

View File

@ -16,28 +16,57 @@
% # compiler: Use copied IVC to avoid race condition
IVC ic_copy = &(status->is_entries + ((union iseq_inline_storage_entry *)ic - body->is_entries))->iv_cache;
%
if (!status->compile_info->disable_ivar_cache && ic_copy->ic_serial) {
if (!status->compile_info->disable_ivar_cache && ic_copy->ic_serial) { // Only initialized (ic_serial > 0) IVCs are optimized
% # JIT: optimize away motion of sp and pc. This path does not call rb_warning() and so it's always leaf and not `handles_sp`.
% # <%= render 'mjit_compile_pc_and_sp', locals: { insn: insn } -%>
%
% # JIT: prepare vm_getivar/vm_setivar arguments and variables
fprintf(f, "{\n");
fprintf(f, " VALUE obj = GET_SELF();\n");
fprintf(f, " const rb_serial_t ic_serial = (rb_serial_t)%"PRI_SERIALT_PREFIX"u;\n", ic_copy->ic_serial);
fprintf(f, " const st_index_t index = %"PRIuSIZE";\n", ic_copy->index);
fprintf(f, " VALUE val;\n");
if (status->merge_ivar_guards_p) {
% # JIT: Access ivar without checking these VM_ASSERTed prerequisites as we checked them in the beginning of `mjit_compile_body`
fprintf(f, " VM_ASSERT(RB_TYPE_P(obj, T_OBJECT));\n");
fprintf(f, " VM_ASSERT((rb_serial_t)%"PRI_SERIALT_PREFIX"u == RCLASS_SERIAL(RBASIC(obj)->klass));\n", ic_copy->ic_serial);
fprintf(f, " VM_ASSERT(index < ROBJECT_NUMIV(obj));\n");
% if insn.name == 'setinstancevariable'
fprintf(f, " if (LIKELY(!RB_OBJ_FROZEN(obj))) {\n");
fprintf(f, " val = stack[%d];\n", b->stack_size - 1);
if (status->max_ivar_index >= ROBJECT_EMBED_LEN_MAX) {
fprintf(f, " RB_OBJ_WRITE(obj, &ROBJECT(obj)->as.heap.ivptr[index], val);\n");
}
else {
fprintf(f, " RB_OBJ_WRITE(obj, &ROBJECT(obj)->as.ary[index], val);\n");
}
fprintf(f, " }\n");
% else
if (status->max_ivar_index >= ROBJECT_EMBED_LEN_MAX) {
fprintf(f, " val = ROBJECT(obj)->as.heap.ivptr[index];\n");
}
else {
fprintf(f, " val = ROBJECT(obj)->as.ary[index];\n");
}
fprintf(f, " if (LIKELY(val != Qundef)) {\n");
fprintf(f, " stack[%d] = val;\n", b->stack_size);
fprintf(f, " }\n");
%end
}
else {
fprintf(f, " const rb_serial_t ic_serial = (rb_serial_t)%"PRI_SERIALT_PREFIX"u;\n", ic_copy->ic_serial);
% # JIT: cache hit path of vm_getivar/vm_setivar, or cancel JIT (recompile it with exivar)
% if insn.name == 'setinstancevariable'
fprintf(f, " VALUE val = stack[%d];\n", b->stack_size - 1);
fprintf(f, " if (LIKELY(RB_TYPE_P(obj, T_OBJECT) && ic_serial == RCLASS_SERIAL(RBASIC(obj)->klass) && index < ROBJECT_NUMIV(obj) && !RB_OBJ_FROZEN(obj))) {\n");
fprintf(f, " VALUE *ptr = ROBJECT_IVPTR(obj);\n");
fprintf(f, " RB_OBJ_WRITE(obj, &ptr[index], val);\n");
fprintf(f, " }\n");
fprintf(f, " val = stack[%d];\n", b->stack_size - 1);
fprintf(f, " if (LIKELY(RB_TYPE_P(obj, T_OBJECT) && ic_serial == RCLASS_SERIAL(RBASIC(obj)->klass) && index < ROBJECT_NUMIV(obj) && !RB_OBJ_FROZEN(obj))) {\n");
fprintf(f, " VALUE *ptr = ROBJECT_IVPTR(obj);\n");
fprintf(f, " RB_OBJ_WRITE(obj, &ptr[index], val);\n");
fprintf(f, " }\n");
% else
fprintf(f, " VALUE val;\n");
fprintf(f, " if (LIKELY(RB_TYPE_P(obj, T_OBJECT) && ic_serial == RCLASS_SERIAL(RBASIC(obj)->klass) && index < ROBJECT_NUMIV(obj) && (val = ROBJECT_IVPTR(obj)[index]) != Qundef)) {\n");
fprintf(f, " stack[%d] = val;\n", b->stack_size);
fprintf(f, " }\n");
fprintf(f, " if (LIKELY(RB_TYPE_P(obj, T_OBJECT) && ic_serial == RCLASS_SERIAL(RBASIC(obj)->klass) && index < ROBJECT_NUMIV(obj) && (val = ROBJECT_IVPTR(obj)[index]) != Qundef)) {\n");
fprintf(f, " stack[%d] = val;\n", b->stack_size);
fprintf(f, " }\n");
% end
}
fprintf(f, " else {\n");
fprintf(f, " reg_cfp->pc = original_body_iseq + %d;\n", pos);
fprintf(f, " reg_cfp->sp = vm_base_ptr(reg_cfp) + %d;\n", b->stack_size);