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refactor in preparation for cse
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@Fidget-Spinner
Fidget-Spinner committed Dec 12, 2023
1 parent 43d8e51 commit 4bbe03f
Showing 1 changed file with 98 additions and 76 deletions.
174 changes: 98 additions & 76 deletions Python/optimizer_analysis.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1248,9 +1248,17 @@ uop_abstract_interpret(
return NULL;
}

typedef struct _Py_UOpsEmitter {
_PyUOpInstruction *writebuffer;
_PyUOpInstruction *writebuffer_end;
// Calculated from writebuffer_end + n_scratch_slots
int n_scratch_slots;
int curr_i;
} _Py_UOpsEmitter;

static inline int
emit_i(_PyUOpInstruction *trace_writebuffer, _PyUOpInstruction *writebuffer_end,
int curr_i, _PyUOpInstruction inst)
emit_i(_Py_UOpsEmitter *emitter,
_PyUOpInstruction inst)
{
#ifdef Py_DEBUG
char *uop_debug = Py_GETENV("PYTHONUOPSDEBUG");
Expand All @@ -1259,26 +1267,35 @@ emit_i(_PyUOpInstruction *trace_writebuffer, _PyUOpInstruction *writebuffer_end,
lltrace = *uop_debug - '0'; // TODO: Parse an int and all that
}
#endif
if (curr_i < 0) {
if (emitter->curr_i < 0) {
return -1;
}
if (trace_writebuffer + curr_i >= writebuffer_end) {
if (emitter->writebuffer + emitter->curr_i >= emitter->writebuffer_end) {
return -1;
}
DPRINTF(2, "Emitting instruction at [%d] op: %s, oparg: %d, operand: %" PRIu64 " \n",
curr_i,
emitter->curr_i,
(inst.opcode >= 300 ? _PyOpcode_uop_name : _PyOpcode_OpName)[inst.opcode],
inst.oparg,
inst.operand);
trace_writebuffer[curr_i] = inst;
return curr_i + 1;
emitter->writebuffer[emitter->curr_i] = inst;
emitter->curr_i++;
return 0;
}

static inline int
emit_common(_PyUOpInstruction *trace_writebuffer,
_PyUOpInstruction *writebuffer_end,
int curr_i,
_PyUOpInstruction inst)
{

}

static int
compile_sym_to_uops(_PyUOpInstruction *trace_writebuffer,
_PyUOpInstruction *writebuffer_end,
int new_trace_len,
_Py_UOpsSymbolicExpression *sym, _Py_UOpsPureStore *store,
compile_sym_to_uops(_Py_UOpsEmitter *emitter,
_Py_UOpsSymbolicExpression *sym,
_Py_UOpsPureStore *store,
bool use_locals)
{
_PyUOpInstruction inst;
Expand All @@ -1291,14 +1308,15 @@ compile_sym_to_uops(_PyUOpInstruction *trace_writebuffer,
inst.oparg = 0;
// TODO memory leak.
inst.operand = (uint64_t)Py_NewRef(sym->const_val);
return emit_i(trace_writebuffer, writebuffer_end, new_trace_len, inst);
return emit_i(emitter, inst);
}


// Common subexpression elimination.
// If this is used elsewhere, store it in a scratch slot.
if (sym->usage_count > 1 && sym->emitted_count < (sym->usage_count - 1)) {
sym->emitted_count++;
// First check - is it already in a scratch slot somewhere?

}

Expand All @@ -1312,7 +1330,7 @@ compile_sym_to_uops(_PyUOpInstruction *trace_writebuffer,
inst.opcode = LOAD_FAST;
inst.oparg = i;
inst.operand = 0;
return emit_i(trace_writebuffer, writebuffer_end, new_trace_len, inst);
return emit_i(emitter, inst);
}
}
}
Expand All @@ -1321,11 +1339,11 @@ compile_sym_to_uops(_PyUOpInstruction *trace_writebuffer,
// These are for unknown stack entries.
if (_PyOpcode_isunknown(sym->inst.opcode)) {
// Leave it be. These are initial values from the start
return new_trace_len;
return;
}
inst = sym->inst;
inst.opcode = sym->inst.opcode == INIT_FAST ? LOAD_FAST : sym->inst.opcode;
return emit_i(trace_writebuffer, writebuffer_end, new_trace_len, inst);
return emit_i(emitter, inst);
}

// Compile each operand
Expand All @@ -1335,25 +1353,23 @@ compile_sym_to_uops(_PyUOpInstruction *trace_writebuffer,
continue;
}
// TODO Py_EnterRecursiveCall ?
new_trace_len = compile_sym_to_uops(
trace_writebuffer,
writebuffer_end,
new_trace_len,
if (compile_sym_to_uops(
emitter,
sym->operands[i],
store, use_locals);
store, use_locals) < 0) {
return -1;
}
}

// Finally, emit the operation itself.
return emit_i(trace_writebuffer, writebuffer_end, new_trace_len, sym->inst);
return emit_i(emitter, sym->inst);
}

static int
emit_uops_from_pure_store(
PyCodeObject *co,
_Py_UOpsPureStore *pure_store,
_PyUOpInstruction *trace_writebuffer,
_PyUOpInstruction *writebuffer_end,
int new_trace_len
_Py_UOpsEmitter *emitter
)
{
#ifdef Py_DEBUG
Expand Down Expand Up @@ -1381,11 +1397,10 @@ emit_uops_from_pure_store(
// Search local for the thing
for (int locals_idx = 0; locals_idx < locals_len; locals_idx++) {
if (guard_operand == pure_store->initial_locals[locals_idx]) {
_PyUOpInstruction load_fast = {_LOAD_FAST_NO_INCREF, locals_idx, 0};
new_trace_len = emit_i(trace_writebuffer,
writebuffer_end,
new_trace_len,
load_fast);
_PyUOpInstruction load_fast = {_LOAD_FAST_NO_INCREF, locals_idx, 0, 0};
if (emit_i(emitter,load_fast) < 0) {
return -1;
}
load_fast_count++;
break;
}
Expand All @@ -1395,8 +1410,9 @@ emit_uops_from_pure_store(
assert(load_fast_count == guard_operands_count);
stack_grown += load_fast_count;
// Now, time to emit the guard itself
new_trace_len = emit_i(trace_writebuffer, writebuffer_end, new_trace_len,
guard->inst);
if (emit_i(emitter, guard->inst) < 0) {
return -1;
}

}

Expand All @@ -1405,8 +1421,9 @@ emit_uops_from_pure_store(
// TODO HIGH PRIORITY on any deoptimize, the stack needs to be popped by the deopt too.
_PyUOpInstruction stack_shrink = {_SHRINK_STACK, stack_grown, 0};

new_trace_len = emit_i(trace_writebuffer, writebuffer_end, new_trace_len,
stack_shrink);
if (emit_i(emitter, stack_shrink) < 0) {
return -1;
}
}

// 2. Emit the pure region itself.
Expand All @@ -1423,22 +1440,24 @@ emit_uops_from_pure_store(
if (pure_store->locals[locals_i] == pure_store->initial_locals[locals_i]) {
continue;
}
new_trace_len = compile_sym_to_uops(
trace_writebuffer,
writebuffer_end,
new_trace_len,
if (compile_sym_to_uops(
emitter,
pure_store->locals[locals_i],
pure_store,
false);
_PyUOpInstruction prev_i = trace_writebuffer[new_trace_len-1];
false) < 0) {
return -1;
}
_PyUOpInstruction prev_i = emitter->writebuffer[emitter->curr_i-1];
// Micro optimizations -- if LOAD_FAST then STORE_FAST, get rid of that
if (prev_i.opcode == LOAD_FAST && prev_i.oparg == locals_i) {
new_trace_len--;
emitter->curr_i--;
DPRINTF(3, "LOAD_FAST to be followed by STORE_FAST, ignoring LOAD_FAST. \n");
continue;
}
_PyUOpInstruction store_fast = {STORE_FAST, locals_i, 0, 0};
new_trace_len = emit_i(trace_writebuffer, writebuffer_end, new_trace_len, store_fast);
if (emit_i(emitter, store_fast) < 0) {
return -1;
}
}
DPRINTF(2, "==================\n");
DPRINTF(2, "==EMITTING STACK==:\n");
Expand All @@ -1450,26 +1469,24 @@ emit_uops_from_pure_store(
continue;
}

new_trace_len = compile_sym_to_uops(
trace_writebuffer,
writebuffer_end,
new_trace_len,
if (compile_sym_to_uops(
emitter,
pure_store->stack[stack_i],
pure_store,
true);
true) < 0) {
return -1;
}
}
DPRINTF(2, "==================\n");

return new_trace_len;
return 0;
}

static int
emit_uops_from_impure_store(
PyCodeObject *co,
_Py_UOpsImpureStore *impure_store,
_PyUOpInstruction *trace_writebuffer,
_PyUOpInstruction *writebuffer_end,
int new_trace_len
_Py_UOpsEmitter *emitter
)
{
#ifdef Py_DEBUG
Expand All @@ -1483,27 +1500,30 @@ emit_uops_from_impure_store(
Py_ssize_t len = (impure_store->end - impure_store->start);
assert(impure_store->start->opcode == _SET_IP);

if (emitter->writebuffer + len >= emitter->writebuffer_end) {
return -1;
}

#ifdef Py_DEBUG
for (Py_ssize_t i = 0; i < len; i++) {
_PyUOpInstruction inst = impure_store->start[i];
DPRINTF(2, "Emitting instruction at [%d] op: %s, oparg: %d, operand: %" PRIu64 " \n",
(int)(new_trace_len + i),
(int)(emitter->curr_i + i),
(inst.opcode >= 300 ? _PyOpcode_uop_name : _PyOpcode_OpName)[inst.opcode],
inst.oparg,
inst.operand);
}
#endif

if (trace_writebuffer + len >= writebuffer_end) {
return -1;
}

memcpy(
trace_writebuffer + new_trace_len,
emitter->writebuffer + emitter->curr_i,
impure_store->start,
len* sizeof(_PyUOpInstruction)
len * sizeof(_PyUOpInstruction)
);
return new_trace_len + (int)len;

emitter->curr_i += len;
return 0;
}

static int
Expand All @@ -1515,7 +1535,12 @@ emit_uops_from_stores(
)
{

int new_trace_len = 0;
_Py_UOpsEmitter emitter = {
trace_writebuffer,
writebuffer_end,
0,
0,
};

// Emission is simple: traverse the linked list of stores:
// - For pure stores, emit their final states.
Expand All @@ -1526,24 +1551,28 @@ emit_uops_from_stores(
_Py_UOpsStoreUnion *curr_store = first_store;
while(curr_store != NULL) {
if (curr_store->pure_or_impure) {
new_trace_len = emit_uops_from_pure_store(co,
if (emit_uops_from_pure_store(co,
(_Py_UOpsPureStore *)curr_store,
trace_writebuffer,
writebuffer_end,
new_trace_len);
&emitter) < 0) {
return -1;
}
}
else {
new_trace_len = emit_uops_from_impure_store(co,
if (emit_uops_from_impure_store(co,
(_Py_UOpsImpureStore *)curr_store,
trace_writebuffer,
writebuffer_end,
new_trace_len);
&emitter) < 0) {
return -1;
}
}
curr_store = curr_store->next;
}


return new_trace_len;
// Add the _JUMP_TO_TOP at the end of the trace.
_PyUOpInstruction jump_to_top = {_JUMP_TO_TOP, 0, 0};
if (emit_i(&emitter, jump_to_top) < 0) {
return -1;
}
return emitter.curr_i;
}
static void
remove_unneeded_uops(_PyUOpInstruction *buffer, int buffer_size)
Expand Down Expand Up @@ -1624,15 +1653,8 @@ _Py_uop_analyze_and_optimize(
goto error;
}

// Add the _JUMP_TO_TOP
_PyUOpInstruction jump_to_top = {_JUMP_TO_TOP, 0, 0};
trace_len = emit_i(temp_writebuffer, writebuffer_end, trace_len, jump_to_top);
if (trace_len < 0) {
goto error;
}

// Pass: fix up side exit stubs. This MUST be called as the last pass!
trace_len = copy_over_exit_stubs(buffer, original_trace_len, temp_writebuffer, trace_len);
// trace_len = copy_over_exit_stubs(buffer, original_trace_len, temp_writebuffer, trace_len);

// Fill in our new trace!
memcpy(buffer, temp_writebuffer, trace_len * sizeof(_PyUOpInstruction));
Expand Down

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