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Fix GH-15656: php8.4beta4 JIT erronous results #15732

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Merged
merged 7 commits into from
Sep 9, 2024
Merged

Fix GH-15656: php8.4beta4 JIT erronous results #15732

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8d2d12c
Improve trace SSA construction and type inference
dstogov Sep 3, 2024
14d168e
Fix incorrect abstract stack maintenance
dstogov Sep 3, 2024
b4ff18b
Add missing register store
dstogov Sep 3, 2024
6b3f48d
Avoid IR binding for the dangerous case
dstogov Sep 3, 2024
ad557b8
Fix access to possibly uninitilezed variable
dstogov Sep 3, 2024
2eae9c4
Improve trace SSA construction and type inference
dstogov Sep 3, 2024
e67ad92
Fix IR constuction
dstogov Sep 4, 2024
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27 changes: 27 additions & 0 deletions ext/opcache/jit/zend_jit_ir.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1289,6 +1289,16 @@ static bool zend_jit_spilling_may_cause_conflict(zend_jit_ctx *jit, int var, ir_
// }
if (jit->ssa->vars[var].var < jit->current_op_array->last_var) {
/* IS_CV */
if (jit->ctx.ir_base[val].op == IR_LOAD
&& jit->ctx.ir_base[jit->ctx.ir_base[val].op2].op == IR_ADD
&& jit->ctx.ir_base[jit->ctx.ir_base[jit->ctx.ir_base[val].op2].op1].op == IR_RLOAD
&& jit->ctx.ir_base[jit->ctx.ir_base[jit->ctx.ir_base[val].op2].op1].op2 == ZREG_FP
&& IR_IS_CONST_REF(jit->ctx.ir_base[jit->ctx.ir_base[val].op2].op2)
&& jit->ctx.ir_base[jit->ctx.ir_base[jit->ctx.ir_base[val].op2].op2].val.addr != (uintptr_t)EX_NUM_TO_VAR(jit->ssa->vars[var].var)
&& EX_VAR_TO_NUM(jit->ctx.ir_base[jit->ctx.ir_base[jit->ctx.ir_base[val].op2].op2].val.addr) < jit->current_op_array->last_var) {
/* binding between different CVs may cause spill conflict */
return 1;
}
return 0;
}
return 1;
Expand Down Expand Up @@ -5561,6 +5571,19 @@ static int zend_jit_long_math_helper(zend_jit_ctx *jit,

ir_refs_init(res_inputs, 2);

if (Z_MODE(op1_addr) == IS_REG
&& Z_LOAD(op1_addr)
&& jit->ra[Z_SSA_VAR(op1_addr)].ref == IR_NULL) {
/* Force load */
zend_jit_use_reg(jit, op1_addr);
}
if (Z_MODE(op2_addr) == IS_REG
&& Z_LOAD(op2_addr)
&& jit->ra[Z_SSA_VAR(op2_addr)].ref == IR_NULL) {
/* Force load */
zend_jit_use_reg(jit, op2_addr);
}

if (op1_info & ((MAY_BE_ANY|MAY_BE_UNDEF)-MAY_BE_LONG)) {
if_long1 = jit_if_Z_TYPE(jit, op1_addr, IS_LONG);
ir_IF_TRUE(if_long1);
Expand Down Expand Up @@ -6088,6 +6111,10 @@ static int zend_jit_assign_op(zend_jit_ctx *jit,
ZEND_UNREACHABLE();
}

if (!zend_jit_store_var_if_necessary_ex(jit, opline->op1.var, op1_def_addr, op1_def_info, op1_addr, op1_info)) {
return 0;
}

if (op1_info & MAY_BE_REF) {
ir_MERGE_WITH(slow_path);
}
Expand Down
75 changes: 66 additions & 9 deletions ext/opcache/jit/zend_jit_trace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -805,7 +805,12 @@ static bool zend_jit_trace_is_false_loop(const zend_op_array *op_array, const ze
}
}

static int zend_jit_trace_copy_ssa_var_info(const zend_op_array *op_array, const zend_ssa *ssa, const zend_op **tssa_opcodes, zend_ssa *tssa, int ssa_var)
static int zend_jit_trace_copy_ssa_var_info(const zend_op_array *op_array,
const zend_ssa *ssa,
const zend_op **tssa_opcodes,
zend_ssa *tssa,
int ssa_var,
const zend_op *opline)
{
int var, use, def, src;
zend_ssa_op *op;
Expand Down Expand Up @@ -913,6 +918,54 @@ static int zend_jit_trace_copy_ssa_var_info(const zend_op_array *op_array, const
assert(0);
return 0;
}
if (opline) {
/* Try to find a difinition in SSA dominators tree */
var = tssa->vars[ssa_var].var;
uint32_t op_num = opline - op_array->opcodes;
uint32_t b = ssa->cfg.map[op_num];
zend_basic_block *bb = ssa->cfg.blocks + b;
zend_ssa_phi *pi, *phi;

while (1) {
while (op_num > bb->start) {
op_num--;
op = ssa->ops + op_num;
if (op->result_def >= 0 && ssa->vars[op->result_def].var == var) {
src = op->result_def;
goto copy_info;
} else if (op->op2_def >= 0 && ssa->vars[op->op2_def].var == var) {
src = op->op2_def;
goto copy_info;
} else if (op->op1_def >= 0 && ssa->vars[op->op1_def].var == var) {
src = op->op1_def;
goto copy_info;
}
}
phi = ssa->blocks[b].phis;
pi = NULL;
while (phi) {
if (ssa->vars[phi->ssa_var].var == var) {
if (phi->pi >= 0) {
pi = phi;
} else {
src = phi->ssa_var;
goto copy_info;
}
}
phi = phi->next;
}
if (pi) {
src = pi->ssa_var;
goto copy_info;
}
if (bb->idom < 0) {
break;
}
b = bb->idom;
bb = ssa->cfg.blocks + b;
op_num = bb->start + bb->len;
}
}
goto copy_info;
}
return 0;
Expand Down Expand Up @@ -1586,6 +1639,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin

/* 4. Type inference */
op_array = trace_buffer->op_array;
opline = trace_buffer[1].opline;
jit_extension =
(zend_jit_op_array_trace_extension*)ZEND_FUNC_INFO(op_array);
ssa = &jit_extension->func_info.ssa;
Expand All @@ -1597,7 +1651,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin
while (i < op_array->last_var) {
if (i < op_array->num_args) {
if (ssa->var_info
&& zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, i)) {
&& zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, i, NULL)) {
/* pass */
} else {
if (ssa->vars) {
Expand Down Expand Up @@ -1652,7 +1706,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin
}
while (i < op_array->last_var + op_array->T) {
if (!ssa->var_info
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, i)) {
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, i, opline)) {
if (ssa->vars && i < ssa->vars_count) {
ssa_vars[i].alias = ssa->vars[i].alias;
} else {
Expand Down Expand Up @@ -1690,7 +1744,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin

while (phi) {
if (!ssa->var_info
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, phi->ssa_var)) {
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, phi->ssa_var, NULL)) {
ssa_vars[phi->ssa_var].alias = ssa_vars[phi->sources[0]].alias;
ssa_var_info[phi->ssa_var].type = ssa_var_info[phi->sources[0]].type;
}
Expand Down Expand Up @@ -2409,7 +2463,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin
ssa_vars[v].var = i;
if (i < op_array->num_args) {
if (ssa->var_info
&& zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, v)) {
&& zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, v, NULL)) {
/* pass */
} else {
ssa_vars[v].alias = zend_jit_var_may_alias(op_array, ssa, i);
Expand Down Expand Up @@ -2460,7 +2514,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin
while (i < op_array->last_var) {
ssa_vars[v].var = i;
if (!ssa->var_info
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, v)) {
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, v, NULL)) {
ssa_var_info[v].type = MAY_BE_UNDEF | MAY_BE_RC1 | MAY_BE_RCN | MAY_BE_REF | MAY_BE_ANY | MAY_BE_ARRAY_KEY_ANY | MAY_BE_ARRAY_OF_ANY | MAY_BE_ARRAY_OF_REF;
}
i++;
Expand All @@ -2469,7 +2523,7 @@ static zend_ssa *zend_jit_trace_build_tssa(zend_jit_trace_rec *trace_buffer, uin
while (i < op_array->last_var + op_array->T) {
ssa_vars[v].var = i;
if (!ssa->var_info
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, v)) {
|| !zend_jit_trace_copy_ssa_var_info(op_array, ssa, ssa_opcodes, tssa, v, NULL)) {
ssa_var_info[v].type = MAY_BE_RC1 | MAY_BE_RCN | MAY_BE_REF | MAY_BE_ANY | MAY_BE_ARRAY_KEY_ANY | MAY_BE_ARRAY_OF_ANY | MAY_BE_ARRAY_OF_REF;
}
i++;
Expand Down Expand Up @@ -3308,13 +3362,16 @@ static void zend_jit_trace_cleanup_stack(zend_jit_ctx *jit, zend_jit_trace_stack
CLEAR_STACK_REF(stack, EX_VAR_TO_NUM(opline->op1.var));
}
if (ssa_op->op2_use >= 0
&& ssa_op->op2_use != ssa_op->op1_use
&& jit->ra[ssa_op->op2_use].ref
&& (jit->ra[ssa_op->op2_use].flags & ZREG_LAST_USE)
&& (ssa_op->op2_use_chain == -1
|| zend_ssa_is_no_val_use(ssa_opcodes[ssa_op->op2_use_chain], ssa->ops + ssa_op->op2_use_chain, ssa_op->op2_use))) {
CLEAR_STACK_REF(stack, EX_VAR_TO_NUM(opline->op2.var));
}
if (ssa_op->result_use >= 0
&& ssa_op->result_use != ssa_op->op1_use
&& ssa_op->result_use != ssa_op->op2_use
&& jit->ra[ssa_op->result_use].ref
&& (jit->ra[ssa_op->result_use].flags & ZREG_LAST_USE)
&& (ssa_op->res_use_chain == -1
Expand Down Expand Up @@ -4143,8 +4200,8 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
} else if (i < parent_vars_count
&& STACK_TYPE(parent_stack, i) != IS_UNKNOWN) {
/* This must be already handled by trace type inference */
ZEND_UNREACHABLE();
// SET_STACK_TYPE(stack, i, STACK_TYPE(parent_stack, i));
ZEND_ASSERT(ssa->vars[i].use_chain < 0 && !ssa->vars[i].phi_use_chain);
SET_STACK_TYPE(stack, i, STACK_TYPE(parent_stack, i), 1);
} else if ((info & MAY_BE_GUARD) != 0
&& (trace_buffer->stop == ZEND_JIT_TRACE_STOP_LOOP
|| trace_buffer->stop == ZEND_JIT_TRACE_STOP_RECURSIVE_CALL
Expand Down