com php-src: Remove dead construction of non-escaping arrays and objects: ext/opcache/Optimizer/sccp.c ext/opcache/tests/opt/sccp_0 12.phpt
| From: | Dmitry Stogov | Date: | Thu, 31 Aug 2017 14:17:04 +0000 |
| Subject: | com php-src: Remove dead construction of non-escaping arrays and objects: ext/opcache/Optimizer/sccp.c ext/opcache/tests/opt/sccp_0 12.phpt | ||
| Groups: | php.cvs | ||
| Request: | Send a blank email to php-cvs+get-99209@lists.php.net to get a copy of this message | ||
Commit: 6cc9e805cdbef0729f9b9316f9be6109a69db5e0
Author: Dmitry Stogov <dmitry@zend.com> Thu, 31 Aug 2017 17:17:04 +0300
Parents: 1eb6fd8bc47b8aab2239f1b1f317f3362639070f
Branches: master
Link: http://git.php.net/?p=php-src.git;a=commitdiff;h=6cc9e805cdbef0729f9b9316f9be6109a69db5e0
Log:
Remove dead construction of non-escaping arrays and objects
Changed paths:
M ext/opcache/Optimizer/sccp.c
A ext/opcache/tests/opt/sccp_012.phpt
diff --git a/ext/opcache/Optimizer/sccp.c b/ext/opcache/Optimizer/sccp.c index 4d9eb57..8a08a48 100644 --- a/ext/opcache/Optimizer/sccp.c +++ b/ext/opcache/Optimizer/sccp.c @@ -21,6 +21,7 @@ #include "ZendAccelerator.h" #include "Optimizer/zend_optimizer_internal.h" #include "Optimizer/zend_call_graph.h" +#include "Optimizer/zend_inference.h" #include "Optimizer/scdf.h" #include "Optimizer/zend_dump.h" #include "ext/standard/php_string.h" @@ -1916,6 +1917,184 @@ static zval *value_from_type_and_range(sccp_ctx *ctx, int var_num, zval *tmp) { return NULL; } +/* This is a basic DCE pass we run after SCCP. It only works on those instructions those result + * value(s) were determined by SCCP. It removes dead computational instructions and converts + * CV-affecting instructions into CONST ASSIGNs. This basic DCE is performed for multiple reasons: + * a) During operand replacement we eliminate FREEs. The corresponding computational instructions + * must be removed to avoid leaks. This way SCCP can run independently of the full DCE pass. + * b) The main DCE pass relies on type analysis to determine whether instructions have side-effects + * and can't be DCEd. This means that it will not be able collect all instructions rendered dead + * by SCCP, because they may have potentially side-effecting types, but the actual values are + * not. As such doing DCE here will allow us to eliminate more dead code in combination. + * c) The ordinary DCE pass cannot collect dead calls. However SCCP can result in dead calls, which + * we need to collect. + * d) The ordinary DCE pass cannot collect construction of dead non-escaping arrays and objects. + */ +static int try_remove_definition(sccp_ctx *ctx, int var_num, zend_ssa_var *var, zval *value) +{ + zend_ssa *ssa = ctx->scdf.ssa; + zend_op_array *op_array = ctx->scdf.op_array; + int removed_ops = 0; + + if (var->definition >= 0) { + zend_op *opline = &op_array->opcodes[var->definition]; + zend_ssa_op *ssa_op = &ssa->ops[var->definition]; + + if (opline->opcode == ZEND_ASSIGN) { + /* Leave assigns to DCE (due to dtor effects) */ + return 0; + } + + if (ssa_op->result_def == var_num + && ssa_op->op1_def < 0 + && ssa_op->op2_def < 0 + && var->use_chain < 0 + && var->phi_use_chain == NULL) { + if (opline->opcode == ZEND_DO_ICALL) { + /* Call instruction -> remove opcodes that are part of the call */ + zend_call_info *call; + int i; + + ZEND_ASSERT(ctx->call_map); + call = ctx->call_map[var->definition]; + ZEND_ASSERT(call); + ZEND_ASSERT(call->caller_call_opline == opline); + if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { + zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); + } + zend_ssa_remove_result_def(ssa, ssa_op); + zend_ssa_remove_instr(ssa, opline, ssa_op); + zend_ssa_remove_instr(ssa, call->caller_init_opline, + &ssa->ops[call->caller_init_opline - op_array->opcodes]); + + for (i = 0; i < call->num_args; i++) { + zend_ssa_remove_instr(ssa, call->arg_info[i].opline, + &ssa->ops[call->arg_info[i].opline - op_array->opcodes]); + } + removed_ops = call->num_args + 2; + + // TODO: remove call_info completely??? + call->callee_func = NULL; + } else { + /* Ordinary computational instruction -> remove it */ + if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { + zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); + } + zend_ssa_remove_result_def(ssa, ssa_op); + zend_ssa_remove_instr(ssa, opline, ssa_op); + removed_ops++; + } + } else if (ssa_op->op1_def == var_num) { + /* Compound assign or incdec -> convert to direct ASSIGN */ + + switch (opline->opcode) { + case ZEND_ASSIGN_DIM: + case ZEND_ASSIGN_OBJ: + case ZEND_ASSIGN_ADD: + case ZEND_ASSIGN_SUB: + case ZEND_ASSIGN_MUL: + case ZEND_ASSIGN_DIV: + case ZEND_ASSIGN_MOD: + case ZEND_ASSIGN_SL: + case ZEND_ASSIGN_SR: + case ZEND_ASSIGN_CONCAT: + case ZEND_ASSIGN_BW_OR: + case ZEND_ASSIGN_BW_AND: + case ZEND_ASSIGN_BW_XOR: + case ZEND_ASSIGN_POW: + case ZEND_PRE_INC_OBJ: + case ZEND_PRE_DEC_OBJ: + case ZEND_POST_INC_OBJ: + case ZEND_POST_DEC_OBJ: + if (opline->op2_type == IS_CV) { + if (OP2_INFO() & MAY_BE_UNDEF) { + return 0; + } + } + default: + break; + } + + /* Mark result unused, if possible */ + if (ssa_op->result_def >= 0) { + if (ssa->vars[ssa_op->result_def].use_chain < 0 + && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) { + if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { + zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); + } + zend_ssa_remove_result_def(ssa, ssa_op); + opline->result_type = IS_UNUSED; + } else if (opline->opcode != ZEND_PRE_INC && + opline->opcode != ZEND_PRE_DEC) { + /* op1_def and result_def are different */ + return removed_ops; + } + } + + /* Destroy previous op2 */ + if (opline->op2_type == IS_CONST) { + literal_dtor(&ZEND_OP2_LITERAL(opline)); + } else if (ssa_op->op2_use >= 0) { + if (ssa_op->op2_use != ssa_op->op1_use) { + zend_ssa_unlink_use_chain(ssa, var->definition, ssa_op->op2_use); + } + ssa_op->op2_use = -1; + ssa_op->op2_use_chain = -1; + } + + /* Remove OP_DATA opcode */ + switch (opline->opcode) { + case ZEND_ASSIGN_DIM: + case ZEND_ASSIGN_OBJ: + removed_ops++; + zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1); + break; + case ZEND_ASSIGN_ADD: + case ZEND_ASSIGN_SUB: + case ZEND_ASSIGN_MUL: + case ZEND_ASSIGN_DIV: + case ZEND_ASSIGN_MOD: + case ZEND_ASSIGN_SL: + case ZEND_ASSIGN_SR: + case ZEND_ASSIGN_CONCAT: + case ZEND_ASSIGN_BW_OR: + case ZEND_ASSIGN_BW_AND: + case ZEND_ASSIGN_BW_XOR: + case ZEND_ASSIGN_POW: + if (opline->extended_value) { + removed_ops++; + zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1); + } + break; + default: + break; + } + + if (value) { + /* Convert to ASSIGN */ + opline->opcode = ZEND_ASSIGN; + opline->op2_type = IS_CONST; + opline->op2.constant = zend_optimizer_add_literal(op_array, value); + Z_TRY_ADDREF_P(value); + } else { + /* Remove dead array or object construction */ + removed_ops++; + if (var->use_chain >= 0 || var->phi_use_chain != NULL) { + zend_ssa_rename_var_uses(ssa, ssa_op->op1_def, ssa_op->op1_use, 1); + } + zend_ssa_remove_op1_def(ssa, ssa_op); + zend_ssa_remove_instr(ssa, opline, ssa_op); + } + } + } + if (var->definition_phi + && var->use_chain < 0 + && var->phi_use_chain == NULL) { + zend_ssa_remove_phi(ssa, var->definition_phi); + } + return removed_ops; +} + /* This will try to replace uses of SSA variables we have determined to be constant. Not all uses * can be replaced, because some instructions don't accept constant operands or only accept them * if they have a certain type. */ @@ -1939,6 +2118,9 @@ static int replace_constant_operands(sccp_ctx *ctx) { zend_array_destroy(Z_ARR(ctx->values[i])); } Z_TYPE_INFO(ctx->values[i]) = BOT; + if ((var->use_chain < 0 && var->phi_use_chain == NULL) || var->no_val) { + removed_ops += try_remove_definition(ctx, i, var, NULL); + } continue; } else if (value_known(&ctx->values[i])) { value = &ctx->values[i]; @@ -1973,108 +2155,8 @@ static int replace_constant_operands(sccp_ctx *ctx) { } } FOREACH_USE_END(); - /* This is a basic DCE pass we run after SCCP. It only works on those instructions those result - * value(s) were determined by SCCP. It removes dead computational instructions and converts - * CV-affecting instructions into CONST ASSIGNs. This basic DCE is performed for multiple reasons: - * a) During operand replacement we eliminate FREEs. The corresponding computational instructions - * must be removed to avoid leaks. This way SCCP can run independently of the full DCE pass. - * b) The main DCE pass relies on type analysis to determine whether instructions have side-effects - * and can't be DCEd. This means that it will not be able collect all instructions rendered dead - * by SCCP, because they may have potentially side-effecting types, but the actual values are - * not. As such doing DCE here will allow us to eliminate more dead code in combination. - * c) The ordinary DCE pass cannot collect dead calls. However SCCP can result in dead calls, which - * we need to collect. */ - - if (var->definition >= 0 && value_known(&ctx->values[i])) { - zend_op *opline = &op_array->opcodes[var->definition]; - zend_ssa_op *ssa_op = &ssa->ops[var->definition]; - if (opline->opcode == ZEND_ASSIGN) { - /* Leave assigns to DCE (due to dtor effects) */ - continue; - } - - if (ssa_op->result_def == i - && ssa_op->op1_def < 0 - && ssa_op->op2_def < 0 - && var->use_chain < 0 - && var->phi_use_chain == NULL) { - if (opline->opcode == ZEND_DO_ICALL) { - /* Call instruction -> remove opcodes that are part of the call */ - zend_call_info *call; - int i; - - ZEND_ASSERT(ctx->call_map); - call = ctx->call_map[var->definition]; - ZEND_ASSERT(call); - ZEND_ASSERT(call->caller_call_opline == opline); - if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { - zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); - } - zend_ssa_remove_result_def(ssa, ssa_op); - zend_ssa_remove_instr(ssa, opline, ssa_op); - zend_ssa_remove_instr(ssa, call->caller_init_opline, - &ssa->ops[call->caller_init_opline - op_array->opcodes]); - - for (i = 0; i < call->num_args; i++) { - zend_ssa_remove_instr(ssa, call->arg_info[i].opline, - &ssa->ops[call->arg_info[i].opline - op_array->opcodes]); - } - removed_ops = call->num_args + 2; - - // TODO: remove call_info completely??? - call->callee_func = NULL; - } else { - /* Ordinary computational instruction -> remove it */ - if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { - zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); - } - zend_ssa_remove_result_def(ssa, ssa_op); - zend_ssa_remove_instr(ssa, opline, ssa_op); - removed_ops++; - } - } else if (ssa_op->op1_def == i) { - /* Compound assign or incdec -> convert to direct ASSIGN */ - - /* Destroy previous op2 */ - if (opline->op2_type == IS_CONST) { - literal_dtor(&ZEND_OP2_LITERAL(opline)); - } else if (ssa_op->op2_use >= 0) { - if (ssa_op->op2_use != ssa_op->op1_use) { - zend_ssa_unlink_use_chain(ssa, var->definition, ssa_op->op2_use); - } - ssa_op->op2_use = -1; - ssa_op->op2_use_chain = -1; - } - - /* Mark result unused, if possible */ - if (ssa_op->result_def >= 0 - && ssa->vars[ssa_op->result_def].use_chain < 0 - && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) { - if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { - zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); - } - zend_ssa_remove_result_def(ssa, ssa_op); - opline->result_type = IS_UNUSED; - } - - /* Remove OP_DATA opcode */ - if (opline->opcode == ZEND_ASSIGN_DIM) { - removed_ops++; - zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1); - } - - /* Convert to ASSIGN */ - opline->opcode = ZEND_ASSIGN; - opline->op2_type = IS_CONST; - opline->op2.constant = zend_optimizer_add_literal(op_array, value); - Z_TRY_ADDREF_P(value); - } - } - if (var->definition_phi - && value_known(&ctx->values[i]) - && var->use_chain < 0 - && var->phi_use_chain == NULL) { - zend_ssa_remove_phi(ssa, var->definition_phi); + if (value_known(&ctx->values[i])) { + removed_ops += try_remove_definition(ctx, i, var, value); } } diff --git a/ext/opcache/tests/opt/sccp_012.phpt b/ext/opcache/tests/opt/sccp_012.phpt new file mode 100644 index 0000000..ae56057 --- /dev/null +++ b/ext/opcache/tests/opt/sccp_012.phpt @@ -0,0 +1,41 @@ +--TEST-- +SCCP 012: Conditional Constant Propagation of non-escaping object properties +--INI-- +opcache.enable=1 +opcache.enable_cli=1 +opcache.optimization_level=-1 +opcache.opt_debug_level=0x20000 +--SKIPIF-- +<?php require_once('skipif.inc'); ?> +--FILE-- +<?php +function foo() { + $o = new stdClass(); + $o->foo = 0; + $i = 1; + $c = $i < 2; + if ($c) { + $k = 2 * $i; + $o->foo = $i; + echo $o->foo; + } + $o->foo += 2; + $o->foo++; + echo $o->foo; +} +?> +--EXPECTF-- +$_main: ; (lines=1, args=0, vars=0, tmps=0) + ; (after optimizer) + ; %ssccp_012.php:1-17 +L0: RETURN int(1) + +foo: ; (lines=6, args=0, vars=0, tmps=1) + ; (after optimizer) + ; %ssccp_012.php:2-15 +L0: V0 = NEW 0 string("stdClass") +L1: DO_FCALL +L2: FREE V0 +L3: ECHO int(1) +L4: ECHO int(4) +L5: RETURN null
diff --git a/ext/opcache/Optimizer/sccp.c b/ext/opcache/Optimizer/sccp.c index 4d9eb57..8a08a48 100644 --- a/ext/opcache/Optimizer/sccp.c +++ b/ext/opcache/Optimizer/sccp.c @@ -21,6 +21,7 @@ #include "ZendAccelerator.h" #include "Optimizer/zend_optimizer_internal.h" #include "Optimizer/zend_call_graph.h" +#include "Optimizer/zend_inference.h" #include "Optimizer/scdf.h" #include "Optimizer/zend_dump.h" #include "ext/standard/php_string.h" @@ -1916,6 +1917,184 @@ static zval *value_from_type_and_range(sccp_ctx *ctx, int var_num, zval *tmp) { return NULL; } +/* This is a basic DCE pass we run after SCCP. It only works on those instructions those result + * value(s) were determined by SCCP. It removes dead computational instructions and converts + * CV-affecting instructions into CONST ASSIGNs. This basic DCE is performed for multiple reasons: + * a) During operand replacement we eliminate FREEs. The corresponding computational instructions + * must be removed to avoid leaks. This way SCCP can run independently of the full DCE pass. + * b) The main DCE pass relies on type analysis to determine whether instructions have side-effects + * and can't be DCEd. This means that it will not be able collect all instructions rendered dead + * by SCCP, because they may have potentially side-effecting types, but the actual values are + * not. As such doing DCE here will allow us to eliminate more dead code in combination. + * c) The ordinary DCE pass cannot collect dead calls. However SCCP can result in dead calls, which + * we need to collect. + * d) The ordinary DCE pass cannot collect construction of dead non-escaping arrays and objects. + */ +static int try_remove_definition(sccp_ctx *ctx, int var_num, zend_ssa_var *var, zval *value) +{ + zend_ssa *ssa = ctx->scdf.ssa; + zend_op_array *op_array = ctx->scdf.op_array; + int removed_ops = 0; + + if (var->definition >= 0) { + zend_op *opline = &op_array->opcodes[var->definition]; + zend_ssa_op *ssa_op = &ssa->ops[var->definition]; + + if (opline->opcode == ZEND_ASSIGN) { + /* Leave assigns to DCE (due to dtor effects) */ + return 0; + } + + if (ssa_op->result_def == var_num + && ssa_op->op1_def < 0 + && ssa_op->op2_def < 0 + && var->use_chain < 0 + && var->phi_use_chain == NULL) { + if (opline->opcode == ZEND_DO_ICALL) { + /* Call instruction -> remove opcodes that are part of the call */ + zend_call_info *call; + int i; + + ZEND_ASSERT(ctx->call_map); + call = ctx->call_map[var->definition]; + ZEND_ASSERT(call); + ZEND_ASSERT(call->caller_call_opline == opline); + if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { + zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); + } + zend_ssa_remove_result_def(ssa, ssa_op); + zend_ssa_remove_instr(ssa, opline, ssa_op); + zend_ssa_remove_instr(ssa, call->caller_init_opline, + &ssa->ops[call->caller_init_opline - op_array->opcodes]); + + for (i = 0; i < call->num_args; i++) { + zend_ssa_remove_instr(ssa, call->arg_info[i].opline, + &ssa->ops[call->arg_info[i].opline - op_array->opcodes]); + } + removed_ops = call->num_args + 2; + + // TODO: remove call_info completely??? + call->callee_func = NULL; + } else { + /* Ordinary computational instruction -> remove it */ + if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { + zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); + } + zend_ssa_remove_result_def(ssa, ssa_op); + zend_ssa_remove_instr(ssa, opline, ssa_op); + removed_ops++; + } + } else if (ssa_op->op1_def == var_num) { + /* Compound assign or incdec -> convert to direct ASSIGN */ + + switch (opline->opcode) { + case ZEND_ASSIGN_DIM: + case ZEND_ASSIGN_OBJ: + case ZEND_ASSIGN_ADD: + case ZEND_ASSIGN_SUB: + case ZEND_ASSIGN_MUL: + case ZEND_ASSIGN_DIV: + case ZEND_ASSIGN_MOD: + case ZEND_ASSIGN_SL: + case ZEND_ASSIGN_SR: + case ZEND_ASSIGN_CONCAT: + case ZEND_ASSIGN_BW_OR: + case ZEND_ASSIGN_BW_AND: + case ZEND_ASSIGN_BW_XOR: + case ZEND_ASSIGN_POW: + case ZEND_PRE_INC_OBJ: + case ZEND_PRE_DEC_OBJ: + case ZEND_POST_INC_OBJ: + case ZEND_POST_DEC_OBJ: + if (opline->op2_type == IS_CV) { + if (OP2_INFO() & MAY_BE_UNDEF) { + return 0; + } + } + default: + break; + } + + /* Mark result unused, if possible */ + if (ssa_op->result_def >= 0) { + if (ssa->vars[ssa_op->result_def].use_chain < 0 + && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) { + if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { + zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); + } + zend_ssa_remove_result_def(ssa, ssa_op); + opline->result_type = IS_UNUSED; + } else if (opline->opcode != ZEND_PRE_INC && + opline->opcode != ZEND_PRE_DEC) { + /* op1_def and result_def are different */ + return removed_ops; + } + } + + /* Destroy previous op2 */ + if (opline->op2_type == IS_CONST) { + literal_dtor(&ZEND_OP2_LITERAL(opline)); + } else if (ssa_op->op2_use >= 0) { + if (ssa_op->op2_use != ssa_op->op1_use) { + zend_ssa_unlink_use_chain(ssa, var->definition, ssa_op->op2_use); + } + ssa_op->op2_use = -1; + ssa_op->op2_use_chain = -1; + } + + /* Remove OP_DATA opcode */ + switch (opline->opcode) { + case ZEND_ASSIGN_DIM: + case ZEND_ASSIGN_OBJ: + removed_ops++; + zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1); + break; + case ZEND_ASSIGN_ADD: + case ZEND_ASSIGN_SUB: + case ZEND_ASSIGN_MUL: + case ZEND_ASSIGN_DIV: + case ZEND_ASSIGN_MOD: + case ZEND_ASSIGN_SL: + case ZEND_ASSIGN_SR: + case ZEND_ASSIGN_CONCAT: + case ZEND_ASSIGN_BW_OR: + case ZEND_ASSIGN_BW_AND: + case ZEND_ASSIGN_BW_XOR: + case ZEND_ASSIGN_POW: + if (opline->extended_value) { + removed_ops++; + zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1); + } + break; + default: + break; + } + + if (value) { + /* Convert to ASSIGN */ + opline->opcode = ZEND_ASSIGN; + opline->op2_type = IS_CONST; + opline->op2.constant = zend_optimizer_add_literal(op_array, value); + Z_TRY_ADDREF_P(value); + } else { + /* Remove dead array or object construction */ + removed_ops++; + if (var->use_chain >= 0 || var->phi_use_chain != NULL) { + zend_ssa_rename_var_uses(ssa, ssa_op->op1_def, ssa_op->op1_use, 1); + } + zend_ssa_remove_op1_def(ssa, ssa_op); + zend_ssa_remove_instr(ssa, opline, ssa_op); + } + } + } + if (var->definition_phi + && var->use_chain < 0 + && var->phi_use_chain == NULL) { + zend_ssa_remove_phi(ssa, var->definition_phi); + } + return removed_ops; +} + /* This will try to replace uses of SSA variables we have determined to be constant. Not all uses * can be replaced, because some instructions don't accept constant operands or only accept them * if they have a certain type. */ @@ -1939,6 +2118,9 @@ static int replace_constant_operands(sccp_ctx *ctx) { zend_array_destroy(Z_ARR(ctx->values[i])); } Z_TYPE_INFO(ctx->values[i]) = BOT; + if ((var->use_chain < 0 && var->phi_use_chain == NULL) || var->no_val) { + removed_ops += try_remove_definition(ctx, i, var, NULL); + } continue; } else if (value_known(&ctx->values[i])) { value = &ctx->values[i]; @@ -1973,108 +2155,8 @@ static int replace_constant_operands(sccp_ctx *ctx) { } } FOREACH_USE_END(); - /* This is a basic DCE pass we run after SCCP. It only works on those instructions those result - * value(s) were determined by SCCP. It removes dead computational instructions and converts - * CV-affecting instructions into CONST ASSIGNs. This basic DCE is performed for multiple reasons: - * a) During operand replacement we eliminate FREEs. The corresponding computational instructions - * must be removed to avoid leaks. This way SCCP can run independently of the full DCE pass. - * b) The main DCE pass relies on type analysis to determine whether instructions have side-effects - * and can't be DCEd. This means that it will not be able collect all instructions rendered dead - * by SCCP, because they may have potentially side-effecting types, but the actual values are - * not. As such doing DCE here will allow us to eliminate more dead code in combination. - * c) The ordinary DCE pass cannot collect dead calls. However SCCP can result in dead calls, which - * we need to collect. */ - - if (var->definition >= 0 && value_known(&ctx->values[i])) { - zend_op *opline = &op_array->opcodes[var->definition]; - zend_ssa_op *ssa_op = &ssa->ops[var->definition]; - if (opline->opcode == ZEND_ASSIGN) { - /* Leave assigns to DCE (due to dtor effects) */ - continue; - } - - if (ssa_op->result_def == i - && ssa_op->op1_def < 0 - && ssa_op->op2_def < 0 - && var->use_chain < 0 - && var->phi_use_chain == NULL) { - if (opline->opcode == ZEND_DO_ICALL) { - /* Call instruction -> remove opcodes that are part of the call */ - zend_call_info *call; - int i; - - ZEND_ASSERT(ctx->call_map); - call = ctx->call_map[var->definition]; - ZEND_ASSERT(call); - ZEND_ASSERT(call->caller_call_opline == opline); - if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { - zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); - } - zend_ssa_remove_result_def(ssa, ssa_op); - zend_ssa_remove_instr(ssa, opline, ssa_op); - zend_ssa_remove_instr(ssa, call->caller_init_opline, - &ssa->ops[call->caller_init_opline - op_array->opcodes]); - - for (i = 0; i < call->num_args; i++) { - zend_ssa_remove_instr(ssa, call->arg_info[i].opline, - &ssa->ops[call->arg_info[i].opline - op_array->opcodes]); - } - removed_ops = call->num_args + 2; - - // TODO: remove call_info completely??? - call->callee_func = NULL; - } else { - /* Ordinary computational instruction -> remove it */ - if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { - zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); - } - zend_ssa_remove_result_def(ssa, ssa_op); - zend_ssa_remove_instr(ssa, opline, ssa_op); - removed_ops++; - } - } else if (ssa_op->op1_def == i) { - /* Compound assign or incdec -> convert to direct ASSIGN */ - - /* Destroy previous op2 */ - if (opline->op2_type == IS_CONST) { - literal_dtor(&ZEND_OP2_LITERAL(opline)); - } else if (ssa_op->op2_use >= 0) { - if (ssa_op->op2_use != ssa_op->op1_use) { - zend_ssa_unlink_use_chain(ssa, var->definition, ssa_op->op2_use); - } - ssa_op->op2_use = -1; - ssa_op->op2_use_chain = -1; - } - - /* Mark result unused, if possible */ - if (ssa_op->result_def >= 0 - && ssa->vars[ssa_op->result_def].use_chain < 0 - && ssa->vars[ssa_op->result_def].phi_use_chain == NULL) { - if (opline->result_type & (IS_TMP_VAR|IS_VAR)) { - zend_optimizer_remove_live_range_ex(op_array, opline->result.var, var->definition); - } - zend_ssa_remove_result_def(ssa, ssa_op); - opline->result_type = IS_UNUSED; - } - - /* Remove OP_DATA opcode */ - if (opline->opcode == ZEND_ASSIGN_DIM) { - removed_ops++; - zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1); - } - - /* Convert to ASSIGN */ - opline->opcode = ZEND_ASSIGN; - opline->op2_type = IS_CONST; - opline->op2.constant = zend_optimizer_add_literal(op_array, value); - Z_TRY_ADDREF_P(value); - } - } - if (var->definition_phi - && value_known(&ctx->values[i]) - && var->use_chain < 0 - && var->phi_use_chain == NULL) { - zend_ssa_remove_phi(ssa, var->definition_phi); + if (value_known(&ctx->values[i])) { + removed_ops += try_remove_definition(ctx, i, var, value); } } diff --git a/ext/opcache/tests/opt/sccp_012.phpt b/ext/opcache/tests/opt/sccp_012.phpt new file mode 100644 index 0000000..ae56057 --- /dev/null +++ b/ext/opcache/tests/opt/sccp_012.phpt @@ -0,0 +1,41 @@ +--TEST-- +SCCP 012: Conditional Constant Propagation of non-escaping object properties +--INI-- +opcache.enable=1 +opcache.enable_cli=1 +opcache.optimization_level=-1 +opcache.opt_debug_level=0x20000 +--SKIPIF-- +<?php require_once('skipif.inc'); ?> +--FILE-- +<?php +function foo() { + $o = new stdClass(); + $o->foo = 0; + $i = 1; + $c = $i < 2; + if ($c) { + $k = 2 * $i; + $o->foo = $i; + echo $o->foo; + } + $o->foo += 2; + $o->foo++; + echo $o->foo; +} +?> +--EXPECTF-- +$_main: ; (lines=1, args=0, vars=0, tmps=0) + ; (after optimizer) + ; %ssccp_012.php:1-17 +L0: RETURN int(1) + +foo: ; (lines=6, args=0, vars=0, tmps=1) + ; (after optimizer) + ; %ssccp_012.php:2-15 +L0: V0 = NEW 0 string("stdClass") +L1: DO_FCALL +L2: FREE V0 +L3: ECHO int(1) +L4: ECHO int(4) +L5: RETURN null