Coverage Report

Created: 2025-06-13 06:43

/src/php-src/Zend/Optimizer/compact_vars.c
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Count
Source (jump to first uncovered line)
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/*
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   +----------------------------------------------------------------------+
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   | Zend Engine, Removing unused variables                               |
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   +----------------------------------------------------------------------+
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   | Copyright (c) The PHP Group                                          |
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   +----------------------------------------------------------------------+
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   | This source file is subject to version 3.01 of the PHP license,      |
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   | that is bundled with this package in the file LICENSE, and is        |
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   | available through the world-wide-web at the following url:           |
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   | https://www.php.net/license/3_01.txt                                 |
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   | If you did not receive a copy of the PHP license and are unable to   |
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   | obtain it through the world-wide-web, please send a note to          |
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   | license@php.net so we can mail you a copy immediately.               |
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   +----------------------------------------------------------------------+
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   | Authors: Nikita Popov <nikic@php.net>                                |
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   +----------------------------------------------------------------------+
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*/
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#include "Optimizer/zend_optimizer_internal.h"
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#include "zend_bitset.h"
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#include "zend_observer.h"
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/* This pass removes all CVs and temporaries that are completely unused. It does *not* merge any CVs or TMPs.
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 * This pass does not operate on SSA form anymore. */
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109k
void zend_optimizer_compact_vars(zend_op_array *op_array) {
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109k
  int i;
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109k
  ALLOCA_FLAG(use_heap1);
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109k
  ALLOCA_FLAG(use_heap2);
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109k
  uint32_t used_vars_len = zend_bitset_len(op_array->last_var + op_array->T);
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109k
  zend_bitset used_vars = ZEND_BITSET_ALLOCA(used_vars_len, use_heap1);
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109k
  uint32_t *vars_map = do_alloca((op_array->last_var + op_array->T) * sizeof(uint32_t), use_heap2);
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109k
  uint32_t num_cvs, num_tmps;
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  /* Determine which CVs are used */
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109k
  zend_bitset_clear(used_vars, used_vars_len);
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2.61M
  for (i = 0; i < op_array->last; i++) {
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2.50M
    zend_op *opline = &op_array->opcodes[i];
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2.50M
    if (opline->op1_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
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1.46M
      zend_bitset_incl(used_vars, VAR_NUM(opline->op1.var));
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1.46M
    }
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2.50M
    if (opline->op2_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
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616k
      zend_bitset_incl(used_vars, VAR_NUM(opline->op2.var));
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616k
    }
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2.50M
    if (opline->result_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
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1.28M
      zend_bitset_incl(used_vars, VAR_NUM(opline->result.var));
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1.28M
      if (opline->opcode == ZEND_ROPE_INIT) {
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26.0k
        uint32_t num = ((opline->extended_value * sizeof(zend_string*)) + (sizeof(zval) - 1)) / sizeof(zval);
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214k
        while (num > 1) {
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188k
          num--;
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188k
          zend_bitset_incl(used_vars, VAR_NUM(opline->result.var) + num);
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188k
        }
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26.0k
      }
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1.28M
    }
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2.50M
  }
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109k
  num_cvs = 0;
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547k
  for (i = 0; i < op_array->last_var; i++) {
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437k
    if (zend_bitset_in(used_vars, i)) {
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434k
      vars_map[i] = num_cvs++;
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434k
    } else {
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3.93k
      vars_map[i] = (uint32_t) -1;
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3.93k
    }
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437k
  }
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109k
  num_tmps = 0;
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425k
  for (i = op_array->last_var; i < op_array->last_var + op_array->T; i++) {
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316k
    if (zend_bitset_in(used_vars, i)) {
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316k
      vars_map[i] = num_cvs + num_tmps++;
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316k
    } else {
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0
      vars_map[i] = (uint32_t) -1;
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0
    }
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316k
  }
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109k
  free_alloca(used_vars, use_heap1);
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109k
  if (num_cvs == op_array->last_var && num_tmps == op_array->T) {
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106k
    free_alloca(vars_map, use_heap2);
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106k
    return;
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106k
  }
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2.68k
  ZEND_ASSERT(num_cvs <= op_array->last_var);
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2.68k
  ZEND_ASSERT(num_tmps <= op_array->T);
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  /* Update CV and TMP references in opcodes */
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108k
  for (i = 0; i < op_array->last; i++) {
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106k
    zend_op *opline = &op_array->opcodes[i];
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106k
    if (opline->op1_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
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69.1k
      opline->op1.var = NUM_VAR(vars_map[VAR_NUM(opline->op1.var)]);
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69.1k
    }
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106k
    if (opline->op2_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
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28.2k
      opline->op2.var = NUM_VAR(vars_map[VAR_NUM(opline->op2.var)]);
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28.2k
    }
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106k
    if (opline->result_type & (IS_CV|IS_VAR|IS_TMP_VAR)) {
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61.4k
      opline->result.var = NUM_VAR(vars_map[VAR_NUM(opline->result.var)]);
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61.4k
    }
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106k
  }
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  /* Update CV name table */
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2.68k
  if (num_cvs != op_array->last_var) {
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2.68k
    if (num_cvs) {
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2.26k
      zend_string **names = safe_emalloc(sizeof(zend_string *), num_cvs, 0);
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18.4k
      for (i = 0; i < op_array->last_var; i++) {
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16.1k
        if (vars_map[i] != (uint32_t) -1) {
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12.8k
          names[vars_map[i]] = op_array->vars[i];
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12.8k
        } else {
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3.32k
          zend_string_release_ex(op_array->vars[i], 0);
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3.32k
        }
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16.1k
      }
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2.26k
      efree(op_array->vars);
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2.26k
      op_array->vars = names;
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2.26k
    } else {
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1.02k
      for (i = 0; i < op_array->last_var; i++) {
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607
        zend_string_release_ex(op_array->vars[i], 0);
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607
      }
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421
      efree(op_array->vars);
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421
      op_array->vars = NULL;
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421
    }
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2.68k
    op_array->last_var = num_cvs;
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2.68k
  }
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2.68k
  op_array->T = num_tmps + ZEND_OBSERVER_ENABLED; // reserve last temporary for observers if enabled
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2.68k
  free_alloca(vars_map, use_heap2);
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2.68k
}