Coverage Report

Created: 2025-06-13 06:43

/src/php-src/Zend/zend_cpuinfo.c
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Source (jump to first uncovered line)
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/*
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   +----------------------------------------------------------------------+
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   | Zend Engine                                                          |
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   +----------------------------------------------------------------------+
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   | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
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   +----------------------------------------------------------------------+
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   | This source file is subject to version 2.00 of the Zend 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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   | http://www.zend.com/license/2_00.txt.                                |
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   | If you did not receive a copy of the Zend 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@zend.com so we can mail you a copy immediately.              |
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   +----------------------------------------------------------------------+
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   | Authors: Xinchen Hui <xinchen.h@zend.com>                            |
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   +----------------------------------------------------------------------+
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*/
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#include "zend_cpuinfo.h"
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typedef struct _zend_cpu_info {
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  uint32_t eax;
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  uint32_t ebx;
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  uint32_t ecx;
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  uint32_t edx;
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  uint32_t initialized;
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} zend_cpu_info;
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static zend_cpu_info cpuinfo = {0};
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#if (defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__))
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# if defined(HAVE_CPUID_H) && defined(HAVE_CPUID_COUNT) /* use cpuid.h functions */
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#  include <cpuid.h>
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static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
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  __cpuid_count(func, subfunc, cpuinfo->eax, cpuinfo->ebx, cpuinfo->ecx, cpuinfo->edx);
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}
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# else /* use inline asm */
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static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
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#  if defined(__i386__) && (defined(__pic__) || defined(__PIC__))
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  /* PIC on i386 uses %ebx, so preserve it. */
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  __asm__ __volatile__ (
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    "pushl  %%ebx\n"
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    "cpuid\n"
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    "mov    %%ebx,%1\n"
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    "popl   %%ebx"
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    : "=a"(cpuinfo->eax), "=r"(cpuinfo->ebx), "=c"(cpuinfo->ecx), "=d"(cpuinfo->edx)
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    : "a"(func), "c"(subfunc)
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  );
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#  else
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  __asm__ __volatile__ (
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    "cpuid"
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    : "=a"(cpuinfo->eax), "=b"(cpuinfo->ebx), "=c"(cpuinfo->ecx), "=d"(cpuinfo->edx)
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    : "a"(func), "c"(subfunc)
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  );
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#  endif
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}
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# endif
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#elif defined(_MSC_VER) && !defined(__clang__) && (defined(_M_X64) || defined(_M_IX86)) /* use MSVC __cpuidex intrin */
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# include <intrin.h>
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static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
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  int regs[4];
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  __cpuidex(regs, func, subfunc);
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  cpuinfo->eax = regs[0];
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  cpuinfo->ebx = regs[1];
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  cpuinfo->ecx = regs[2];
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  cpuinfo->edx = regs[3];
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}
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#else /* fall back to zero */
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static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
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  cpuinfo->eax = 0;
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}
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#endif
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#if defined(__i386__) || defined(__x86_64__) || defined(_M_X64) || defined(_M_IX86)
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/* Function based on compiler-rt implementation. */
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static unsigned get_xcr0_eax(void) {
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# if defined(__GNUC__) || defined(__clang__)
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  // Check xgetbv; this uses a .byte sequence instead of the instruction
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  // directly because older assemblers do not include support for xgetbv and
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  // there is no easy way to conditionally compile based on the assembler used.
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  unsigned eax, edx;
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  __asm__(".byte 0x0f, 0x01, 0xd0" : "=a"(eax), "=d"(edx) : "c"(0));
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  return eax;
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# elif defined(ZEND_WIN32) && defined(_XCR_XFEATURE_ENABLED_MASK)
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  return _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
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# else
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  return 0;
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# endif
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}
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static bool is_avx_supported(void) {
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  if (!(cpuinfo.ecx & ZEND_CPU_FEATURE_AVX)) {
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    /* No support for AVX */
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0
    return 0;
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0
  }
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  if (!(cpuinfo.ecx & ZEND_CPU_FEATURE_OSXSAVE)) {
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    /* The operating system does not support XSAVE. */
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    return 0;
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0
  }
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  if ((get_xcr0_eax() & 0x6) != 0x6) {
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    /* XCR0 SSE and AVX bits must be set. */
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    return 0;
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0
  }
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  return 1;
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}
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#else
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static bool is_avx_supported(void) {
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  return 0;
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}
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#endif
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void zend_cpu_startup(void)
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{
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  if (!cpuinfo.initialized) {
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    zend_cpu_info ebx;
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    int max_feature;
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    cpuinfo.initialized = 1;
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    __zend_cpuid(0, 0, &cpuinfo);
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    max_feature = cpuinfo.eax;
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    if (max_feature == 0) {
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      return;
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0
    }
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    __zend_cpuid(1, 0, &cpuinfo);
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    /* for avx2 */
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    if (max_feature >= 7) {
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      __zend_cpuid(7, 0, &ebx);
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      cpuinfo.ebx = ebx.ebx;
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    } else {
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      cpuinfo.ebx = 0;
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0
    }
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    if (!is_avx_supported()) {
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      cpuinfo.edx &= ~ZEND_CPU_FEATURE_AVX;
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      cpuinfo.ebx &= ~(ZEND_CPU_FEATURE_AVX2 & ~ZEND_CPU_EBX_MASK);
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0
    }
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  }
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}
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86.5k
ZEND_API int zend_cpu_supports(zend_cpu_feature feature) {
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86.5k
  ZEND_ASSERT(cpuinfo.initialized);
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  if (feature & ZEND_CPU_EDX_MASK) {
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    return (cpuinfo.edx & (feature & ~ZEND_CPU_EDX_MASK));
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86.5k
  } else if (feature & ZEND_CPU_EBX_MASK) {
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    return (cpuinfo.ebx & (feature & ~ZEND_CPU_EBX_MASK));
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  } else {
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43.2k
    return (cpuinfo.ecx & feature);
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  }
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86.5k
}