Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/* compile-time and runtime tests for whether to use Power ISA-specific
* extensions */
#include "ppc.h"
#include "mozilla/Unused.h"
#include <stdio.h>
#include <stdlib.h>
#if defined(XP_LINUX)
// Use the getauxval() function if available.
// ARCH_3_00 wasn't defined until glibc 2.23, so include just in case.
# include <sys/auxv.h>
# ifndef PPC_FEATURE2_ARCH_3_00
# define PPC_FEATURE2_ARCH_3_00 0x00800000
# endif
#endif
const unsigned PPC_FLAG_VMX = 1;
const unsigned PPC_FLAG_VSX = 2;
const unsigned PPC_FLAG_VSX3 = 4;
static signed get_ppc_cpu_flags(void) {
// This could be expensive, so cache the result.
static signed cpu_flags = -1;
if (cpu_flags > -1) { // already checked
return cpu_flags;
}
cpu_flags = 0;
#if defined(XP_LINUX)
// Try getauxval().
unsigned long int cap = getauxval(AT_HWCAP);
unsigned long int cap2 = getauxval(AT_HWCAP2);
if (cap & PPC_FEATURE_HAS_ALTIVEC) {
cpu_flags |= PPC_FLAG_VMX;
}
if (cap & PPC_FEATURE_HAS_VSX) {
cpu_flags |= PPC_FLAG_VSX;
}
if (cap2 & PPC_FEATURE2_ARCH_3_00) {
cpu_flags |= PPC_FLAG_VSX3;
}
#else
// Non-Linux detection here. Currently, on systems other than Linux,
// no CPU SIMD features will be detected.
#endif
return cpu_flags;
}
namespace mozilla {
namespace ppc_private {
bool vmx_enabled = !!(get_ppc_cpu_flags() & PPC_FLAG_VMX);
bool vsx_enabled = !!(get_ppc_cpu_flags() & PPC_FLAG_VSX);
bool vsx3_enabled = !!(get_ppc_cpu_flags() & PPC_FLAG_VSX3);
} // namespace ppc_private
} // namespace mozilla