ref: ec60da4961b4acff96631e7b99c90a0f4500dbed
dir: /sys/src/cmd/audio/libFLAC/cpu.c/
/* libFLAC - Free Lossless Audio Codec library
* Copyright (C) 2001-2009 Josh Coalson
* Copyright (C) 2011-2014 Xiph.Org Foundation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the Xiph.org Foundation nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "private/cpu.h"
#include "private/memory.h"
#include <stdlib.h>
#ifdef DEBUG
# include <stdio.h>
#endif
#if defined FLAC__CPU_IA32
# include <signal.h>
static void disable_sse(FLAC__CPUInfo *info)
{
info->ia32.sse = false;
info->ia32.sse2 = false;
info->ia32.sse3 = false;
info->ia32.ssse3 = false;
info->ia32.sse41 = false;
info->ia32.sse42 = false;
}
static void disable_avx(FLAC__CPUInfo *info)
{
info->ia32.avx = false;
info->ia32.avx2 = false;
info->ia32.fma = false;
}
#elif defined FLAC__CPU_X86_64
static void disable_avx(FLAC__CPUInfo *info)
{
info->x86.avx = false;
info->x86.avx2 = false;
info->x86.fma = false;
}
#endif
#if defined (__NetBSD__) || defined(__OpenBSD__)
#include <sys/param.h>
#include <sys/sysctl.h>
#include <machine/cpu.h>
#endif
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
#include <sys/types.h>
#include <sys/sysctl.h>
#endif
#if defined(__APPLE__)
/* how to get sysctlbyname()? */
#endif
#ifdef FLAC__CPU_IA32
/* these are flags in EDX of CPUID AX=00000001 */
static const unsigned FLAC__CPUINFO_IA32_CPUID_CMOV = 0x00008000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_MMX = 0x00800000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_FXSR = 0x01000000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE = 0x02000000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE2 = 0x04000000;
#endif
/* these are flags in ECX of CPUID AX=00000001 */
static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE3 = 0x00000001;
static const unsigned FLAC__CPUINFO_IA32_CPUID_SSSE3 = 0x00000200;
static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE41 = 0x00080000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE42 = 0x00100000;
#if defined FLAC__AVX_SUPPORTED
/* these are flags in ECX of CPUID AX=00000001 */
static const unsigned FLAC__CPUINFO_IA32_CPUID_OSXSAVE = 0x08000000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_AVX = 0x10000000;
static const unsigned FLAC__CPUINFO_IA32_CPUID_FMA = 0x00001000;
/* these are flags in EBX of CPUID AX=00000007 */
static const unsigned FLAC__CPUINFO_IA32_CPUID_AVX2 = 0x00000020;
#endif
/*
* Extra stuff needed for detection of OS support for SSE on IA-32
*/
#if defined(FLAC__CPU_IA32) && !defined FLAC__NO_ASM && (defined FLAC__HAS_NASM || defined FLAC__HAS_X86INTRIN) && !defined FLAC__NO_SSE_OS && !defined FLAC__SSE_OS
# if defined(__linux__)
/*
* If the OS doesn't support SSE, we will get here with a SIGILL. We
* modify the return address to jump over the offending SSE instruction
* and also the operation following it that indicates the instruction
* executed successfully. In this way we use no global variables and
* stay thread-safe.
*
* 3 + 3 + 6:
* 3 bytes for "xorps xmm0,xmm0"
* 3 bytes for estimate of how long the follwing "inc var" instruction is
* 6 bytes extra in case our estimate is wrong
* 12 bytes puts us in the NOP "landing zone"
*/
# include <sys/ucontext.h>
static void sigill_handler_sse_os(int signal, siginfo_t *si, void *uc)
{
(void)signal, (void)si;
((ucontext_t*)uc)->uc_mcontext.gregs[14/*REG_EIP*/] += 3 + 3 + 6;
}
# elif defined(_MSC_VER)
# include <windows.h>
# endif
#endif
void FLAC__cpu_info(FLAC__CPUInfo *info)
{
/*
* IA32-specific
*/
#ifdef FLAC__CPU_IA32
FLAC__bool ia32_fxsr = false;
FLAC__bool ia32_osxsave = false;
(void) ia32_fxsr; (void) ia32_osxsave; /* to avoid warnings about unused variables */
memset(info, 0, sizeof(*info));
info->type = FLAC__CPUINFO_TYPE_IA32;
#if !defined FLAC__NO_ASM && (defined FLAC__HAS_NASM || defined FLAC__HAS_X86INTRIN)
info->use_asm = true; /* we assume a minimum of 80386 with FLAC__CPU_IA32 */
#ifdef FLAC__HAS_X86INTRIN
if(!FLAC__cpu_have_cpuid_x86())
return;
#else
if(!FLAC__cpu_have_cpuid_asm_ia32())
return;
#endif
{
/* http://www.sandpile.org/x86/cpuid.htm */
#ifdef FLAC__HAS_X86INTRIN
FLAC__uint32 flags_eax, flags_ebx, flags_ecx, flags_edx;
FLAC__cpu_info_x86(1, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);
#else
FLAC__uint32 flags_ecx, flags_edx;
FLAC__cpu_info_asm_ia32(&flags_edx, &flags_ecx);
#endif
info->ia32.cmov = (flags_edx & FLAC__CPUINFO_IA32_CPUID_CMOV )? true : false;
info->ia32.mmx = (flags_edx & FLAC__CPUINFO_IA32_CPUID_MMX )? true : false;
ia32_fxsr = (flags_edx & FLAC__CPUINFO_IA32_CPUID_FXSR )? true : false;
info->ia32.sse = (flags_edx & FLAC__CPUINFO_IA32_CPUID_SSE )? true : false;
info->ia32.sse2 = (flags_edx & FLAC__CPUINFO_IA32_CPUID_SSE2 )? true : false;
info->ia32.sse3 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE3 )? true : false;
info->ia32.ssse3 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSSE3)? true : false;
info->ia32.sse41 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE41)? true : false;
info->ia32.sse42 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE42)? true : false;
#if defined FLAC__HAS_X86INTRIN && defined FLAC__AVX_SUPPORTED
ia32_osxsave = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_OSXSAVE)? true : false;
info->ia32.avx = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_AVX )? true : false;
info->ia32.fma = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_FMA )? true : false;
FLAC__cpu_info_x86(7, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);
info->ia32.avx2 = (flags_ebx & FLAC__CPUINFO_IA32_CPUID_AVX2 )? true : false;
#endif
}
#ifdef DEBUG
fprintf(stderr, "CPU info (IA-32):\n");
fprintf(stderr, " CMOV ....... %c\n", info->ia32.cmov ? 'Y' : 'n');
fprintf(stderr, " MMX ........ %c\n", info->ia32.mmx ? 'Y' : 'n');
fprintf(stderr, " SSE ........ %c\n", info->ia32.sse ? 'Y' : 'n');
fprintf(stderr, " SSE2 ....... %c\n", info->ia32.sse2 ? 'Y' : 'n');
fprintf(stderr, " SSE3 ....... %c\n", info->ia32.sse3 ? 'Y' : 'n');
fprintf(stderr, " SSSE3 ...... %c\n", info->ia32.ssse3 ? 'Y' : 'n');
fprintf(stderr, " SSE41 ...... %c\n", info->ia32.sse41 ? 'Y' : 'n');
fprintf(stderr, " SSE42 ...... %c\n", info->ia32.sse42 ? 'Y' : 'n');
# if defined FLAC__HAS_X86INTRIN && defined FLAC__AVX_SUPPORTED
fprintf(stderr, " AVX ........ %c\n", info->ia32.avx ? 'Y' : 'n');
fprintf(stderr, " FMA ........ %c\n", info->ia32.fma ? 'Y' : 'n');
fprintf(stderr, " AVX2 ....... %c\n", info->ia32.avx2 ? 'Y' : 'n');
# endif
#endif
/*
* now have to check for OS support of SSE instructions
*/
if(info->ia32.sse) {
#if defined FLAC__NO_SSE_OS
/* assume user knows better than us; turn it off */
disable_sse(info);
#elif defined FLAC__SSE_OS
/* assume user knows better than us; leave as detected above */
#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) || defined(__APPLE__)
int sse = 0;
size_t len;
/* at least one of these must work: */
len = sizeof(sse); sse = sse || (sysctlbyname("hw.instruction_sse", &sse, &len, NULL, 0) == 0 && sse);
len = sizeof(sse); sse = sse || (sysctlbyname("hw.optional.sse" , &sse, &len, NULL, 0) == 0 && sse); /* __APPLE__ ? */
if(!sse)
disable_sse(info);
#elif defined(__NetBSD__) || defined (__OpenBSD__)
# if __NetBSD_Version__ >= 105250000 || (defined __OpenBSD__)
int val = 0, mib[2] = { CTL_MACHDEP, CPU_SSE };
size_t len = sizeof(val);
if(sysctl(mib, 2, &val, &len, NULL, 0) < 0 || !val)
disable_sse(info);
else { /* double-check SSE2 */
mib[1] = CPU_SSE2;
len = sizeof(val);
if(sysctl(mib, 2, &val, &len, NULL, 0) < 0 || !val) {
disable_sse(info);
info->ia32.sse = true;
}
}
# else
disable_sse(info);
# endif
#elif defined(__linux__)
int sse = 0;
struct sigaction sigill_save;
struct sigaction sigill_sse;
sigill_sse.sa_sigaction = sigill_handler_sse_os;
__sigemptyset(&sigill_sse.sa_mask);
sigill_sse.sa_flags = SA_SIGINFO | SA_RESETHAND; /* SA_RESETHAND just in case our SIGILL return jump breaks, so we don't get stuck in a loop */
if(0 == sigaction(SIGILL, &sigill_sse, &sigill_save))
{
/* http://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html */
/* see sigill_handler_sse_os() for an explanation of the following: */
asm volatile (
"xorps %%xmm0,%%xmm0\n\t" /* will cause SIGILL if unsupported by OS */
"incl %0\n\t" /* SIGILL handler will jump over this */
/* landing zone */
"nop\n\t" /* SIGILL jump lands here if "inc" is 9 bytes */
"nop\n\t"
"nop\n\t"
"nop\n\t"
"nop\n\t"
"nop\n\t"
"nop\n\t" /* SIGILL jump lands here if "inc" is 3 bytes (expected) */
"nop\n\t"
"nop" /* SIGILL jump lands here if "inc" is 1 byte */
: "=r"(sse)
: "0"(sse)
);
sigaction(SIGILL, &sigill_save, NULL);
}
if(!sse)
disable_sse(info);
#elif defined(_MSC_VER)
__try {
__asm {
xorps xmm0,xmm0
}
}
__except(EXCEPTION_EXECUTE_HANDLER) {
if (_exception_code() == STATUS_ILLEGAL_INSTRUCTION)
disable_sse(info);
}
#elif defined(__GNUC__) /* MinGW goes here */
int sse = 0;
/* Based on the idea described in Agner Fog's manual "Optimizing subroutines in assembly language" */
/* In theory, not guaranteed to detect lack of OS SSE support on some future Intel CPUs, but in practice works (see the aforementioned manual) */
if (ia32_fxsr) {
struct {
FLAC__uint32 buff[128];
} __attribute__((aligned(16))) fxsr;
FLAC__uint32 old_val, new_val;
asm volatile ("fxsave %0" : "=m" (fxsr) : "m" (fxsr));
old_val = fxsr.buff[50];
fxsr.buff[50] ^= 0x0013c0de; /* change value in the buffer */
asm volatile ("fxrstor %0" : "=m" (fxsr) : "m" (fxsr)); /* try to change SSE register */
fxsr.buff[50] = old_val; /* restore old value in the buffer */
asm volatile ("fxsave %0 " : "=m" (fxsr) : "m" (fxsr)); /* old value will be overwritten if SSE register was changed */
new_val = fxsr.buff[50]; /* == old_val if FXRSTOR didn't change SSE register and (old_val ^ 0x0013c0de) otherwise */
fxsr.buff[50] = old_val; /* again restore old value in the buffer */
asm volatile ("fxrstor %0" : "=m" (fxsr) : "m" (fxsr)); /* restore old values of registers */
if ((old_val^new_val) == 0x0013c0de)
sse = 1;
}
if(!sse)
disable_sse(info);
#else
/* no way to test, disable to be safe */
disable_sse(info);
#endif
#ifdef DEBUG
fprintf(stderr, " SSE OS sup . %c\n", info->ia32.sse ? 'Y' : 'n');
#endif
}
else /* info->ia32.sse == false */
disable_sse(info);
/*
* now have to check for OS support of AVX instructions
*/
if(info->ia32.avx && ia32_osxsave) {
FLAC__uint32 ecr = FLAC__cpu_xgetbv_x86();
if ((ecr & 0x6) != 0x6)
disable_avx(info);
#ifdef DEBUG
fprintf(stderr, " AVX OS sup . %c\n", info->ia32.avx ? 'Y' : 'n');
#endif
}
else /* no OS AVX support*/
disable_avx(info);
#else
info->use_asm = false;
#endif
/*
* x86-64-specific
*/
#elif defined FLAC__CPU_X86_64
FLAC__bool x86_osxsave = false;
(void) x86_osxsave; /* to avoid warnings about unused variables */
memset(info, 0, sizeof(*info));
info->type = FLAC__CPUINFO_TYPE_X86_64;
#if !defined FLAC__NO_ASM && defined FLAC__HAS_X86INTRIN
info->use_asm = true;
{
/* http://www.sandpile.org/x86/cpuid.htm */
FLAC__uint32 flags_eax, flags_ebx, flags_ecx, flags_edx;
FLAC__cpu_info_x86(1, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);
info->x86.sse3 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE3 )? true : false;
info->x86.ssse3 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSSE3)? true : false;
info->x86.sse41 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE41)? true : false;
info->x86.sse42 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE42)? true : false;
#if defined FLAC__AVX_SUPPORTED
x86_osxsave = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_OSXSAVE)? true : false;
info->x86.avx = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_AVX )? true : false;
info->x86.fma = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_FMA )? true : false;
FLAC__cpu_info_x86(7, &flags_eax, &flags_ebx, &flags_ecx, &flags_edx);
info->x86.avx2 = (flags_ebx & FLAC__CPUINFO_IA32_CPUID_AVX2 )? true : false;
#endif
}
#ifdef DEBUG
fprintf(stderr, "CPU info (x86-64):\n");
fprintf(stderr, " SSE3 ....... %c\n", info->x86.sse3 ? 'Y' : 'n');
fprintf(stderr, " SSSE3 ...... %c\n", info->x86.ssse3 ? 'Y' : 'n');
fprintf(stderr, " SSE41 ...... %c\n", info->x86.sse41 ? 'Y' : 'n');
fprintf(stderr, " SSE42 ...... %c\n", info->x86.sse42 ? 'Y' : 'n');
# if defined FLAC__AVX_SUPPORTED
fprintf(stderr, " AVX ........ %c\n", info->x86.avx ? 'Y' : 'n');
fprintf(stderr, " FMA ........ %c\n", info->x86.fma ? 'Y' : 'n');
fprintf(stderr, " AVX2 ....... %c\n", info->x86.avx2 ? 'Y' : 'n');
# endif
#endif
/*
* now have to check for OS support of AVX instructions
*/
if(info->x86.avx && x86_osxsave) {
FLAC__uint32 ecr = FLAC__cpu_xgetbv_x86();
if ((ecr & 0x6) != 0x6)
disable_avx(info);
#ifdef DEBUG
fprintf(stderr, " AVX OS sup . %c\n", info->x86.avx ? 'Y' : 'n');
#endif
}
else /* no OS AVX support*/
disable_avx(info);
#else
info->use_asm = false;
#endif
/*
* unknown CPU
*/
#else
info->type = FLAC__CPUINFO_TYPE_UNKNOWN;
info->use_asm = false;
#endif
}
#if (defined FLAC__CPU_IA32 || defined FLAC__CPU_X86_64) && defined FLAC__HAS_X86INTRIN
#if defined _MSC_VER
#include <intrin.h> /* for __cpuid() and _xgetbv() */
#elif defined __GNUC__ && defined HAVE_CPUID_H
#include <cpuid.h> /* for __get_cpuid() and __get_cpuid_max() */
#endif
FLAC__uint32 FLAC__cpu_have_cpuid_x86(void)
{
#ifdef FLAC__CPU_X86_64
return 1;
#else
# if defined _MSC_VER || defined __INTEL_COMPILER /* Do they support CPUs w/o CPUID support (or OSes that work on those CPUs)? */
FLAC__uint32 flags1, flags2;
__asm {
pushfd
pushfd
pop eax
mov flags1, eax
xor eax, 0x200000
push eax
popfd
pushfd
pop eax
mov flags2, eax
popfd
}
if (((flags1^flags2) & 0x200000) != 0)
return 1;
else
return 0;
# elif defined __GNUC__ && defined HAVE_CPUID_H
if (__get_cpuid_max(0, 0) != 0)
return 1;
else
return 0;
# else
return 0;
# endif
#endif
}
void FLAC__cpu_info_x86(FLAC__uint32 level, FLAC__uint32 *eax, FLAC__uint32 *ebx, FLAC__uint32 *ecx, FLAC__uint32 *edx)
{
#if defined _MSC_VER || defined __INTEL_COMPILER
int cpuinfo[4];
int ext = level & 0x80000000;
__cpuid(cpuinfo, ext);
if((unsigned)cpuinfo[0] < level) {
*eax = *ebx = *ecx = *edx = 0;
return;
}
#if defined FLAC__AVX_SUPPORTED
__cpuidex(cpuinfo, level, 0); /* for AVX2 detection */
#else
__cpuid(cpuinfo, level); /* some old compilers don't support __cpuidex */
#endif
*eax = cpuinfo[0]; *ebx = cpuinfo[1]; *ecx = cpuinfo[2]; *edx = cpuinfo[3];
#elif defined __GNUC__ && defined HAVE_CPUID_H
FLAC__uint32 ext = level & 0x80000000;
__cpuid(ext, *eax, *ebx, *ecx, *edx);
if (*eax < level) {
*eax = *ebx = *ecx = *edx = 0;
return;
}
__cpuid_count(level, 0, *eax, *ebx, *ecx, *edx);
#else
*eax = *ebx = *ecx = *edx = 0;
#endif
}
FLAC__uint32 FLAC__cpu_xgetbv_x86(void)
{
#if (defined _MSC_VER || defined __INTEL_COMPILER) && defined FLAC__AVX_SUPPORTED
return (FLAC__uint32)_xgetbv(0);
#elif defined __GNUC__
FLAC__uint32 lo, hi;
asm volatile (".byte 0x0f, 0x01, 0xd0" : "=a"(lo), "=d"(hi) : "c" (0));
return lo;
#else
return 0;
#endif
}
#endif /* (FLAC__CPU_IA32 || FLAC__CPU_X86_64) && FLAC__HAS_X86INTRIN */