ref: 3ccbd4803bcc75be860dd67bb3a56b114251433b
dir: libvpx/vpx_ports/x86.h
/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef VPX_VPX_PORTS_X86_H_
#define VPX_VPX_PORTS_X86_H_
#include <stdlib.h>
#if defined(_MSC_VER)
#include <intrin.h> /* For __cpuidex, __rdtsc */
#endif
#include "vpx_config.h"
#include "vpx/vpx_integer.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef enum {
VPX_CPU_UNKNOWN = -1,
VPX_CPU_AMD,
VPX_CPU_AMD_OLD,
VPX_CPU_CENTAUR,
VPX_CPU_CYRIX,
VPX_CPU_INTEL,
VPX_CPU_NEXGEN,
VPX_CPU_NSC,
VPX_CPU_RISE,
VPX_CPU_SIS,
VPX_CPU_TRANSMETA,
VPX_CPU_TRANSMETA_OLD,
VPX_CPU_UMC,
VPX_CPU_VIA,
VPX_CPU_LAST
} vpx_cpu_t;
#if defined(__GNUC__) && __GNUC__ || defined(__ANDROID__)
#if VPX_ARCH_X86_64
#define cpuid(func, func2, ax, bx, cx, dx) \
__asm__ __volatile__("cpuid \n\t" \
: "=a"(ax), "=b"(bx), "=c"(cx), "=d"(dx) \
: "a"(func), "c"(func2));
#else
#define cpuid(func, func2, ax, bx, cx, dx) \
__asm__ __volatile__( \
"mov %%ebx, %%edi \n\t" \
"cpuid \n\t" \
"xchg %%edi, %%ebx \n\t" \
: "=a"(ax), "=D"(bx), "=c"(cx), "=d"(dx) \
: "a"(func), "c"(func2));
#endif
#elif defined(__SUNPRO_C) || \
defined(__SUNPRO_CC) /* end __GNUC__ or __ANDROID__*/
#if VPX_ARCH_X86_64
#define cpuid(func, func2, ax, bx, cx, dx) \
asm volatile( \
"xchg %rsi, %rbx \n\t" \
"cpuid \n\t" \
"movl %ebx, %edi \n\t" \
"xchg %rsi, %rbx \n\t" \
: "=a"(ax), "=D"(bx), "=c"(cx), "=d"(dx) \
: "a"(func), "c"(func2));
#else
#define cpuid(func, func2, ax, bx, cx, dx) \
asm volatile( \
"pushl %ebx \n\t" \
"cpuid \n\t" \
"movl %ebx, %edi \n\t" \
"popl %ebx \n\t" \
: "=a"(ax), "=D"(bx), "=c"(cx), "=d"(dx) \
: "a"(func), "c"(func2));
#endif
#else /* end __SUNPRO__ */
#if VPX_ARCH_X86_64
#if defined(_MSC_VER) && _MSC_VER > 1500
#define cpuid(func, func2, a, b, c, d) \
do { \
int regs[4]; \
__cpuidex(regs, func, func2); \
a = regs[0]; \
b = regs[1]; \
c = regs[2]; \
d = regs[3]; \
} while (0)
#else
#define cpuid(func, func2, a, b, c, d) \
do { \
int regs[4]; \
__cpuid(regs, func); \
a = regs[0]; \
b = regs[1]; \
c = regs[2]; \
d = regs[3]; \
} while (0)
#endif
#else
#define cpuid(func, func2, a, b, c, d) \
__asm mov eax, func __asm mov ecx, func2 __asm cpuid __asm mov a, \
eax __asm mov b, ebx __asm mov c, ecx __asm mov d, edx
#endif
#endif /* end others */
// NaCl has no support for xgetbv or the raw opcode.
#if !defined(__native_client__) && (defined(__i386__) || defined(__x86_64__))
static INLINE uint64_t xgetbv(void) {
const uint32_t ecx = 0;
uint32_t eax, edx;
// Use the raw opcode for xgetbv for compatibility with older toolchains.
__asm__ volatile(".byte 0x0f, 0x01, 0xd0\n"
: "=a"(eax), "=d"(edx)
: "c"(ecx));
return ((uint64_t)edx << 32) | eax;
}
#elif (defined(_M_X64) || defined(_M_IX86)) && defined(_MSC_FULL_VER) && \
_MSC_FULL_VER >= 160040219 // >= VS2010 SP1
#include <immintrin.h>
#define xgetbv() _xgetbv(0)
#elif defined(_MSC_VER) && defined(_M_IX86)
static INLINE uint64_t xgetbv(void) {
uint32_t eax_, edx_;
__asm {
xor ecx, ecx // ecx = 0
// Use the raw opcode for xgetbv for compatibility with older toolchains.
__asm _emit 0x0f __asm _emit 0x01 __asm _emit 0xd0
mov eax_, eax
mov edx_, edx
}
return ((uint64_t)edx_ << 32) | eax_;
}
#else
#define xgetbv() 0U // no AVX for older x64 or unrecognized toolchains.
#endif
#if defined(_MSC_VER) && _MSC_VER >= 1700
#undef NOMINMAX
#define NOMINMAX
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#if WINAPI_FAMILY_PARTITION(WINAPI_FAMILY_APP)
#define getenv(x) NULL
#endif
#endif
#define HAS_MMX 0x001
#define HAS_SSE 0x002
#define HAS_SSE2 0x004
#define HAS_SSE3 0x008
#define HAS_SSSE3 0x010
#define HAS_SSE4_1 0x020
#define HAS_AVX 0x040
#define HAS_AVX2 0x080
#define HAS_AVX512 0x100
#ifndef BIT
#define BIT(n) (1u << (n))
#endif
static INLINE int x86_simd_caps(void) {
unsigned int flags = 0;
unsigned int mask = ~0u;
unsigned int max_cpuid_val, reg_eax, reg_ebx, reg_ecx, reg_edx;
char *env;
(void)reg_ebx;
/* See if the CPU capabilities are being overridden by the environment */
env = getenv("VPX_SIMD_CAPS");
if (env && *env) return (int)strtol(env, NULL, 0);
env = getenv("VPX_SIMD_CAPS_MASK");
if (env && *env) mask = (unsigned int)strtoul(env, NULL, 0);
/* Ensure that the CPUID instruction supports extended features */
cpuid(0, 0, max_cpuid_val, reg_ebx, reg_ecx, reg_edx);
if (max_cpuid_val < 1) return 0;
/* Get the standard feature flags */
cpuid(1, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
if (reg_edx & BIT(23)) flags |= HAS_MMX;
if (reg_edx & BIT(25)) flags |= HAS_SSE; /* aka xmm */
if (reg_edx & BIT(26)) flags |= HAS_SSE2; /* aka wmt */
if (reg_ecx & BIT(0)) flags |= HAS_SSE3;
if (reg_ecx & BIT(9)) flags |= HAS_SSSE3;
if (reg_ecx & BIT(19)) flags |= HAS_SSE4_1;
// bits 27 (OSXSAVE) & 28 (256-bit AVX)
if ((reg_ecx & (BIT(27) | BIT(28))) == (BIT(27) | BIT(28))) {
// Check for OS-support of YMM state. Necessary for AVX and AVX2.
if ((xgetbv() & 0x6) == 0x6) {
flags |= HAS_AVX;
if (max_cpuid_val >= 7) {
/* Get the leaf 7 feature flags. Needed to check for AVX2 support */
cpuid(7, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
if (reg_ebx & BIT(5)) flags |= HAS_AVX2;
// bits 16 (AVX-512F) & 17 (AVX-512DQ) & 28 (AVX-512CD) &
// 30 (AVX-512BW) & 32 (AVX-512VL)
if ((reg_ebx & (BIT(16) | BIT(17) | BIT(28) | BIT(30) | BIT(31))) ==
(BIT(16) | BIT(17) | BIT(28) | BIT(30) | BIT(31))) {
// Check for OS-support of ZMM and YMM state. Necessary for AVX-512.
if ((xgetbv() & 0xe6) == 0xe6) flags |= HAS_AVX512;
}
}
}
}
(void)reg_eax; // Avoid compiler warning on unused-but-set variable.
return flags & mask;
}
// Fine-Grain Measurement Functions
//
// If you are timing a small region of code, access the timestamp counter
// (TSC) via:
//
// unsigned int start = x86_tsc_start();
// ...
// unsigned int end = x86_tsc_end();
// unsigned int diff = end - start;
//
// The start/end functions introduce a few more instructions than using
// x86_readtsc directly, but prevent the CPU's out-of-order execution from
// affecting the measurement (by having earlier/later instructions be evaluated
// in the time interval). See the white paper, "How to Benchmark Code
// Execution Times on Intel(R) IA-32 and IA-64 Instruction Set Architectures" by
// Gabriele Paoloni for more information.
//
// If you are timing a large function (CPU time > a couple of seconds), use
// x86_readtsc64 to read the timestamp counter in a 64-bit integer. The
// out-of-order leakage that can occur is minimal compared to total runtime.
static INLINE unsigned int x86_readtsc(void) {
#if defined(__GNUC__) && __GNUC__
unsigned int tsc;
__asm__ __volatile__("rdtsc\n\t" : "=a"(tsc) :);
return tsc;
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
unsigned int tsc;
asm volatile("rdtsc\n\t" : "=a"(tsc) :);
return tsc;
#else
#if VPX_ARCH_X86_64
return (unsigned int)__rdtsc();
#else
__asm rdtsc;
#endif
#endif
}
// 64-bit CPU cycle counter
static INLINE uint64_t x86_readtsc64(void) {
#if defined(__GNUC__) && __GNUC__
uint32_t hi, lo;
__asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
return ((uint64_t)hi << 32) | lo;
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
uint_t hi, lo;
asm volatile("rdtsc\n\t" : "=a"(lo), "=d"(hi));
return ((uint64_t)hi << 32) | lo;
#else
#if VPX_ARCH_X86_64
return (uint64_t)__rdtsc();
#else
__asm rdtsc;
#endif
#endif
}
// 32-bit CPU cycle counter with a partial fence against out-of-order execution.
static INLINE unsigned int x86_readtscp(void) {
#if defined(__GNUC__) && __GNUC__
unsigned int tscp;
__asm__ __volatile__("rdtscp\n\t" : "=a"(tscp) :);
return tscp;
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
unsigned int tscp;
asm volatile("rdtscp\n\t" : "=a"(tscp) :);
return tscp;
#elif defined(_MSC_VER)
unsigned int ui;
return (unsigned int)__rdtscp(&ui);
#else
#if VPX_ARCH_X86_64
return (unsigned int)__rdtscp();
#else
__asm rdtscp;
#endif
#endif
}
static INLINE unsigned int x86_tsc_start(void) {
unsigned int reg_eax, reg_ebx, reg_ecx, reg_edx;
// This call should not be removed. See function notes above.
cpuid(0, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
// Avoid compiler warnings on unused-but-set variables.
(void)reg_eax;
(void)reg_ebx;
(void)reg_ecx;
(void)reg_edx;
return x86_readtsc();
}
static INLINE unsigned int x86_tsc_end(void) {
uint32_t v = x86_readtscp();
unsigned int reg_eax, reg_ebx, reg_ecx, reg_edx;
// This call should not be removed. See function notes above.
cpuid(0, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
// Avoid compiler warnings on unused-but-set variables.
(void)reg_eax;
(void)reg_ebx;
(void)reg_ecx;
(void)reg_edx;
return v;
}
#if defined(__GNUC__) && __GNUC__
#define x86_pause_hint() __asm__ __volatile__("pause \n\t")
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
#define x86_pause_hint() asm volatile("pause \n\t")
#else
#if VPX_ARCH_X86_64
#define x86_pause_hint() _mm_pause();
#else
#define x86_pause_hint() __asm pause
#endif
#endif
#if defined(__GNUC__) && __GNUC__
static void x87_set_control_word(unsigned short mode) {
__asm__ __volatile__("fldcw %0" : : "m"(*&mode));
}
static unsigned short x87_get_control_word(void) {
unsigned short mode;
__asm__ __volatile__("fstcw %0\n\t" : "=m"(*&mode) :);
return mode;
}
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
static void x87_set_control_word(unsigned short mode) {
asm volatile("fldcw %0" : : "m"(*&mode));
}
static unsigned short x87_get_control_word(void) {
unsigned short mode;
asm volatile("fstcw %0\n\t" : "=m"(*&mode) :);
return mode;
}
#elif VPX_ARCH_X86_64
/* No fldcw intrinsics on Windows x64, punt to external asm */
extern void vpx_winx64_fldcw(unsigned short mode);
extern unsigned short vpx_winx64_fstcw(void);
#define x87_set_control_word vpx_winx64_fldcw
#define x87_get_control_word vpx_winx64_fstcw
#else
static void x87_set_control_word(unsigned short mode) {
__asm { fldcw mode }
}
static unsigned short x87_get_control_word(void) {
unsigned short mode;
__asm { fstcw mode }
return mode;
}
#endif
static INLINE unsigned int x87_set_double_precision(void) {
unsigned int mode = x87_get_control_word();
// Intel 64 and IA-32 Architectures Developer's Manual: Vol. 1
// https://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-1-manual.pdf
// 8.1.5.2 Precision Control Field
// Bits 8 and 9 (0x300) of the x87 FPU Control Word ("Precision Control")
// determine the number of bits used in floating point calculations. To match
// later SSE instructions restrict x87 operations to Double Precision (0x200).
// Precision PC Field
// Single Precision (24-Bits) 00B
// Reserved 01B
// Double Precision (53-Bits) 10B
// Extended Precision (64-Bits) 11B
x87_set_control_word((mode & ~0x300) | 0x200);
return mode;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // VPX_VPX_PORTS_X86_H_