SSE.h
/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* compile-time and runtime tests for whether to use SSE instructions */
#ifndef mozilla_SSE_h_
#define mozilla_SSE_h_
// for definition of MFBT_DATA
#include "mozilla/Types.h"
/**
* The public interface of this header consists of a set of macros and
* functions for Intel CPU features.
*
* DETECTING ISA EXTENSIONS
* ========================
*
* This header provides the following functions for determining whether the
* current CPU supports a particular instruction set extension:
*
* mozilla::supports_mmx
* mozilla::supports_sse
* mozilla::supports_sse2
* mozilla::supports_sse3
* mozilla::supports_ssse3
* mozilla::supports_sse4a
* mozilla::supports_sse4_1
* mozilla::supports_sse4_2
*
* If you're writing code using inline assembly, you should guard it with a
* call to one of these functions. For instance:
*
* if (mozilla::supports_sse2()) {
* asm(" ... ");
* }
* else {
* ...
* }
*
* Note that these functions depend on cpuid intrinsics only available in gcc
* 4.3 or later and MSVC 8.0 (Visual C++ 2005) or later, so they return false
* in older compilers. (This could be fixed by replacing the code with inline
* assembly.)
*
*
* USING INTRINSICS
* ================
*
* This header also provides support for coding using CPU intrinsics.
*
* For each mozilla::supports_abc function, we define a MOZILLA_MAY_SUPPORT_ABC
* macro which indicates that the target/compiler combination we're using is
* compatible with the ABC extension. For instance, x86_64 with MSVC 2003 is
* compatible with SSE2 but not SSE3, since although there exist x86_64 CPUs
* with SSE3 support, MSVC 2003 only supports through SSE2.
*
* Until gcc fixes #pragma target [1] [2] or our x86 builds require SSE2,
* you'll need to separate code using intrinsics into a file separate from your
* regular code. Here's the recommended pattern:
*
* #ifdef MOZILLA_MAY_SUPPORT_ABC
* namespace mozilla {
* namespace ABC {
* void foo();
* }
* }
* #endif
*
* void foo() {
* #ifdef MOZILLA_MAY_SUPPORT_ABC
* if (mozilla::supports_abc()) {
* mozilla::ABC::foo(); // in a separate file
* return;
* }
* #endif
*
* foo_unvectorized();
* }
*
* You'll need to define mozilla::ABC::foo() in a separate file and add the
* -mabc flag when using gcc.
*
* [1] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39787 and
* [2] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41201 being fixed.
*
*/
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
#ifdef __MMX__
// It's ok to use MMX instructions based on the -march option (or
// the default for x86_64 or for Intel Mac).
#define MOZILLA_PRESUME_MMX 1
#endif
#ifdef __SSE__
// It's ok to use SSE instructions based on the -march option (or
// the default for x86_64 or for Intel Mac).
#define MOZILLA_PRESUME_SSE 1
#endif
#ifdef __SSE2__
// It's ok to use SSE2 instructions based on the -march option (or
// the default for x86_64 or for Intel Mac).
#define MOZILLA_PRESUME_SSE2 1
#endif
#ifdef __SSE3__
// It's ok to use SSE3 instructions based on the -march option (or the
// default for Intel Mac).
#define MOZILLA_PRESUME_SSE3 1
#endif
#ifdef __SSSE3__
// It's ok to use SSSE3 instructions based on the -march option.
#define MOZILLA_PRESUME_SSSE3 1
#endif
#ifdef __SSE4A__
// It's ok to use SSE4A instructions based on the -march option.
#define MOZILLA_PRESUME_SSE4A 1
#endif
#ifdef __SSE4_1__
// It's ok to use SSE4.1 instructions based on the -march option.
#define MOZILLA_PRESUME_SSE4_1 1
#endif
#ifdef __SSE4_2__
// It's ok to use SSE4.2 instructions based on the -march option.
#define MOZILLA_PRESUME_SSE4_2 1
#endif
#ifdef HAVE_CPUID_H
#define MOZILLA_SSE_HAVE_CPUID_DETECTION
#endif
#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64))
#define MOZILLA_SSE_HAVE_CPUID_DETECTION
#if defined(_M_IX86_FP)
#if _M_IX86_FP >= 1
// It's ok to use SSE instructions based on the /arch option
#define MOZILLA_PRESUME_SSE
#endif
#if _M_IX86_FP >= 2
// It's ok to use SSE2 instructions based on the /arch option
#define MOZILLA_PRESUME_SSE2
#endif
#elif defined(_M_AMD64)
// MSVC for AMD64 doesn't support MMX, so don't presume it here.
// SSE is always available on AMD64.
#define MOZILLA_PRESUME_SSE
// SSE2 is always available on AMD64.
#define MOZILLA_PRESUME_SSE2
#endif
#elif defined(__SUNPRO_CC) && (defined(__i386) || defined(__x86_64__))
// Sun Studio on x86 or amd64
#define MOZILLA_SSE_HAVE_CPUID_DETECTION
#if defined(__x86_64__)
// MMX is always available on AMD64.
#define MOZILLA_PRESUME_MMX
// SSE is always available on AMD64.
#define MOZILLA_PRESUME_SSE
// SSE2 is always available on AMD64.
#define MOZILLA_PRESUME_SSE2
#endif
#endif
namespace mozilla {
namespace sse_private {
#if defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#if !defined(MOZILLA_PRESUME_MMX)
extern bool MFBT_DATA mmx_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSE)
extern bool MFBT_DATA sse_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSE2)
extern bool MFBT_DATA sse2_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSE3)
extern bool MFBT_DATA sse3_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSSE3)
extern bool MFBT_DATA ssse3_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSE4A)
extern bool MFBT_DATA sse4a_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSE4_1)
extern bool MFBT_DATA sse4_1_enabled;
#endif
#if !defined(MOZILLA_PRESUME_SSE4_2)
extern bool MFBT_DATA sse4_2_enabled;
#endif
#endif
} // namespace sse_private
#if defined(MOZILLA_PRESUME_MMX)
#define MOZILLA_MAY_SUPPORT_MMX 1
inline bool supports_mmx() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#if !(defined(_MSC_VER) && defined(_M_AMD64))
// Define MOZILLA_MAY_SUPPORT_MMX only if we're not on MSVC for
// AMD64, since that compiler doesn't support MMX.
#define MOZILLA_MAY_SUPPORT_MMX 1
#endif
inline bool supports_mmx() { return sse_private::mmx_enabled; }
#else
inline bool supports_mmx() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSE)
#define MOZILLA_MAY_SUPPORT_SSE 1
inline bool supports_sse() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSE 1
inline bool supports_sse() { return sse_private::sse_enabled; }
#else
inline bool supports_sse() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSE2)
#define MOZILLA_MAY_SUPPORT_SSE2 1
inline bool supports_sse2() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSE2 1
inline bool supports_sse2() { return sse_private::sse2_enabled; }
#else
inline bool supports_sse2() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSE3)
#define MOZILLA_MAY_SUPPORT_SSE3 1
inline bool supports_sse3() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSE3 1
inline bool supports_sse3() { return sse_private::sse3_enabled; }
#else
inline bool supports_sse3() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSSE3)
#define MOZILLA_MAY_SUPPORT_SSSE3 1
inline bool supports_ssse3() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSSE3 1
inline bool supports_ssse3() { return sse_private::ssse3_enabled; }
#else
inline bool supports_ssse3() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSE4A)
#define MOZILLA_MAY_SUPPORT_SSE4A 1
inline bool supports_sse4a() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSE4A 1
inline bool supports_sse4a() { return sse_private::sse4a_enabled; }
#else
inline bool supports_sse4a() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSE4_1)
#define MOZILLA_MAY_SUPPORT_SSE4_1 1
inline bool supports_sse4_1() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSE4_1 1
inline bool supports_sse4_1() { return sse_private::sse4_1_enabled; }
#else
inline bool supports_sse4_1() { return false; }
#endif
#if defined(MOZILLA_PRESUME_SSE4_2)
#define MOZILLA_MAY_SUPPORT_SSE4_2 1
inline bool supports_sse4_2() { return true; }
#elif defined(MOZILLA_SSE_HAVE_CPUID_DETECTION)
#define MOZILLA_MAY_SUPPORT_SSE4_2 1
inline bool supports_sse4_2() { return sse_private::sse4_2_enabled; }
#else
inline bool supports_sse4_2() { return false; }
#endif
} // namespace mozilla
#endif /* !defined(mozilla_SSE_h_) */
