53 lines
1.9 KiB
C++
53 lines
1.9 KiB
C++
/* 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/. */
|
|
|
|
#ifndef mozilla_htmlaccel_htmlaccelEnabled_h
|
|
#define mozilla_htmlaccel_htmlaccelEnabled_h
|
|
|
|
#include "mozilla/Assertions.h"
|
|
#if defined(__x86_64__)
|
|
# include "mozilla/SSE.h"
|
|
#endif
|
|
|
|
namespace mozilla::htmlaccel {
|
|
|
|
// MOZ_MAY_HAVE_HTMLACCEL gets defined iff `htmlaccelEnabled()` may return
|
|
// `true`. The purpose is this define is to accommodate builds that don't
|
|
// link `htmlaccelNotInline.cpp` and have even the most basic constant
|
|
// propagation turned off so that `htmlaccelEnabled()` statically returning
|
|
// false isn't enough to remove calls to functions whose definitions are
|
|
// missing.
|
|
|
|
/// This function is appropriate to call when the SIMD path is compiled
|
|
/// with `HTML_ACCEL_FLAGS`.
|
|
///
|
|
/// Keep this in sync with `HTML_ACCEL_FLAGS` in `toolchain.configure`.
|
|
inline bool htmlaccelEnabled() {
|
|
#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ < 12
|
|
// __GNUC__ is stuck at 4 in clang, so we need to check __clang__ above.
|
|
// GCC 12 or newer is required for __builtin_shuffle.
|
|
return false;
|
|
#elif defined(__aarch64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
|
|
# define MOZ_MAY_HAVE_HTMLACCEL 1
|
|
return true;
|
|
#elif defined(__x86_64__)
|
|
# define MOZ_MAY_HAVE_HTMLACCEL 1
|
|
bool ret = mozilla::supports_bmi();
|
|
if (ret) {
|
|
// As a micro optimization for the innerHTML getter, don't bother
|
|
// calling `supports_avx` in release builds, since the implementation
|
|
// of SSE.h supports_bmi implies supports_avx anyway.
|
|
MOZ_ASSERT(mozilla::supports_avx(),
|
|
"supports_bmi is supposed to imply supports_avx");
|
|
}
|
|
return ret;
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
} // namespace mozilla::htmlaccel
|
|
|
|
#endif // mozilla_htmlaccel_htmlaccelEnabled_h
|