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/* 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
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