clang/lib/Headers/hresetintrin.h

   1 /*===---------------- hresetintrin.h - HRESET intrinsics -------------------===
   2  *
   3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4  * See https://llvm.org/LICENSE.txt for license information.
   5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6  *
   7  *===-----------------------------------------------------------------------===
   8  */
   9 #ifndef __X86GPRINTRIN_H
  10 #error "Never use <hresetintrin.h> directly; include <x86gprintrin.h> instead."
  11 #endif
  12
  13 #ifndef __HRESETINTRIN_H
  14 #define __HRESETINTRIN_H
  15
  16 #if __has_extension(gnu_asm)
  17
  18 /* Define the default attributes for the functions in this file. */
  19 #define __DEFAULT_FN_ATTRS \
  20   __attribute__((__always_inline__, __nodebug__, __target__("hreset")))
  21
  22 /// Provides a hint to the processor to selectively reset the prediction
  23 ///    history of the current logical processor specified by a 32-bit integer
  24 ///    value \a __eax.
  25 ///
  26 /// This intrinsic corresponds to the <c> HRESET </c> instruction.
  27 ///
  28 /// \code{.operation}
  29 ///    IF __eax == 0
  30 ///      // nop
  31 ///    ELSE
  32 ///      FOR i := 0 to 31
  33 ///        IF __eax[i]
  34 ///          ResetPredictionFeature(i)
  35 ///        FI
  36 ///      ENDFOR
  37 ///    FI
  38 /// \endcode
  39 static __inline void __DEFAULT_FN_ATTRS
  40 _hreset(int __eax)
  41 {
  42   __asm__ ("hreset $0" :: "a"(__eax));
  43 }
  44
  45 #undef __DEFAULT_FN_ATTRS
  46
  47 #endif /* __has_extension(gnu_asm) */
  48
  49 #endif /* __HRESETINTRIN_H */