reactos/include/crt/mingw32/intrin.h

   1 /*
   2         Compatibility <intrin.h> header for GCC -- GCC equivalents of intrinsic
   3         Microsoft Visual C++ functions. Originally developed for the ReactOS
   4         (<http://www.reactos.org/>) and TinyKrnl (<http://www.tinykrnl.org/>)
   5         projects.
   6
   7         Copyright (c) 2006 KJK::Hyperion <hackbunny@reactos.com>
   8
   9         Permission is hereby granted, free of charge, to any person obtaining a
  10         copy of this software and associated documentation files (the "Software"),
  11         to deal in the Software without restriction, including without limitation
  12         the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13         and/or sell copies of the Software, and to permit persons to whom the
  14         Software is furnished to do so, subject to the following conditions:
  15
  16         The above copyright notice and this permission notice shall be included in
  17         all copies or substantial portions of the Software.
  18
  19         THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20         IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21         FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22         AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23         LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24         FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25         DEALINGS IN THE SOFTWARE.
  26 */
  27
  28 #ifndef KJK_INTRIN_H_
  29 #define KJK_INTRIN_H_
  30
  31 #ifndef RC_INVOKED
  32
  33 #ifndef __GNUC__
  34 #error Unsupported compiler
  35 #endif
  36
  37 /*
  38         FIXME: review all "memory" clobbers, add/remove to match Visual C++
  39         behavior: some "obvious" memory barriers are not present in the Visual C++
  40         implementation - e.g. __stosX; on the other hand, some memory barriers that
  41         *are* present could have been missed
  42 */
  43
  44 /*
  45         NOTE: this is a *compatibility* header. Some functions may look wrong at
  46         first, but they're only "as wrong" as they would be on Visual C++. Our
  47         priority is compatibility
  48
  49         NOTE: unlike most people who write inline asm for GCC, I didn't pull the
  50         constraints and the uses of __volatile__ out of my... hat. Do not touch
  51         them. I hate cargo cult programming
  52
  53         NOTE: be very careful with declaring "memory" clobbers. Some "obvious"
  54         barriers aren't there in Visual C++ (e.g. __stosX)
  55
  56         NOTE: review all intrinsics with a return value, add/remove __volatile__
  57         where necessary. If an intrinsic whose value is ignored generates a no-op
  58         under Visual C++, __volatile__ must be omitted; if it always generates code
  59         (for example, if it has side effects), __volatile__ must be specified. GCC
  60         will only optimize out non-volatile asm blocks with outputs, so input-only
  61         blocks are safe. Oddities such as the non-volatile 'rdmsr' are intentional
  62         and follow Visual C++ behavior
  63
  64         NOTE: on GCC 4.1.0, please use the __sync_* built-ins for barriers and
  65         atomic operations. Test the version like this:
  66
  67         #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) > 40100
  68                 ...
  69
  70         Pay attention to the type of barrier. Make it match with what Visual C++
  71         would use in the same case
  72 */
  73
  74 #if defined(__i386__)
  75 #include "intrin_x86.h"
  76 #elif defined(_PPC_)
  77 #include "intrin_ppc.h"
  78 #elif defined(_MIPS_)
  79 #include "intrin_mips.h"
  80 #elif defined(_M_ARM)
  81 #include "intrin_arm.h"
  82 #elif defined(__x86_64__)
  83 /* TODO: the x64 architecture shares most of the i386 intrinsics. It should be easy to support */
  84 #include "intrin_x86.h"
  85 #else
  86 #error Unsupported architecture
  87 #endif
  88
  89
  90 /*** Miscellaneous ***/
  91 /* BUGBUG: only good for use in macros. Cannot be taken the address of */
  92 #define __noop(...) ((void)0)
  93
  94 /* TODO: __assume. GCC only supports the weaker __builtin_expect */
  95
  96 #endif
  97
  98 #endif
  99
 100 /* EOF */