Line data    Source code

       1             : /* Copyright (C) 2022 Wildfire Games.
       2             :  *
       3             :  * Permission is hereby granted, free of charge, to any person obtaining
       4             :  * a copy of this software and associated documentation files (the
       5             :  * "Software"), to deal in the Software without restriction, including
       6             :  * without limitation the rights to use, copy, modify, merge, publish,
       7             :  * distribute, sublicense, and/or sell copies of the Software, and to
       8             :  * permit persons to whom the Software is furnished to do so, subject to
       9             :  * the following conditions:
      10             :  *
      11             :  * The above copyright notice and this permission notice shall be included
      12             :  * in all copies or substantial portions of the Software.
      13             :  *
      14             :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
      15             :  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
      16             :  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
      17             :  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
      18             :  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
      19             :  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
      20             :  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      21             :  */
      22             : 
      23             : /*
      24             :  * CPU and memory detection.
      25             :  */
      26             : 
      27             : #ifndef INCLUDED_CPU
      28             : #define INCLUDED_CPU
      29             : 
      30             : #include "lib/sysdep/compiler.h"
      31             : 
      32             : 
      33             : namespace ERR
      34             : {
      35             :     const Status CPU_FEATURE_MISSING     = -130000;
      36             :     const Status CPU_UNKNOWN_OPCODE      = -130001;
      37             :     const Status CPU_UNKNOWN_VENDOR      = -130002;
      38             : 
      39             : }
      40             : 
      41             : 
      42             : //-----------------------------------------------------------------------------
      43             : // CPU detection
      44             : 
      45             : /**
      46             :  * @return string identifying the CPU (usually a cleaned-up version of the
      47             :  * brand string)
      48             :  **/
      49             : const char* cpu_IdentifierString();
      50             : 
      51             : 
      52             : //-----------------------------------------------------------------------------
      53             : // lock-free support routines
      54             : 
      55             : /**
      56             :  * add a signed value to a variable without the possibility of interference
      57             :  * from other threads/CPUs.
      58             :  *
      59             :  * @return the previous value.
      60             :  **/
      61             : intptr_t cpu_AtomicAdd(volatile intptr_t* location, intptr_t increment);
      62             : 
      63             : /**
      64             :  * atomic "compare and swap".
      65             :  *
      66             :  * @param location address of the word to compare and possibly overwrite
      67             :  * @param expected its expected value
      68             :  * @param newValue the value with which to replace it
      69             :  * @return false if the target word doesn't match the expected value,
      70             :  * otherwise true (also overwriting the contents of location)
      71             :  **/
      72             : bool cpu_CAS(volatile intptr_t* location, intptr_t expected, intptr_t newValue);
      73             : bool cpu_CAS64(volatile i64* location, i64 expected, i64 newValue);
      74             : 
      75             : /**
      76             :  * specialization of cpu_CAS for pointer types. this avoids error-prone
      77             :  * casting in user code.
      78             :  **/
      79             : template<typename T>
      80             : inline bool cpu_CAS(volatile T* location, T expected, T new_value)
      81             : {
      82             :     return cpu_CAS((volatile intptr_t*)location, (intptr_t)expected, (intptr_t)new_value);
      83             : }
      84             : 
      85             : 
      86             : void cpu_Test();
      87             : 
      88             : /**
      89             :  * pause in spin-wait loops, as a performance optimisation.
      90             :  **/
      91           0 : inline void cpu_Pause()
      92             : {
      93             : #if MSC_VERSION && ARCH_X86_X64
      94             :     _mm_pause();
      95             : #elif GCC_VERSION && ARCH_X86_X64
      96           0 :     __asm__ __volatile__( "rep; nop" : : : "memory" );
      97             : #endif
      98           0 : }
      99             : 
     100             : #endif  // #ifndef INCLUDED_CPU