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forked from 0ad/0ad
0ad/source/lib/sysdep/cpu.h
janwas 98770fa4cc # fix race conditions in ModuleInit and related cleanup.
CAS: uintptr_t->intptr_t to allow use of both cpu_CAS and cpu_AtomicAdd
topology: remove non-thread safe caching, expose ApicIds, use ModuleInit
x86_x64: use ModuleInit instead of unsafe static flags; zero-init regs
instead of just setting ecx
ModuleInitState now holds the LibError returned by the init callback (so
that the second init doesn't appear to succeed despite the first
failing)
wnuma: cleanup, add ACPI SLIT relative distance detection

This was SVN commit r7741.
2010-07-12 12:57:58 +00:00

128 lines
3.9 KiB
C++

/* Copyright (c) 2010 Wildfire Games
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* CPU and memory detection.
*/
#ifndef INCLUDED_CPU
#define INCLUDED_CPU
#include "lib/sysdep/compiler.h"
namespace ERR
{
const LibError CPU_FEATURE_MISSING = -130000;
const LibError CPU_UNKNOWN_OPCODE = -130001;
const LibError CPU_UNKNOWN_VENDOR = -130002;
}
//-----------------------------------------------------------------------------
// CPU detection
/**
* @return string identifying the CPU (usually a cleaned-up version of the
* brand string)
**/
LIB_API const char* cpu_IdentifierString();
//-----------------------------------------------------------------------------
// lock-free support routines
/**
* prevent the CPU from reordering previous loads or stores past the barrier,
* thus ensuring they retire before any subsequent memory operations.
* this also prevents compiler reordering.
**/
#if MSC_VERSION
# include <intrin.h>
# if !ICC_VERSION
# pragma intrinsic(_ReadWriteBarrier)
# endif
# define cpu_MemoryBarrier() _ReadWriteBarrier()
#elif GCC_VERSION
# define cpu_MemoryBarrier() asm volatile("" : : : "memory")
#else
# define cpu_MemoryBarrier()
#endif
/**
* atomic "compare and swap".
*
* @param location address of the word to compare and possibly overwrite
* @param expected its expected value
* @param newValue the value with which to replace it
* @return false if the target word doesn't match the expected value,
* otherwise true (also overwriting the contents of location)
**/
LIB_API bool cpu_CAS(volatile intptr_t* location, intptr_t expected, intptr_t newValue);
/**
* specialization of cpu_CAS for pointer types. this avoids error-prone
* casting in user code.
**/
template<typename T>
bool cpu_CAS(volatile T* location, T expected, T new_value)
{
return cpu_CAS((volatile intptr_t*)location, (intptr_t)expected, (intptr_t)new_value);
}
/**
* add a signed value to a variable without the possibility of interference
* from other threads/CPUs.
**/
LIB_API void cpu_AtomicAdd(volatile intptr_t* location, intptr_t increment);
/**
* enforce strict instruction ordering in the CPU pipeline.
**/
LIB_API void cpu_Serialize();
//-----------------------------------------------------------------------------
// misc
/**
* drop-in replacement for POSIX memcpy().
**/
LIB_API void* cpu_memcpy(void* RESTRICT dst, const void* RESTRICT src, size_t size);
/**
* set the FPU control word to "desirable" values (see implementation)
**/
LIB_API void cpu_ConfigureFloatingPoint();
// convert float to int much faster than _ftol2, which would normally be
// used by (int) casts.
// VC8 and GCC with -ffast-math now manage to generate SSE instructions,
// so our implementation is no longer needed.
#define cpu_i32FromFloat(f) ((i32)(f))
#define cpu_i32FromDouble(d) ((i32)(d))
#define cpu_i64FromDouble(d) ((i64)(d))
#endif // #ifndef INCLUDED_CPU