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Refactor CPUID

This commit is contained in:
Michał Janiszewski 2017-12-06 11:04:55 +01:00 committed by Michał Janiszewski
parent 25c54165e8
commit 7116d88e98
1 changed files with 29 additions and 16 deletions
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45
src/openrct2/util/util.c
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@ -179,39 +179,52 @@ sint32 bitscanforward(sint32 source)
#if defined(__GNUC__) && (defined(__x86_64__) || defined(__i386__))
#include <cpuid.h>
#define OpenRCT2_POPCNT_GNUC
#define OpenRCT2_CPUID_GNUC_X86
#define OPENRCT2_X86
#elif defined(_MSC_VER) && (_MSC_VER >= 1500) && (defined(_M_X64) || defined(_M_IX86)) // VS2008
#include <nmmintrin.h>
#define OpenRCT2_POPCNT_MSVC
#define OpenRCT2_CPUID_MSVC_X86
#define OPENRCT2_X86
#endif
#ifdef OPENRCT2_X86
static bool cpuid_x86(uint32 * cpuid_outdata, sint32 eax)
{
#if defined(OpenRCT2_CPUID_GNUC_X86)
int ret = __get_cpuid(eax, &cpuid_outdata[0], &cpuid_outdata[1], &cpuid_outdata[2], &cpuid_outdata[3]);
return ret == 1;
#elif defined(OpenRCT2_CPUID_MSVC_X86)
__cpuid(cpuid_outdata, eax);
return true;
#else
return false;
#endif
}
#endif // OPENRCT2_X86
static bool bitcount_popcnt_available()
{
#ifdef OPENRCT2_X86
// POPCNT support is declared as the 23rd bit of ECX with CPUID(EAX = 1).
#if defined(OpenRCT2_POPCNT_GNUC)
// we could use __builtin_cpu_supports, but it requires runtime support from
// the compiler's library, which clang doesn't have yet.
uint32 eax, ebx, ecx = 0, edx; // avoid "maybe uninitialized"
__get_cpuid(1, &eax, &ebx, &ecx, &edx);
return (ecx & (1 << 23));
#elif defined(OpenRCT2_POPCNT_MSVC)
sint32 regs[4];
__cpuid(regs, 1);
uint32 regs[4] = {};
if (cpuid_x86(regs, 1))
{
return (regs[2] & (1 << 23));
#else
return false;
#endif
}
#endif
return false;
}
static sint32 bitcount_popcnt(uint32 source)
{
#if defined(OpenRCT2_POPCNT_GNUC)
// Use CPUID defines to figure out calling style
#if defined(OpenRCT2_CPUID_GNUC_X86)
// use asm directly in order to actually emit the instruction : using
// __builtin_popcount results in an extra call to a library function.
sint32 rv;
asm volatile ("popcnt %1,%0" : "=r"(rv) : "rm"(source) : "cc");
return rv;
#elif defined(OpenRCT2_POPCNT_MSVC)
#elif defined(OpenRCT2_CPUID_MSVC_X86)
return _mm_popcnt_u32(source);
#else
openrct2_assert(false, "bitcount_popcnt() called, without support compiled in");