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// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <cfenv>
#include "Common/CPUDetect.h"
#include "Common/CommonTypes.h"
#include "Common/FPURoundMode.h"
#include "Common/Intrinsics.h"
namespace FPURoundMode
{
// Get the default SSE states here.
static u32 saved_sse_state = _mm_getcsr();
static const u32 default_sse_state = _mm_getcsr();
void SetRoundMode(int mode)
{
// Convert PowerPC to native rounding mode.
static const int rounding_mode_lut[] = {FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD, FE_DOWNWARD};
fesetround(rounding_mode_lut[mode]);
}
void SetPrecisionMode(PrecisionMode /* mode */)
{
// x64 doesn't need this - fpu is done with SSE
}
void SetSIMDMode(int rounding_mode, bool non_ieee_mode)
{
// OR-mask for disabling FPU exceptions (bits 7-12 in the MXCSR register)
const u32 EXCEPTION_MASK = 0x1F80;
// Flush-To-Zero (non-IEEE mode: denormal outputs are set to +/- 0)
const u32 FTZ = 0x8000;
// lookup table for FPSCR.RN-to-MXCSR.RC translation
static const u32 simd_rounding_table[] = {
(0 << 13) | EXCEPTION_MASK, // nearest
(3 << 13) | EXCEPTION_MASK, // zero
(2 << 13) | EXCEPTION_MASK, // +inf
(1 << 13) | EXCEPTION_MASK, // -inf
};
u32 csr = simd_rounding_table[rounding_mode];
if (non_ieee_mode)
{
csr |= FTZ;
}
_mm_setcsr(csr);
}
void SaveSIMDState()
{
saved_sse_state = _mm_getcsr();
}
void LoadSIMDState()
{
_mm_setcsr(saved_sse_state);
}
void LoadDefaultSIMDState()
{
_mm_setcsr(default_sse_state);
}
} // namespace FPURoundMode
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