1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
// Copyright 2013 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include "Common/FPURoundMode.h"
#include <cfenv>
#include "Common/CPUDetect.h"
#include "Common/CommonTypes.h"
#include "Common/Intrinsics.h"
namespace Common::FPU
{
// Get the default SSE states here.
static u32 saved_sse_state = _mm_getcsr();
static const u32 default_sse_state = _mm_getcsr();
void SetSIMDMode(RoundMode 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 Common::FPU
|
