dynarmic/src/backend_x64/jitstate.cpp

114 lines
3.6 KiB
C++
Raw Normal View History

/* This file is part of the dynarmic project.
* Copyright (c) 2016 MerryMage
* This software may be used and distributed according to the terms of the GNU
* General Public License version 2 or any later version.
*/
#include "backend_x64/jitstate.h"
#include "common/assert.h"
#include "common/bit_util.h"
#include "common/common_types.h"
namespace Dynarmic {
namespace BackendX64 {
/**
* Comparing MXCSR and FPSCR
* =========================
*
* SSE MXCSR exception flags
* -------------------------
* PE bit 5 Precision Flag
* UE bit 4 Underflow Flag
* OE bit 3 Overflow Flag
* ZE bit 2 Divide By Zero Flag
* DE bit 1 Denormal Flag
* IE bit 0 Invalid Operation Flag
*
* VFP FPSCR cumulative exception bits
* -----------------------------------
* IDC bit 7 Input Denormal cumulative exception bit
* IXC bit 4 Inexact cumulative exception bit
* UFC bit 3 Underflow cumulative exception bit
* OFC bit 2 Overflow cumulative exception bit
* DZC bit 1 Division by Zero cumulative exception bit
* IOC bit 0 Invalid Operation cumulative exception bit
*
* SSE MSCSR exception masks
* -------------------------
* PM bit 12 Precision Mask
* UM bit 11 Underflow Mask
* OM bit 10 Overflow Mask
* ZM bit 9 Divide By Zero Mask
* DM bit 8 Denormal Mask
* IM bit 7 Invalid Operation Mask
*
* VFP FPSCR exception trap enables
* --------------------------------
* IDE bit 15 Input Denormal exception trap enable
* IXE bit 12 Inexact exception trap enable
* UFE bit 11 Underflow exception trap enable
* OFE bit 10 Overflow exception trap enable
* DZE bit 9 Division by Zero exception trap enable
* IOE bit 8 Invalid Operation exception trap enable
*
* SSE MXCSR mode bits
* -------------------
* FZ bit 15 Flush To Zero
* DAZ bit 6 Denormals Are Zero
* RN bits 13-14 Round to {0 = Nearest, 1 = Negative, 2 = Positive, 3 = Zero}
*
* VFP FPSCR mode bits
* -------------------
* DN bit 25 Default NaN
* FZ bit 24 Flush to Zero
* RMode bits 22-23 Round to {0 = Nearest, 1 = Positive, 2 = Negative, 3 = Zero}
* Stride bits 20-21 Vector stride
* Len bits 16-18 Vector length
*/
// NZCV; QC (ASMID only), AHP; DN, FZ, RMode, Stride; SBZP; Len; trap enables; cumulative bits
constexpr u32 FPSCR_MASK = 0b1111'00'111111'0'111'10011111'00000000;
u32 JitState::Fpscr() const {
ASSERT((guest_FPSCR_flags & ~FPSCR_MASK) == 0);
u32 FPSCR = guest_FPSCR_flags;
FPSCR |= (guest_MXCSR & 0b0000000000001); // IOC = IE
FPSCR |= (guest_MXCSR & 0b0000000000010) << 6; // IDC = DE
FPSCR |= (guest_MXCSR & 0b0000000111100) >> 1; // IXC, UFC, OFC, DZC = PE, UE, OE, ZE
if (!Common::Bit<24>(FPSCR)) {
// ARM only sets IDC if FTZ == 1.
FPSCR &= ~(1 << 7);
FPSCR |= old_FPSCR & (1 << 7);
}
return FPSCR;
}
void JitState::SetFpscr(u32 FPSCR) {
old_FPSCR = FPSCR;
guest_FPSCR_flags = FPSCR & FPSCR_MASK;
guest_MXCSR = 0;
guest_MXCSR |= ( FPSCR ) & 0b0000000000001; // IE = IOC
guest_MXCSR |= ( FPSCR >> 6) & 0b0000000000010; // DE = IDC
guest_MXCSR |= ( FPSCR << 1) & 0b0000000111100; // PE, UE, OE, ZE = IXC, UFC, OFC, DZC
guest_MXCSR |= (~FPSCR >> 1) & 0b0000010000000; // IM = ~IOE
guest_MXCSR |= (~FPSCR >> 7) & 0b0000100000000; // DM = ~IDE
guest_MXCSR |= (~FPSCR ) & 0b1111000000000; // PM, UM, OM, ZM = ~IXE, ~UFE, ~OFE, ~DZE
if (Common::Bit<24>(FPSCR)) {
// VFP Flush to Zero
guest_MXCSR |= (1 << 15); // SSE Flush to Zero
guest_MXCSR |= (1 << 6); // SSE Denormals are Zero
}
}
} // namespace BackendX64
} // namespace Dynarmic