dynarmic/src/backend/x64/a64_jitstate.cpp
2020-04-23 15:45:57 +01:00

110 lines
3.3 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2016 MerryMage
* SPDX-License-Identifier: 0BSD
*/
#include "backend/x64/a64_jitstate.h"
#include "common/bit_util.h"
#include "frontend/A64/location_descriptor.h"
namespace Dynarmic::Backend::X64 {
/**
* Comparing MXCSR and FPCR
* ========================
*
* 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
*
* A64 FPCR 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}
*
* A64 FPCR mode bits
* ------------------
* AHP bit 26 Alternative half-precision
* 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}
* FZ16 bit 19 Flush to Zero for half-precision
*/
constexpr u32 FPCR_MASK = 0x07C89F00;
u32 A64JitState::GetFpcr() const {
return fpcr;
}
void A64JitState::SetFpcr(u32 value) {
fpcr = value & FPCR_MASK;
guest_MXCSR &= 0x0000003D;
guest_MXCSR |= 0x00001f80; // Mask all exceptions
// RMode
const std::array<u32, 4> MXCSR_RMode {0x0, 0x4000, 0x2000, 0x6000};
guest_MXCSR |= MXCSR_RMode[(value >> 22) & 0x3];
if (Common::Bit<24>(value)) {
guest_MXCSR |= (1 << 15); // SSE Flush to Zero
guest_MXCSR |= (1 << 6); // SSE Denormals are Zero
}
}
/**
* Comparing MXCSR and FPSR
* ========================
*
* 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 // Appears to only be set when MXCSR.DAZ = 0
* IE bit 0 Invalid Operation Flag
*
* A64 FPSR cumulative exception bits
* ----------------------------------
* QC bit 27 Cumulative saturation bit
* IDC bit 7 Input Denormal cumulative exception bit // Only ever set when FPCR.FTZ = 1
* 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
*/
u32 A64JitState::GetFpsr() const {
u32 fpsr = 0;
fpsr |= (guest_MXCSR & 0b0000000000001); // IOC = IE
fpsr |= (guest_MXCSR & 0b0000000111100) >> 1; // IXC, UFC, OFC, DZC = PE, UE, OE, ZE
fpsr |= fpsr_exc;
fpsr |= (fpsr_qc == 0 ? 0 : 1) << 27;
return fpsr;
}
void A64JitState::SetFpsr(u32 value) {
guest_MXCSR &= ~0x0000003D;
fpsr_qc = (value >> 27) & 1;
fpsr_exc = value & 0x9F;
}
} // namespace Dynarmic::Backend::X64