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fp: Move FPToFixed to its own file

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This commit is contained in:
MerryMage 2018-07-16 12:51:36 +01:00
parent 295deb4035
commit 797e18cd97
4 changed files with 25 additions and 15 deletions
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101
src/common/fp/op.cpp
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@ -1,101 +0,0 @@
/* This file is part of the dynarmic project.
* Copyright (c) 2018 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 "common/assert.h"
#include "common/bit_util.h"
#include "common/common_types.h"
#include "common/safe_ops.h"
#include "common/fp/fpsr.h"
#include "common/fp/mantissa_util.h"
#include "common/fp/op.h"
#include "common/fp/process_exception.h"
#include "common/fp/rounding_mode.h"
#include "common/fp/unpacked.h"
#include "frontend/A64/FPCR.h"
namespace Dynarmic::FP {
template<typename FPT>
u64 FPToFixed(size_t ibits, FPT op, size_t fbits, bool unsigned_, FPCR fpcr, RoundingMode rounding, FPSR& fpsr) {
ASSERT(rounding != RoundingMode::ToOdd);
ASSERT(ibits <= 64);
ASSERT(fbits <= ibits);
auto [type, sign, value] = FPUnpack<FPT>(op, fpcr, fpsr);
if (type == FPType::SNaN || type == FPType::QNaN) {
FPProcessException(FPExc::InvalidOp, fpcr, fpsr);
}
// Handle zero
if (value.mantissa == 0) {
return 0;
}
if (sign && unsigned_) {
FPProcessException(FPExc::InvalidOp, fpcr, fpsr);
return 0;
}
// value *= 2.0^fbits
value.exponent += static_cast<int>(fbits);
u64 int_result = sign ? Safe::Negate<u64>(value.mantissa) : static_cast<u64>(value.mantissa);
const ResidualError error = ResidualErrorOnRightShift(int_result, -value.exponent);
int_result = Safe::ArithmeticShiftLeft(int_result, value.exponent);
bool round_up = false;
switch (rounding) {
case RoundingMode::ToNearest_TieEven:
round_up = error > ResidualError::Half || (error == ResidualError::Half && Common::Bit<0>(int_result));
break;
case RoundingMode::TowardsPlusInfinity:
round_up = error != ResidualError::Zero;
break;
case RoundingMode::TowardsMinusInfinity:
round_up = false;
break;
case RoundingMode::TowardsZero:
round_up = error != ResidualError::Zero && Common::MostSignificantBit(int_result);
break;
case RoundingMode::ToNearest_TieAwayFromZero:
round_up = error > ResidualError::Half || (error == ResidualError::Half && !Common::MostSignificantBit(int_result));
break;
case RoundingMode::ToOdd:
UNREACHABLE();
}
if (round_up) {
int_result++;
}
// Detect Overflow
const int min_exponent_for_overflow = static_cast<int>(ibits) - static_cast<int>(Common::HighestSetBit(value.mantissa + (round_up ? 1 : 0))) - (unsigned_ ? 0 : 1);
if (value.exponent >= min_exponent_for_overflow) {
// Positive overflow
if (unsigned_ || !sign) {
FPProcessException(FPExc::InvalidOp, fpcr, fpsr);
return Common::Ones<u64>(ibits - (unsigned_ ? 0 : 1));
}
// Negative overflow
const u64 min_value = Safe::Negate<u64>(static_cast<u64>(1) << (ibits - 1));
if (!(value.exponent == min_exponent_for_overflow && int_result == min_value)) {
FPProcessException(FPExc::InvalidOp, fpcr, fpsr);
return static_cast<u64>(1) << (ibits - 1);
}
}
if (error != ResidualError::Zero) {
FPProcessException(FPExc::Inexact, fpcr, fpsr);
}
return int_result & Common::Ones<u64>(ibits);
}
template u64 FPToFixed<u32>(size_t ibits, u32 op, size_t fbits, bool unsigned_, FPCR fpcr, RoundingMode rounding, FPSR& fpsr);
template u64 FPToFixed<u64>(size_t ibits, u64 op, size_t fbits, bool unsigned_, FPCR fpcr, RoundingMode rounding, FPSR& fpsr);
} // namespace Dynarmic::FP