singrdk/base/Kernel/Native/arm/Crt/fpraise.cpp

148 lines
5.2 KiB
C++

//////////////////////////////////////////////////////////////////////////////////////////////////
//
// Microsoft Research Singularity
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// This file contains ARM-specific FP code.
//
//
// FP_CODE
//
// Enumerated type containing all base FP operations that can raise exceptions.
// This must agree with the defines in fpe.asm.
//
typedef enum
{
_FpAddD, // Add Double
_FpAddS, // Add Single
_FpSubD, // Subtract Double
_FpSubS, // Subtract Single
_FpCmpD, // Compare Double
_FpCmpS, // Compare Single
_FpDivD, // Divide Double
_FpDivS, // Divide Single
_FpDToI, // Convert Double To int
_FpDToI64, // Convert Double To __int64
_FpDToS, // Convert Double To Single
_FpDToU, // Convert Double To unsigned int
_FpDToU64, // Convert Double To unsigned __int64
_FpIToS, // Convert int To Single
_FpMulD, // Multiply Double
_FpMulS, // Multiply Single
_FpSToD, // Convert Single To Double
_FpSToI, // Convert Single To int
_FpSToI64, // Convert Single To __int64
_FpSToU, // Convert Single To unsigned int
_FpSToU64, // Convert Single To unsigned __int64
_FpUToS, // Convert unsigned int To Single
_FpI64ToD, // Convert __int64 To Double
_FpI64ToS, // Convert __int64 To Single
_FpU64ToD, // Convert unsigned __int64 To Double
_FpU64ToS, // Convert unsigned __int64 To Single
_FpRndD // Round to double integer
} FP_CODE;
//
// FP_VALUE
//
// A floating-point emulation routine supplies an FP_VALUE for each operand and
// the result. The proper alias in the union is determined by the corresponding
// FP_OP. This structure must be exactly 8 bytes big (corresponding to
// sizeof(double)). Note that extended formats such as long double are not
// supported.
typedef union {
float Fp32Value; // IEEE 32-bit floating-point value
double Fp64Value; // IEEE 64-bit floating-point value
int I32Value; // Signed 32-bit integer value
__int64 I64Value; // Signed 64-bit integer value
unsigned int U32Value; // Unsigned 32-bit integer value
unsigned __int64 U64Value; // Unsigned 64-bit integer value
int CompareValue; // One of _FPIEEE_COMPARE_RESULT enums
} FP_VALUE;
//
// FPExInfo
//
// This must match the defines for exception information in fpe.s.
//
typedef union
{
unsigned int Raw;
struct
{
unsigned int CauseInvalid : 1; // Bit 0
unsigned int CauseZeroDivide : 1; // Bit 1
unsigned int CauseOverflow : 1; // Bit 2
unsigned int CauseUnderflow : 1; // Bit 3
unsigned int CauseInexact : 1; // Bit 4
unsigned int Reserved2 : 15; // Bits 19:5
unsigned int Operation : 5; // Bits 24:20
unsigned int Reserved1 : 7; // Bits 31:25
} Field;
} FPExInfo;
//++
//
//Routine Description:
//
// This function accepts basic IEEE floating-point exception information from
// a software emulation routine that detected the exception. All of the
// exception information is packaged into a standard _FPIEEE_RECORD structure
// and passed to RaiseException. On return from RaiseException, the structure
// is unpacked, causing anything that the user changed to be reflected in the
// floating-point status. The calling parameters have been selected and
// arranged for the convenience of the assembly language coded emulation
// routines.
//
// A user typically calls _fpieee_flt, the standard SEH exception filter for
// IEEE floating-point exceptions, to gain access to the _FPIEEE_RECORD
// structure. On a system with hardware floating-point instructions, the
// _fpieee_flt exception filter decodes the results of the floating-point trap
// (often decoding instruction opcodes and other state left by the kernel) and
// builds the _FPIEEE_RECORD structure itself. But since the SH-3 uses
// software floating-point emulation, we use the same reporting mechanism that
// the math library uses. In this case, _fpieee_flt detects that an
// _FPIEEE_RECORD has already been created for the exception and simply passes
// it through.
//
//Arguments:
//
// ExInfo - Supplies the exception information regarding operation and cause.
//
// Operand1 - Supplies the original first operand.
//
// Operand2 - Supplies the original second operand.
//
// Result - Supplies the default result if the user simply continues.
//
//Return Value:
//
// The result, possibly modified by the user's exception handler, after return
// from RaiseException. The software emulation routine substitutes this value
// for the result it returns.
//
//--
extern "C"
FP_VALUE
FPE_Raise (
FPExInfo ExInfo,
FP_VALUE Operand1,
FP_VALUE Operand2,
FP_VALUE Result
)
{
__debugbreak();
return Result;
}