Files
kernels/sim/common/util.cpp
2021-10-09 10:20:42 -04:00

92 lines
2.6 KiB
C++

#include "util.h"
#include <iostream>
#include <stdexcept>
#include <math.h>
#include <climits>
#include <string.h>
#include <bitset>
#include <fcntl.h>
using namespace vortex;
// Apply integer sign extension
uint32_t vortex::signExt(uint32_t w, uint32_t bit, uint32_t mask) {
if (w >> (bit - 1))
w |= ~mask;
return w;
}
// Convert a floating point number to IEEE-754 32-bit representation,
// so that it could be stored in a 32-bit integer register file
// Reference: https://www.wikihow.com/Convert-a-Number-from-Decimal-to-IEEE-754-Floating-Point-Representation
// https://www.technical-recipes.com/2012/converting-between-binary-and-decimal-representations-of-ieee-754-floating-point-numbers-in-c/
uint32_t vortex::floatToBin(float in_value) {
union {
float input; // assumes sizeof(float) == sizeof(int)
int output;
} data;
data.input = in_value;
std::bitset<sizeof(float) * CHAR_BIT> bits(data.output);
std::string mystring = bits.to_string<char, std::char_traits<char>, std::allocator<char>>();
// Convert binary to uint32_t
uint32_t result = stoul(mystring, nullptr, 2);
return result;
}
// https://en.wikipedia.org/wiki/Single-precision_floating-point_format
// check floating-point number in binary format is NaN
uint8_t vortex::fpBinIsNan(uint32_t din) {
bool fsign = din & 0x80000000;
uint32_t expo = (din>>23) & 0x000000FF;
uint32_t fraction = din & 0x007FFFFF;
uint32_t bit_22 = din & 0x00400000;
if ((expo==0xFF) && (fraction!=0)) {
// if (!fsign && (fraction == 0x00400000))
if (!fsign && (bit_22))
return 1; // quiet NaN, return 1
else
return 2; // signaling NaN, return 2
}
return 0;
}
// check floating-point number in binary format is zero
uint8_t vortex::fpBinIsZero(uint32_t din) {
bool fsign = din & 0x80000000;
uint32_t expo = (din>>23) & 0x000000FF;
uint32_t fraction = din & 0x007FFFFF;
if ((expo==0) && (fraction==0)) {
if (fsign)
return 1; // negative 0
else
return 2; // positive 0
}
return 0; // not zero
}
// check floating-point number in binary format is infinity
uint8_t vortex::fpBinIsInf(uint32_t din) {
bool fsign = din & 0x80000000;
uint32_t expo = (din>>23) & 0x000000FF;
uint32_t fraction = din & 0x007FFFFF;
if ((expo==0xFF) && (fraction==0)) {
if (fsign)
return 1; // negative infinity
else
return 2; // positive infinity
}
return 0; // not infinity
}
// return file extension
const char* vortex::fileExtension(const char* filepath) {
const char *ext = strrchr(filepath, '.');
if (ext == NULL || ext == filepath)
return "";
return ext + 1;
}