Some rough floating point macros!

This commit is contained in:
Kat R. 2022-05-28 11:15:26 -05:00
parent 2ada975628
commit ef5fd0562f
4 changed files with 173 additions and 3 deletions

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@ -3,7 +3,7 @@
*
* This header is a part of the FENIX C Library and is free software.
* You can redistribute and/or modify it subject to the terms of the
* Clumsy Wolf Public License v4. For more details, see the file COPYING.
* Clumsy Wolf Public License v5. For more details, see the file COPYING.
*
* The FENIX C Library is distributed WITH NO WARRANTY WHATSOEVER. See
* The CWPL for more details.
@ -12,6 +12,8 @@
#ifndef _MATH_H
#define _MATH_H
#include <limits.h>
#if FLT_EVAL_METHOD == 1
typedef double float_t;
typedef double double_t;
@ -23,6 +25,44 @@ typedef float float_t;
typedef double double_t;
#endif
/* Both of these are basically lifted from musl. */
#define INFINITY (1e5000)
#define NAN (0.0f / 0.0f)
#define FP_INFINITE 1
#define FP_NAN 2
#define FP_NORMAL 3
#define FP_SUBNORMAL 4
#define FP_ZERO 0
int __fpclassifyd(double x);
int __fpclassifyf(float x);
int __fpclassifyl(long double x);
/* We're just gonna use the approach in the C standard here */
#define fpclassify(x) ((sizeof(x) == sizeof(float)) ? __fpclassifyf(x) : \
(sizeof(x) == sizeof(double)) ? __fpclassifyd(x) : \
__fpclassifyl(x))
#define isfinite(x) ((fpclassify(x) != FP_INFINITE) && (fpclassify(x) != FP_NAN))
#define isinf(x) (fpclassify(x) == FP_INFINITE)
#define isnan(x) (fpclassify(x) == FP_NAN)
#define isnormal(x) (fpclassify(x) == FP_NORMAL)
int __signbitd(double x);
int __signbitf(float x);
int __signbitl(long double x);
/*
In theory, I could just use (x < 0 || x == -0.0f), but would that work for
infinity and NaN? I feel like no. So fuck it. We'll just write some small
functions to pull the sign bit straight from the number.
-Kat
*/
#define signbit(x) ((sizeof(x) == sizeof(float)) ? __signbitf(x) : \
(sizeof(x) == sizeof(double)) ? __signbitd(x) : \
__signbitl(x))
#define M_E 2.718281828
#define M_PI 3.14159265
#define PI 3.14159265
@ -40,7 +80,10 @@ typedef double double_t;
#define MATH_ERRNO 1
#define MATH_ERREXCEPT 2
#define math_errhandling (int) (MATH_ERRNO | MATH_ERREXCEPT)
#define math_errhandling MATH_ERRNO
#define FP_ILOGB0 INT_MIN
#define FP_ILOGBNAN INT_MAX
double acos(double);
float acosf(float);

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@ -56,7 +56,7 @@ string/memset.o \
string/strcmp.o \
string/strcspn.o \
string/strlen.o \
string/strtok.o \
string/strtok.o
HOSTEDOBJS=\
$(ARCH_HOSTEDOBJS) \
@ -66,6 +66,8 @@ math/cosl.o \
math/fabs.o \
math/fabsf.o \
math/fabsl.o \
math/__fpclassify.o \
math/__signbit.o \
stdlib/abs.o \
stdlib/div.o \
stdlib/labs.o \

91
math/__fpclassify.c Normal file
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@ -0,0 +1,91 @@
#include <math.h>
int __fpclassifyd(double x) {
union fp {
double d;
long i;
} f;
f.d = x;
if((f.i & 0x7fffffffffffffff) == 0) {
return FP_ZERO;
}
if((f.i & 0x7ff0000000000000) == 0 && (f.i & 0xfffffffffffff != 0)) {
return FP_SUBNORMAL;
}
if((f.i & 0x7ff0000000000000) == 0x7ff0000000000000) {
if((f.i & 0xfffffffffffff) == 0) {
return FP_INFINITE;
}
else {
return FP_NAN;
}
}
return FP_NORMAL;
}
int __fpclassifyf(float x) {
union fp {
float f;
int i;
} f;
f.f = x;
if((f.i & 0x7fffffff) == 0) {
return FP_ZERO;
}
if((f.i & 0x7f800000) == 0 && (f.i & 0x7fffff != 0)) {
return FP_SUBNORMAL;
}
if((f.i & 0x7f800000) == 0x7f800000) {
if((f.i & 0x7fffff) == 0) {
return FP_INFINITE;
}
else {
return FP_NAN;
}
}
return FP_NORMAL;
}
/*
This is based off IEEE 754 binary128 (A.K.A quad-precision) FP numbers.
Apparently, C tends to actually use 80-bit extended precision, which would
mean this doesn't actually work. We'll worry about that later, though.
-Kat
*/
int __fpclassifyl(long double x) {
union fp {
long double d;
long long i;
} f;
f.d = x;
if((f.i & 0x7fffffffffffffffffffffffffffffff) == 0) {
return FP_ZERO;
}
if((f.i & 0x7fff0000000000000000000000000000) == 0 && (f.i & 0xffffffffffffffffffffffffffff != 0)) {
return FP_SUBNORMAL;
}
if((f.i & 0x7fff0000000000000000000000000000) == 0x7fff0000000000000000000000000000) {
if((f.i & 0xffffffffffffffffffffffffffff) == 0) {
return FP_INFINITE;
}
else {
return FP_NAN;
}
}
return FP_NORMAL;
}

34
math/__signbit.c Normal file
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@ -0,0 +1,34 @@
#include <math.h>
int __signbitd(double x) {
union fp {
double d;
long i;
} f;
f.d = x;
return f.i & 0x8000000000000000;
}
int __signbitf(float x) {
union fp {
float f;
int i;
} f;
f.f = x;
return f.i & 0x80000000;
}
int __signbitl(long double x) {
union fp {
long double d;
long long i;
} f;
f.d = x;
return f.i & 0x80000000000000000000000000000000;
}