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#if 0 /*
#/ ================================================================
#/
#/ rf64.c
#/
#/ Probabalistic floating-point numbers
#/
#/ ----------------------------------------------------------------
#/
#/ (C) 2024 Mitya Selivanov <guattari.tech>, MIT License
#/
#/ ================================================================
#/
#/ Self-compilation shell script
#/
SRC=${0##*./}
BIN=${SRC%.*}
gcc \
-Wall -Wextra -Werror -pedantic \
-Wno-old-style-declaration \
-Wno-missing-braces \
-Wno-unused-variable \
-Wno-unused-but-set-variable \
-Wno-unused-parameter \
-Wno-overlength-strings \
-O3 \
-fsanitize=undefined,address,leak -mshstk \
-D RF64_TESTS \
-o $BIN $SRC && \
./$BIN $@ && rm $BIN
exit $? # */
#endif
// ================================================================
#ifndef TYPES_HEADER_GUARD_
#define TYPES_HEADER_GUARD_
typedef signed char i8;
typedef signed short i16;
typedef signed i32;
typedef signed long long i64;
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned u32;
typedef unsigned long long u64;
typedef char c8;
typedef int c32;
typedef signed char b8;
typedef float f32;
typedef double f64;
#endif // TYPES_HEADER_GUARD_
// ================================================================
#ifndef RF64_HEADER_GUARD_
#define RF64_HEADER_GUARD_
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <assert.h>
#include <stdlib.h>
#ifndef RF64_RAND
static i32 rf64_rand(i32 min, i32 max) {
if (max <= min)
return min;
return min + (rand() % (max - min + 1));
}
#define RF64_RAND(min, max) rf64_rand((min), (max))
#endif
#define RF64_EXPONENT_NUM_BITS 30
#define RF64_MANTISSA_NUM_BITS 32
#define RF64_EXPONENT_ZERO (1 << (RF64_EXPONENT_NUM_BITS / 2))
#define RF64_EXPONENT_MAX ((1 << RF64_EXPONENT_NUM_BITS) - 1)
#define RF64_MANTISSA_MAX 0xffffffffu
typedef struct {
u32 infinity : 1;
u32 sign : 1;
i32 exponent : RF64_EXPONENT_NUM_BITS;
u32 mantissa;
} rf64;
rf64 rf64_from_i64(i64 x);
i64 i64_from_rf64(rf64 x);
void rf64_inc(rf64 *x);
void rf64_dec(rf64 *x);
void rf64_add(rf64 *x, rf64 y);
void rf64_sub(rf64 *x, rf64 y);
void rf64_mul(rf64 *x, rf64 y);
void rf64_div(rf64 *x, rf64 y);
#endif // RF64_HEADER_GUARD_
#ifndef RF64_HEADER
#ifndef RF64_IMPL_GUARD_
#define RF64_IMPL_GUARD_
rf64 rf64_from_i64(i64 x) {
rf64 z = {
.sign = x < 0,
.exponent = RF64_EXPONENT_ZERO,
};
u64 a = z.sign ? -x : x;
while (a > RF64_MANTISSA_MAX) {
u64 loss_comp = (a & 1) == 1 ? RF64_RAND(0, 1) : 0;
z.exponent += 1;
a /= 2;
a += loss_comp;
}
z.mantissa = (u32) a;
return z;
}
i64 i64_from_rf64(rf64 x) {
assert(0);
}
void rf64_inc(rf64 *x) {
assert(0);
}
void rf64_dec(rf64 *x) {
assert(x != NULL);
if (x == NULL) return;
assert(0);
}
void rf64_add(rf64 *x, rf64 y) {
assert(x != NULL);
if (x == NULL) return;
assert(0);
}
void rf64_sub(rf64 *x, rf64 y) {
assert(x != NULL);
if (x == NULL) return;
assert(0);
}
void rf64_mul(rf64 *x, rf64 y) {
assert(x != NULL);
if (x == NULL) return;
assert(0);
}
void rf64_div(rf64 *x, rf64 y) {
assert(x != NULL);
if (x == NULL) return;
assert(0);
}
#ifdef RF64_TESTS
#include <stdio.h>
#include <string.h>
void report_test(c8 *name, b8 success) {
i32 l = 20 - (i32) strlen(name);
printf("%s %.*s %s\n",
name,
l < 1 ? 1 : l,
"....................",
success ? "OK" : "FAIL"
);
}
#define TEST_(x) report_test(#x, test_##x())
b8 test_from_i64() {
return 1
&& rf64_from_i64( 0 ).infinity == 0
&& rf64_from_i64( 0 ).sign == 0
&& rf64_from_i64( 0 ).exponent == RF64_EXPONENT_ZERO
&& rf64_from_i64( 0 ).mantissa == 0
&& rf64_from_i64( 42 ).infinity == 0
&& rf64_from_i64( 42 ).sign == 0
&& rf64_from_i64( 42 ).exponent == RF64_EXPONENT_ZERO
&& rf64_from_i64( 42 ).mantissa == 42
&& rf64_from_i64(-42 ).infinity == 0
&& rf64_from_i64(-42 ).sign == 1
&& rf64_from_i64(-42 ).exponent == RF64_EXPONENT_ZERO
&& rf64_from_i64(-42 ).mantissa == 42
&& rf64_from_i64( 0xffffffff ).infinity == 0
&& rf64_from_i64( 0xffffffff ).sign == 0
&& rf64_from_i64( 0xffffffff ).exponent == RF64_EXPONENT_ZERO
&& rf64_from_i64( 0xffffffff ).mantissa == 0xffffffff
&& rf64_from_i64(-0xffffffffll ).infinity == 0
&& rf64_from_i64(-0xffffffffll ).sign == 1
&& rf64_from_i64(-0xffffffffll ).exponent == RF64_EXPONENT_ZERO
&& rf64_from_i64(-0xffffffffll ).mantissa == 0xffffffff
&& rf64_from_i64( 0x100000000ll).infinity == 0
&& rf64_from_i64( 0x100000000ll).sign == 0
&& rf64_from_i64( 0x100000000ll).exponent == RF64_EXPONENT_ZERO + 1
&& rf64_from_i64( 0x100000000ll).mantissa == 0x80000000u
&& rf64_from_i64(-0x100000000ll).infinity == 0
&& rf64_from_i64(-0x100000000ll).sign == 1
&& rf64_from_i64(-0x100000000ll).exponent == RF64_EXPONENT_ZERO + 1
&& rf64_from_i64(-0x100000000ll).mantissa == 0x80000000u
&& 1;
}
b8 test_to_i64() {
return 1
&& i64_from_rf64(rf64_from_i64( 0 )) == 0
&& i64_from_rf64(rf64_from_i64( 1 )) == 1
&& i64_from_rf64(rf64_from_i64(-1 )) == -1
&& i64_from_rf64(rf64_from_i64( 42 )) == 42
&& i64_from_rf64(rf64_from_i64(-42 )) == -42
&& i64_from_rf64(rf64_from_i64( 0xffffffff )) == 0xffffffff
&& i64_from_rf64(rf64_from_i64(-0xffffffff )) == -0xffffffff
&& i64_from_rf64(rf64_from_i64( 0x100000000ll )) == 0x100000000ll
&& i64_from_rf64(rf64_from_i64(-0x100000000ll )) == -0x100000000ll
&& i64_from_rf64(rf64_from_i64( 0x42000000000ll)) == 0x42000000000ll
&& i64_from_rf64(rf64_from_i64(-0x42000000000ll)) == -0x42000000000ll
&& 1;
}
i32 main(i32 argc, c8 **argv) {
(void) argc;
(void) argv;
TEST_(from_i64);
TEST_(to_i64);
return 0;
}
#undef TEST_
#endif // RF64_TESTS
#endif // RF64_IMPL_GUARD_
#endif // RF64_HEADER
|
