/*
* Test Floating Point Conversion
*/
/* we want additional float type definitions */
#define __STDC_WANT_IEC_60559_BFP_EXT__
#define __STDC_WANT_IEC_60559_TYPES_EXT__
#include <stdio.h>
#include <inttypes.h>
#include <math.h>
#include <float.h>
#include <fenv.h>
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
static char flag_str[256];
static char *get_flag_state(int flags)
{
if (flags) {
snprintf(flag_str, sizeof(flag_str), "%s %s %s %s %s",
flags & FE_OVERFLOW ? "OVERFLOW" : "",
flags & FE_UNDERFLOW ? "UNDERFLOW" : "",
flags & FE_DIVBYZERO ? "DIV0" : "",
flags & FE_INEXACT ? "INEXACT" : "",
flags & FE_INVALID ? "INVALID" : "");
} else {
snprintf(flag_str, sizeof(flag_str), "OK");
}
return flag_str;
}
static void print_double_number(int i, double num)
{
uint64_t double_as_hex = *(uint64_t *) #
int flags = fetestexcept(FE_ALL_EXCEPT);
char *fstr = get_flag_state(flags);
printf("%02d DOUBLE: %02.20e / %#020" PRIx64 " (%#x => %s)\n",
i, num, double_as_hex, flags, fstr);
}
static void print_single_number(int i, float num)
{
uint32_t single_as_hex = *(uint32_t *) #
int flags = fetestexcept(FE_ALL_EXCEPT);
char *fstr = get_flag_state(flags);
printf("%02d SINGLE: %02.20e / %#010x (%#x => %s)\n",
i, num, single_as_hex, flags, fstr);
}
static void print_half_number(int i, uint16_t num)
{
int flags = fetestexcept(FE_ALL_EXCEPT);
char *fstr = get_flag_state(flags);
printf("%02d HALF: %#04x (%#x => %s)\n",
i, num, flags, fstr);
}
static void print_int64(int i, int64_t num)
{
uint64_t int64_as_hex = *(uint64_t *) #
int flags = fetestexcept(FE_ALL_EXCEPT);
char *fstr = get_flag_state(flags);
printf("%02d INT64: %20" PRId64 "/%#020" PRIx64 " (%#x => %s)\n",
i, num, int64_as_hex, flags, fstr);
}
#ifndef SNANF
/* Signaling NaN macros, if supported. */
# define SNANF (__builtin_nansf (""))
# define SNAN (__builtin_nans (""))
# define SNANL (__builtin_nansl (""))
#endif
float single_numbers[] = { -SNANF,
-NAN,
-INFINITY,
-FLT_MAX,
-1.111E+31,
-1.111E+30,
-1.08700982e-12,
-1.78051176e-20,
-FLT_MIN,
0.0,
FLT_MIN,
2.98023224e-08,
5.96046E-8, /* min positive FP16 subnormal */
6.09756E-5, /* max subnormal FP16 */
6.10352E-5, /* min positive normal FP16 */
1.0,
1.0009765625, /* smallest float after 1.0 FP16 */
2.0,
M_E, M_PI,
65503.0,
65504.0, /* max FP16 */
65505.0,
131007.0,
131008.0, /* max AFP */
131009.0,
1.111E+30,
FLT_MAX,
INFINITY,
NAN,
SNANF };
static void convert_single_to_half(void)
{
int i;
printf("Converting single-precision to half-precision\n");
for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
float input = single_numbers[i];
feclearexcept(FE_ALL_EXCEPT);
print_single_number(i, input);
#if defined(__arm__)
uint32_t output;
asm("vcvtb.f16.f32 %0, %1" : "=t" (output) : "x" (input));
#else
uint16_t output;
asm("fcvt %h0, %s1" : "=w" (output) : "x" (input));
#endif
print_half_number(i, output);
}
}
static void convert_single_to_double(void)
{
int i;
printf("Converting single-precision to double-precision\n");
for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
float input = single_numbers[i];
/* uint64_t output; */
double output;
feclearexcept(FE_ALL_EXCEPT);
print_single_number(i, input);
#if defined(__arm__)
asm("vcvt.f64.f32 %P0, %1" : "=w" (output) : "t" (input));
#else
asm("fcvt %d0, %s1" : "=w" (output) : "x" (input));
#endif
print_double_number(i, output);
}
}
static void convert_single_to_integer(void)
{
int i;
printf("Converting single-precision to integer\n");
for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
float input = single_numbers[i];
int64_t output;
feclearexcept(FE_ALL_EXCEPT);
print_single_number(i, input);
#if defined(__arm__)
/* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
output = input;
#else
asm("fcvtzs %0, %s1" : "=r" (output) : "w" (input));
#endif
print_int64(i, output);
}
}
/* This allows us to initialise some doubles as pure hex */
typedef union {
double d;
uint64_t h;
} test_doubles;
test_doubles double_numbers[] = {
{SNAN},
{-NAN},
{-INFINITY},
{-DBL_MAX},
{-FLT_MAX-1.0},
{-FLT_MAX},
{-1.111E+31},
{-1.111E+30}, /* half prec */
{-2.0}, {-1.0},
{-DBL_MIN},
{-FLT_MIN},
{0.0},
{FLT_MIN},
{2.98023224e-08},
{5.96046E-8}, /* min positive FP16 subnormal */
{6.09756E-5}, /* max subnormal FP16 */
{6.10352E-5}, /* min positive normal FP16 */
{1.0},
{1.0009765625}, /* smallest float after 1.0 FP16 */
{DBL_MIN},
{1.3789972848607228e-308},
{1.4914738736681624e-308},
{1.0}, {2.0},
{M_E}, {M_PI},
{65503.0},
{65504.0}, /* max FP16 */
{65505.0},
{131007.0},
{131008.0}, /* max AFP */
{131009.0},
{.h = 0x41dfffffffc00000 }, /* to int = 0x7fffffff */
{FLT_MAX},
{FLT_MAX + 1.0},
{DBL_MAX},
{INFINITY},
{NAN},
{.h = 0x7ff0000000000001}, /* SNAN */
{SNAN},
};
static void convert_double_to_half(void)
{
int i;
printf("Converting double-precision to half-precision\n");
for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
double input = double_numbers[i].d;
uint16_t output;
feclearexcept(FE_ALL_EXCEPT);
print_double_number(i, input);
/* as we don't have _Float16 support */
#if defined(__arm__)
/* asm("vcvtb.f16.f64 %0, %P1" : "=t" (output) : "x" (input)); */
output = input;
#else
asm("fcvt %h0, %d1" : "=w" (output) : "x" (input));
#endif
print_half_number(i, output);
}
}
static void convert_double_to_single(void)
{
int i;
printf("Converting double-precision to single-precision\n");
for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
double input = double_numbers[i].d;
uint32_t output;
feclearexcept(FE_ALL_EXCEPT);
print_double_number(i, input);
#if defined(__arm__)
asm("vcvt.f32.f64 %0, %P1" : "=w" (output) : "x" (input));
#else
asm("fcvt %s0, %d1" : "=w" (output) : "x" (input));
#endif
print_single_number(i, output);
}
}
static void convert_double_to_integer(void)
{
int i;
printf("Converting double-precision to integer\n");
for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
double input = double_numbers[i].d;
int64_t output;
feclearexcept(FE_ALL_EXCEPT);
print_double_number(i, input);
#if defined(__arm__)
/* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
output = input;
#else
asm("fcvtzs %0, %d1" : "=r" (output) : "w" (input));
#endif
print_int64(i, output);
}
}
/* no handy defines for these numbers */
uint16_t half_numbers[] = {
0xffff, /* -NaN / AHP -Max */
0xfcff, /* -NaN / AHP */
0xfc01, /* -NaN / AHP */
0xfc00, /* -Inf */
0xfbff, /* -Max */
0xc000, /* -2 */
0xbc00, /* -1 */
0x8001, /* -MIN subnormal */
0x8000, /* -0 */
0x0000, /* +0 */
0x0001, /* MIN subnormal */
0x3c00, /* 1 */
0x7bff, /* Max */
0x7c00, /* Inf */
0x7c01, /* NaN / AHP */
0x7cff, /* NaN / AHP */
0x7fff, /* NaN / AHP +Max*/
};
static void convert_half_to_double(void)
{
int i;
printf("Converting half-precision to double-precision\n");
for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
uint16_t input = half_numbers[i];
double output;
feclearexcept(FE_ALL_EXCEPT);
print_half_number(i, input);
#if defined(__arm__)
/* asm("vcvtb.f64.f16 %P0, %1" : "=w" (output) : "t" (input)); */
output = input;
#else
asm("fcvt %d0, %h1" : "=w" (output) : "x" (input));
#endif
print_double_number(i, output);
}
}
static void convert_half_to_single(void)
{
int i;
printf("Converting half-precision to single-precision\n");
for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
uint16_t input = half_numbers[i];
float output;
feclearexcept(FE_ALL_EXCEPT);
print_half_number(i, input);
#if defined(__arm__)
asm("vcvtb.f32.f16 %0, %1" : "=w" (output) : "x" ((uint32_t)input));
#else
asm("fcvt %s0, %h1" : "=w" (output) : "x" (input));
#endif
print_single_number(i, output);
}
}
static void convert_half_to_integer(void)
{
int i;
printf("Converting half-precision to integer\n");
for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
uint16_t input = half_numbers[i];
int64_t output;
feclearexcept(FE_ALL_EXCEPT);
print_half_number(i, input);
#if defined(__arm__)
/* asm("vcvt.s32.f16 %0, %1" : "=t" (output) : "t" (input)); v8.2*/
output = input;
#else
asm("fcvt %s0, %h1" : "=w" (output) : "x" (input));
#endif
print_int64(i, output);
}
}
typedef struct {
int flag;
char *desc;
} float_mapping;
float_mapping round_flags[] = {
{ FE_TONEAREST, "to nearest" },
{ FE_UPWARD, "upwards" },
{ FE_DOWNWARD, "downwards" },
{ FE_TOWARDZERO, "to zero" }
};
int main(int argc, char *argv[argc])
{
int i;
printf("#### Enabling IEEE Half Precision\n");
for (i = 0; i < ARRAY_SIZE(round_flags); ++i) {
fesetround(round_flags[i].flag);
printf("### Rounding %s\n", round_flags[i].desc);
convert_single_to_half();
convert_single_to_double();
convert_double_to_half();
convert_double_to_single();
convert_half_to_single();
convert_half_to_double();
}
/* convert to integer */
convert_single_to_integer();
convert_double_to_integer();
convert_half_to_integer();
/* And now with ARM alternative FP16 */
#if defined(__arm__)
/* See glibc sysdeps/arm/fpu_control.h */
asm("mrc p10, 7, r1, cr1, cr0, 0\n\t"
"orr r1, r1, %[flags]\n\t"
"mcr p10, 7, r1, cr1, cr0, 0\n\t"
: /* no output */ : [flags] "n" (1 << 26) : "r1" );
#else
asm("mrs x1, fpcr\n\t"
"orr x1, x1, %[flags]\n\t"
"msr fpcr, x1\n\t"
: /* no output */ : [flags] "n" (1 << 26) : "x1" );
#endif
printf("#### Enabling ARM Alternative Half Precision\n");
for (i = 0; i < ARRAY_SIZE(round_flags); ++i) {
fesetround(round_flags[i].flag);
printf("### Rounding %s\n", round_flags[i].desc);
convert_single_to_half();
convert_single_to_double();
convert_double_to_half();
convert_double_to_single();
convert_half_to_single();
convert_half_to_double();
}
/* convert to integer */
convert_single_to_integer();
convert_double_to_integer();
convert_half_to_integer();
return 0;
}
