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#include <stdio.h>
#include <math.h>
#include <inttypes.h>
#if defined(__GNUC__)
#define NOINLINE __attribute__((noinline))
#else
#define NOINLINE
#endif
double u64_to_double(uint64_t u64)
{
union {
uint64_t u64;
double dbl;
} u;
u.u64 = u64;
return u.dbl;
}
uint64_t double_to_u64(double x)
{
union {
uint64_t u64;
double dbl;
} u;
u.dbl = x;
return u.u64;
}
NOINLINE
double add(double x, double y)
{
return x + y;
}
NOINLINE
double mul(double x, double y)
{
return x * y;
}
NOINLINE
void add2(double x, double y, double * restrict r1, double * restrict r2)
{
*r1 = x + y;
*r2 = y + x;
}
#if defined(__GNUC__) && defined(__x86_64__)
NOINLINE
double add_x87(double x, double y)
{
asm volatile("fadd %1, %0\n"
: "+t"(x) : "f"(y));
return x;
}
NOINLINE
double mul_x87(double x, double y)
{
asm volatile("fmul %1, %0\n"
: "+t"(x) : "f"(y));
return x;
}
#endif
int main(void)
{
volatile double x = u64_to_double(UINT64_C(0x7ff800000000cafe));
volatile double y = u64_to_double(UINT64_C(0xfff800000000beef));
volatile double snan = u64_to_double(UINT64_C(0x7ff000000000deed));
volatile double snan2 = u64_to_double(UINT64_C(0xfff000000000cafe));
double r1, r2;
add2(x, y, &r1, &r2);
printf(" x = %" PRIx64 "\n", double_to_u64(x));
printf(" y = %" PRIx64 "\n", double_to_u64(y));
printf(" x + y = %" PRIx64 "\n", double_to_u64(add(x, y)));
printf(" y + x = %" PRIx64 "\n", double_to_u64(add(y, x)));
printf("(x + y, y + x) = (%" PRIx64 ", %" PRIx64 ")\n", double_to_u64(r1), double_to_u64(r2));
printf(" x + -x = %" PRIx64 "\n", double_to_u64(add(x, -x)));
printf(" -x + x = %" PRIx64 "\n", double_to_u64(add(-x, x)));
printf(" -x + -x = %" PRIx64 "\n", double_to_u64(add(-x, -x)));
printf(" -x + snan2 = %" PRIx64 "\n", double_to_u64(add(-x, snan2)));
printf(" x + snan2 = %" PRIx64 "\n", double_to_u64(add(x, snan2)));
printf(" -x = %" PRIx64 "\n", double_to_u64(- x));
printf(" -1.0 * x = %" PRIx64 "\n", double_to_u64(mul(-1.0, x)));
printf(" -1.0 * -x = %" PRIx64 "\n", double_to_u64(mul(-1.0, -x)));
printf(" 1.0 * -x = %" PRIx64 "\n", double_to_u64(mul(1.0, -x)));
printf(" -snan = %" PRIx64 "\n", double_to_u64(- snan));
printf("-1.0 * snan = %" PRIx64 "\n", double_to_u64(mul(-1.0, snan)));
printf(" x * y = %" PRIx64 "\n", double_to_u64(mul(x, y)));
printf(" y * x = %" PRIx64 "\n", double_to_u64(mul(y, x)));
printf(" x * -x = %" PRIx64 "\n", double_to_u64(mul(x, -x)));
printf(" -x * x = %" PRIx64 "\n", double_to_u64(mul(-x, x)));
printf(" -x * -x = %" PRIx64 "\n", double_to_u64(mul(-x, -x)));
printf(" -x * snan2 = %" PRIx64 "\n", double_to_u64(mul(-x, snan2)));
printf(" x * snan2 = %" PRIx64 "\n", double_to_u64(mul(x, snan2)));
#if defined(__aarch64__)
{
unsigned int fpcr = __builtin_aarch64_get_fpcr();
__builtin_aarch64_set_fpcr(fpcr | (1u << 25));
fpcr = __builtin_aarch64_get_fpcr();
if (fpcr & (1u << 25)) {
puts("Default NaN mode set");
} else {
puts("Default NaN mode not set");
}
}
printf(" x + y = %" PRIx64 "\n", double_to_u64(add(x, y)));
printf(" y + x = %" PRIx64 "\n", double_to_u64(add(y, x)));
printf(" x + -x = %" PRIx64 "\n", double_to_u64(add(x, -x)));
printf(" -x + x = %" PRIx64 "\n", double_to_u64(add(-x, x)));
printf(" -x + -x = %" PRIx64 "\n", double_to_u64(add(-x, -x)));
printf(" -x + snan2 = %" PRIx64 "\n", double_to_u64(add(-x, snan2)));
printf(" x + snan2 = %" PRIx64 "\n", double_to_u64(add(x, snan2)));
printf(" -x = %" PRIx64 "\n", double_to_u64(- x));
printf(" -1.0 * x = %" PRIx64 "\n", double_to_u64(mul(-1.0, x)));
printf(" -1.0 * -x = %" PRIx64 "\n", double_to_u64(mul(-1.0, -x)));
printf(" 1.0 * -x = %" PRIx64 "\n", double_to_u64(mul(1.0, -x)));
printf(" -snan = %" PRIx64 "\n", double_to_u64(- snan));
printf("-1.0 * snan = %" PRIx64 "\n", double_to_u64(mul(-1.0, snan)));
printf(" x * y = %" PRIx64 "\n", double_to_u64(mul(x, y)));
printf(" y * x = %" PRIx64 "\n", double_to_u64(mul(y, x)));
printf(" x * -x = %" PRIx64 "\n", double_to_u64(mul(x, -x)));
printf(" -x * x = %" PRIx64 "\n", double_to_u64(mul(-x, x)));
printf(" -x * -x = %" PRIx64 "\n", double_to_u64(mul(-x, -x)));
printf(" -x * snan2 = %" PRIx64 "\n", double_to_u64(mul(-x, snan2)));
printf(" x * snan2 = %" PRIx64 "\n", double_to_u64(mul(x, snan2)));
#elif defined(__GNUC__) && defined(__x86_64__)
puts("x87 FPU:");
printf(" x + y = %" PRIx64 "\n", double_to_u64(add_x87(x, y)));
printf(" y + x = %" PRIx64 "\n", double_to_u64(add_x87(y, x)));
printf(" x + -x = %" PRIx64 "\n", double_to_u64(add_x87(x, -x)));
printf(" -x + x = %" PRIx64 "\n", double_to_u64(add_x87(-x, x)));
printf(" -x + -x = %" PRIx64 "\n", double_to_u64(add_x87(-x, -x)));
printf(" -x + snan2 = %" PRIx64 "\n", double_to_u64(add_x87(-x, snan2)));
printf(" x + snan2 = %" PRIx64 "\n", double_to_u64(add_x87(x, snan2)));
printf(" -1.0 * x = %" PRIx64 "\n", double_to_u64(mul_x87(-1.0, x)));
printf(" -1.0 * -x = %" PRIx64 "\n", double_to_u64(mul_x87(-1.0, -x)));
printf(" 1.0 * -x = %" PRIx64 "\n", double_to_u64(mul_x87(1.0, -x)));
printf("-1.0 * snan = %" PRIx64 "\n", double_to_u64(mul_x87(-1.0, snan)));
printf(" x * y = %" PRIx64 "\n", double_to_u64(mul_x87(x, y)));
printf(" y * x = %" PRIx64 "\n", double_to_u64(mul_x87(y, x)));
printf(" x * -x = %" PRIx64 "\n", double_to_u64(mul_x87(x, -x)));
printf(" -x * x = %" PRIx64 "\n", double_to_u64(mul_x87(-x, x)));
printf(" -x * -x = %" PRIx64 "\n", double_to_u64(mul_x87(-x, -x)));
printf(" -x * snan2 = %" PRIx64 "\n", double_to_u64(mul_x87(-x, snan2)));
printf(" x * snan2 = %" PRIx64 "\n", double_to_u64(mul_x87(x, snan2)));
#endif
}
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