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#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#define FFLAG_NX_SHIFT 0 /* inexact */
#define FFLAG_UF_SHIFT 1 /* underflow */
#define FFLAG_OF_SHIFT 2 /* overflow */
#define FFLAG_DZ_SHIFT 3 /* divide by zero */
#define FFLAG_NV_SHIFT 4 /* invalid operation */
#define FFLAG_NV (1UL << FFLAG_NV_SHIFT)
#define FFLAG_DZ (1UL << FFLAG_DZ_SHIFT)
#define FFLAG_OF (1UL << FFLAG_OF_SHIFT)
#define FFLAG_UF (1UL << FFLAG_UF_SHIFT)
#define FFLAG_NX (1UL << FFLAG_NX_SHIFT)
typedef struct fp64_fcvt_fcvtmod_testcase {
const char* name;
union {
uint64_t inp_lu;
double inp_lf;
};
uint64_t exp_fcvt;
uint8_t exp_fcvt_fflags;
uint64_t exp_fcvtmod;
uint8_t exp_fcvtmod_fflags;
} fp64_fcvt_fcvtmod_testcase_t;
void print_fflags(uint8_t fflags)
{
int set = 0;
if (fflags == 0) {
printf("-");
return;
}
if (fflags & FFLAG_NV) {
printf("%sFFLAG_NV", set ? " | " : "");
set = 1;
}
if (fflags & FFLAG_DZ) {
printf("%sFFLAG_DZ", set ? " | " : "");
set = 1;
}
if (fflags & FFLAG_OF) {
printf("%sFFLAG_OF", set ? " | " : "");
set = 1;
}
if (fflags & FFLAG_UF) {
printf("%sFFLAG_UF", set ? " | " : "");
set = 1;
}
if (fflags & FFLAG_NX) {
printf("%sFFLAG_NX", set ? " | " : "");
set = 1;
}
}
/* Clear all FP flags. */
static inline void clear_fflags()
{
__asm__ __volatile__("fsflags zero");
}
/* Read all FP flags. */
static inline uint8_t get_fflags()
{
uint64_t v;
__asm__ __volatile__("frflags %0" : "=r"(v));
return (uint8_t)v;
}
/* Move input value (without conversations) into an FP register. */
static inline double do_fmv_d_x(uint64_t inp)
{
double fpr;
__asm__ __volatile__("fmv.d.x %0, %1" : "=f"(fpr) : "r"(inp));
return fpr;
}
static inline uint64_t do_fcvt_w_d(uint64_t inp, uint8_t *fflags)
{
uint64_t ret;
double fpr = do_fmv_d_x(inp);
clear_fflags();
__asm__ __volatile__("fcvt.w.d %0, %1, rtz" : "=r"(ret) : "f"(fpr));
*fflags = get_fflags();
return ret;
}
static inline uint64_t do_fcvtmod_w_d(uint64_t inp, uint8_t *fflags)
{
uint64_t ret;
double fpr = do_fmv_d_x(inp);
clear_fflags();
/* fcvtmod.w.d rd, rs1, rtz = 1100001 01000 rs1 001 rd 1010011 */
asm(".insn r 0x53, 0x1, 0x61, %0, %1, f8" : "=r"(ret) : "f"(fpr));
*fflags = get_fflags();
return ret;
}
static const fp64_fcvt_fcvtmod_testcase_t tests[] = {
/* Zero (exp=0, frac=0) */
{ .name = "+0.0",
.inp_lf = 0x0p0,
.exp_fcvt = 0x0000000000000000,
.exp_fcvt_fflags = 0,
.exp_fcvtmod = 0x0000000000000000,
.exp_fcvtmod_fflags = 0 },
{ .name = "-0.0",
.inp_lf = -0x0p0,
.exp_fcvt = 0x0000000000000000,
.exp_fcvt_fflags = 0,
.exp_fcvtmod = 0x0000000000000000,
.exp_fcvtmod_fflags = 0 },
/* Subnormal: exp=0 frac!=0 */
{ .name = "Subnormal frac=1",
.inp_lu = 0x0000000000000001,
.exp_fcvt = 0x0000000000000000,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "Subnormal frac=0xf..f",
.inp_lu = 0x0000ffffffffffff,
.exp_fcvt = 0x0000000000000000,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "Neg subnormal frac=1",
.inp_lu = 0x0000000000000001,
.exp_fcvt = 0x0000000000000000,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "Neg subnormal frac=0xf..f",
.inp_lu = 0x8000ffffffffffff,
.exp_fcvt = 0x0000000000000000,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
/* Infinity: exp=0x7ff, frac=0 */
{ .name = "+INF",
.inp_lu = 0x7ff0000000000000,
.exp_fcvt = 0x000000007fffffff, /* int32 max */
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NV },
{ .name = "-INF",
.inp_lu = 0xfff0000000000000,
.exp_fcvt = 0xffffffff80000000, /* int32 min */
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NV },
/* NaN: exp=7ff, frac!=0 */
{ .name = "canonical NaN",
.inp_lu = 0x7ff8000000000000,
.exp_fcvt = 0x000000007fffffff, /* int32 max */
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NV },
{ .name = "non-canonical NaN",
.inp_lu = 0x7ff8000000100000,
.exp_fcvt = 0x000000007fffffff, /* int32 min */
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NV },
/* Normal numbers: exp!=0, exp!=7ff */
{ .name = "+smallest normal value",
.inp_lu = 0x0010000000000000,
.exp_fcvt = 0,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "-smallest normal value",
.inp_lu = 0x8010000000000000,
.exp_fcvt = 0,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "+0.5",
.inp_lf = 0x1p-1,
.exp_fcvt = 0,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "-0.5",
.inp_lf = -0x1p-1,
.exp_fcvt = 0,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "+value just below 1.0",
.inp_lu = 0x3fefffffffffffff,
.exp_fcvt = 0,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "-value just above -1.0",
.inp_lu = 0xbfefffffffffffff,
.exp_fcvt = 0,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "+1.0",
.inp_lf = 0x1p0,
.exp_fcvt = 0x0000000000000001,
.exp_fcvt_fflags = 0,
.exp_fcvtmod = 0x0000000000000001,
.exp_fcvtmod_fflags = 0 },
{ .name = "-1.0",
.inp_lf = -0x1p0,
.exp_fcvt = 0xffffffffffffffff,
.exp_fcvt_fflags = 0,
.exp_fcvtmod = 0xffffffffffffffff,
.exp_fcvtmod_fflags = 0 },
{ .name = "+1.5",
.inp_lu = 0x3ff8000000000000,
.exp_fcvt = 1,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 1,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "-1.5",
.inp_lu = 0xbff8000000000000,
.exp_fcvt = 0xffffffffffffffff,
.exp_fcvt_fflags = FFLAG_NX,
.exp_fcvtmod = 0xffffffffffffffff,
.exp_fcvtmod_fflags = FFLAG_NX },
{ .name = "+max int32 (2147483647)",
.inp_lu = 0x41dfffffffc00000,
.exp_fcvt = 0x000000007fffffff,
.exp_fcvt_fflags = 0,
.exp_fcvtmod = 0x000000007fffffff,
.exp_fcvtmod_fflags = 0 },
{ .name = "+max int32 +1 (2147483648)",
.inp_lf = 0x1p31,
.exp_fcvt = 0x000000007fffffff,
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = (uint64_t)-2147483648l, /* int32 min */
.exp_fcvtmod_fflags = FFLAG_NV },
{ .name = "+max int32 +2 (2147483649)",
.inp_lu = 0x41e0000000200000,
.exp_fcvt = 0x000000007fffffff,
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = (uint64_t)-2147483647l, /* int32 min +1 */
.exp_fcvtmod_fflags = FFLAG_NV },
{ .name = "-max int32 (-2147483648)",
.inp_lf = -0x1p31,
.exp_fcvt = 0xffffffff80000000,
.exp_fcvt_fflags = 0,
.exp_fcvtmod = 0xffffffff80000000,
.exp_fcvtmod_fflags = 0 },
{ .name = "-max int32 -1 (-2147483649)",
.inp_lf = -0x1.00000002p+31,
.exp_fcvt = 0xffffffff80000000,
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = 2147483647, /* int32 max */
.exp_fcvtmod_fflags = FFLAG_NV },
{ .name = "-max int32 -2 (-2147483650)",
.inp_lf = -0x1.00000004p+31,
.exp_fcvt = 0xffffffff80000000,
.exp_fcvt_fflags = FFLAG_NV,
.exp_fcvtmod = 2147483646, /* int32 max -1 */
.exp_fcvtmod_fflags = FFLAG_NV },
};
int run_fcvtmod_tests()
{
uint64_t act_fcvt;
uint8_t act_fcvt_fflags;
uint64_t act_fcvtmod;
uint8_t act_fcvtmod_fflags;
for (size_t i = 0; i < sizeof(tests)/sizeof(tests[0]); i++) {
const fp64_fcvt_fcvtmod_testcase_t *t = &tests[i];
act_fcvt = do_fcvt_w_d(t->inp_lu, &act_fcvt_fflags);
int fcvt_correct = act_fcvt == t->exp_fcvt &&
act_fcvt_fflags == t->exp_fcvt_fflags;
act_fcvtmod = do_fcvtmod_w_d(t->inp_lu, &act_fcvtmod_fflags);
int fcvtmod_correct = act_fcvtmod == t->exp_fcvtmod &&
act_fcvtmod_fflags == t->exp_fcvtmod_fflags;
if (fcvt_correct && fcvtmod_correct) {
continue;
}
printf("Test %zu (%s) failed!\n", i, t->name);
double fpr = do_fmv_d_x(t->inp_lu);
printf("inp_lu: 0x%016lx == %lf\n", t->inp_lu, fpr);
printf("inp_lf: %lf\n", t->inp_lf);
uint32_t sign = (t->inp_lu >> 63);
uint32_t exp = (uint32_t)(t->inp_lu >> 52) & 0x7ff;
uint64_t frac = t->inp_lu & 0xfffffffffffffull; /* significand */
int true_exp = exp - 1023;
int shift = true_exp - 52;
uint64_t true_frac = frac | 1ull << 52;
printf("sign=%d, exp=0x%03x, frac=0x%012lx\n", sign, exp, frac);
printf("true_exp=%d, shift=%d, true_frac=0x%016lx\n", true_exp, shift, true_frac);
if (!fcvt_correct) {
printf("act_fcvt: 0x%016lx == %li\n", act_fcvt, act_fcvt);
printf("exp_fcvt: 0x%016lx == %li\n", t->exp_fcvt, t->exp_fcvt);
printf("act_fcvt_fflags: "); print_fflags(act_fcvt_fflags); printf("\n");
printf("exp_fcvt_fflags: "); print_fflags(t->exp_fcvt_fflags); printf("\n");
}
if (!fcvtmod_correct) {
printf("act_fcvtmod: 0x%016lx == %li\n", act_fcvtmod, act_fcvtmod);
printf("exp_fcvtmod: 0x%016lx == %li\n", t->exp_fcvtmod, t->exp_fcvtmod);
printf("act_fcvtmod_fflags: "); print_fflags(act_fcvtmod_fflags); printf("\n");
printf("exp_fcvtmod_fflags: "); print_fflags(t->exp_fcvtmod_fflags); printf("\n");
}
return 1;
}
return 0;
}
int main()
{
return run_fcvtmod_tests();
}
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