cvw/examples/fp/softfloat_demo/softfloat_demoSP.c

92 lines
2.6 KiB
C

// softfloat_demo3.c
// james.stine@okstate.edu 15 August 2023
//
// Demonstrate using SoftFloat do compute a floating-point for quad, then print results
#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>
#include <quadmath.h> // GCC Quad-Math Library
#include "softfloat.h"
#include "softfloat_types.h"
typedef union sp {
uint32_t v;
float f;
} sp;
typedef union dp {
uint64_t v;
double d;
} dp;
typedef union qp {
uint64_t v[2];
__float128 q;
} qp;
void printF32 (char *msg, float32_t f) {
sp conv;
int i, j;
conv.v = f.v; // use union to convert between hexadecimal and floating-point views
printf("%s: ", msg); // print out nicely
printf("0x%04x_%04x = %g\n", (conv.v >> 16),(conv.v & 0xFFFF), conv.f);
}
void printF64 (char *msg, float64_t d) {
dp conv;
int i, j;
conv.v = d.v; // use union to convert between hexadecimal and floating-point views
printf("%s: ", msg); // print out nicely
printf("0x%08lx_%08lx = %g\n", (conv.v >> 32),(conv.v & 0xFFFFFFFF), conv.d);
}
void printF128 (char *msg, float128_t q) {
qp conv;
int i, j;
char buf[64];
conv.v[0] = q.v[0]; // use union to convert between hexadecimal and floating-point views
conv.v[1] = q.v[1]; // use union to convert between hexadecimal and floating-point views
printf("%s: ", msg); // print out nicely
//printf("0x%016" PRIx64 "_%016" PRIx64 " = %1.15Qe\n", q.v[1], q.v[0], conv.q);
quadmath_snprintf (buf, sizeof buf, "%1.15Qe", conv.q);
printf("0x%016" PRIx64 "_%016" PRIx64 " = %s\n", q.v[1], q.v[0], buf);
}
void printFlags(void) {
int NX = softfloat_exceptionFlags % 2;
int UF = (softfloat_exceptionFlags >> 1) % 2;
int OF = (softfloat_exceptionFlags >> 2) % 2;
int DZ = (softfloat_exceptionFlags >> 3) % 2;
int NV = (softfloat_exceptionFlags >> 4) % 2;
printf ("Flags: Inexact %d Underflow %d Overflow %d DivideZero %d Invalid %d\n",
NX, UF, OF, DZ, NV);
}
void softfloatInit(void) {
// rounding modes: RNE: softfloat_round_near_even
// RZ: softfloat_round_minMag
// RP: softfloat_round_max
// RM: softfloat_round_min
softfloat_roundingMode = softfloat_round_near_even;
softfloat_exceptionFlags = 0; // clear exceptions
softfloat_detectTininess = softfloat_tininess_afterRounding; // RISC-V behavior for tininess
}
int main() {
float32_t x, y, z;
float32_t r;
x.v = 0xBFFF988E;
y.v = 0x3F8EFFFF;
z.v = 0x40010000;
softfloatInit();
printF32("X", x); printF32("Y", y); printF32("Z", z);
r = f32_mulAdd(x, y, z);
printf("\n");
printF32("r", r);
}