none/tests/arm64/fmadd_sub.c

   1 #include <math.h>
   2 #include <stdint.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5
   6 #define COUNT 5
   7
   8 static void
   9 print_float(const char *ident, float x)
  10 {
  11   union
  12   {
  13     float f;
  14     uint32_t i;
  15   } u;
  16
  17   u.f = x;
  18   printf("%s = %08x = %.17g\n", ident, u.i, x);
  19 }
  20
  21 static void
  22 print_double(const char *ident, double x)
  23 {
  24   union
  25   {
  26     double f;
  27     uint64_t i;
  28   } u;
  29
  30   u.f = x;
  31   printf("%s = %016lx = %.17g\n", ident, u.i, x);
  32 }
  33
  34 int
  35 main(int argc, char **argv)
  36 {
  37   float x[] = { 55,                  0.98076171874999996, 0, 1, 0xFFFFFFFF } ;
  38   float y[] = { 0.69314718055994529, 1.015625,            0, 1, 0xFFFFFFFF };
  39   float z[] = { 38.123094930796988,  1,                   0, 1, 0xFFFFFFFF };
  40   float dst = -5;
  41
  42   double dx[] = { 55,                  0.98076171874999996, 0, 1, 0xFFFFFFFF } ;
  43   double dy[] = { 0.69314718055994529, 1.015625,            0, 1, 0xFFFFFFFF };
  44   double dz[] = { 38.123094930796988,  1,                   0, 1, 0xFFFFFFFF };
  45   double ddst= -5;
  46
  47   int i;
  48
  49   for (i = 0; i < COUNT; i++) {
  50           //32bit variant
  51           asm("fmadd %s0, %s1, %s2, %s3\n;" : "=w"(dst) : "w"(x[i]), "w"(y[i]), "w"(z[i]));
  52           printf("FMADD 32bit: dst = z + x * y\n");
  53           printf("%f = %f + %f * %f\n", dst, z[i], x[i], y[i]);
  54           print_float("dst", dst);
  55
  56           // Floating-point negated fused multiply-add
  57           asm("fnmadd %s0, %s1, %s2, %s3\n;" : "=w"(dst) : "w"(x[i]), "w"(y[i]), "w"(z[i]));
  58           printf("FNMADD 32bit: dst = -z + (-x) * y\n");
  59           printf("%f = -%f + (-%f) * %f\n", dst, z[i], x[i], y[i]);
  60           print_float("dst", dst);
  61
  62           asm("fmsub %s0, %s1, %s2, %s3\n;" : "=w"(dst) : "w"(x[i]), "w"(y[i]), "w"(z[i]));
  63           printf("FMSUB 32bit: dst = z + (-x) * y\n");
  64           printf("%f = %f + (-%f) * %f\n", dst, z[i], x[i], y[i]);
  65           print_float("dst", dst);
  66
  67           asm("fnmsub %s0, %s1, %s2, %s3\n;" : "=w"(dst) : "w"(x[i]), "w"(y[i]), "w"(z[i]));
  68           printf("FNMSUB 32bit: dst = -z + x * y\n");
  69           printf("%f = -%f + %f * %f\n", dst, z[i], x[i], y[i]);
  70           print_float("dst", dst);
  71
  72           //64bit variant
  73           asm("fmadd %d0, %d1, %d2, %d3\n;" : "=w"(ddst) : "w"(dx[i]), "w"(dy[i]), "w"(dz[i]));
  74           printf("FMADD 64bit: dst = z + x * y\n");
  75           printf("%f = %f + %f * %f\n", ddst, dz[i], dx[i], dy[i]);
  76           print_double("dst", ddst);
  77
  78           asm("fnmadd %d0, %d1, %d2, %d3\n;" : "=w"(ddst) : "w"(dx[i]), "w"(dy[i]), "w"(dz[i]));
  79           printf("FNMADD 64bit: dst = -z + (-x) * y\n");
  80           printf("%f = -%f - %f * %f\n", ddst, dz[i], dx[i], dy[i]);
  81           print_double("dst", ddst);
  82
  83           asm("fmsub %d0, %d1, %d2, %d3\n;" : "=w"(ddst) : "w"(dx[i]), "w"(dy[i]), "w"(dz[i]));
  84           printf("FMSUB 64bit: dst = z + (-x) * y\n");
  85           printf("%f = %f + (-%f) * %f\n", ddst, dz[i], dx[i], dy[i]);
  86           print_double("dst", ddst);
  87
  88           asm("fnmsub %d0, %d1, %d2, %d3\n;" : "=w"(ddst) : "w"(dx[i]), "w"(dy[i]), "w"(dz[i]));
  89           printf("FNMSUB 64bit: dst = -z + x * y\n");
  90           printf("%f = -%f + %f * %f\n", ddst, dz[i], dx[i], dy[i]);
  91           print_double("dst", ddst);
  92
  93           printf("\n");
  94   }
  95
  96   return 0;
  97 }
  98