| 1 | /* |
| 2 | * Test floating-point multiply-and-add instructions. |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 5 | */ |
| 6 | #include <fenv.h> |
| 7 | #include <stdbool.h> |
| 8 | #include <stdio.h> |
| 9 | #include <stdlib.h> |
| 10 | #include <string.h> |
| 11 | #include "float.h" |
| 12 | |
| 13 | union val { |
| 14 | float e; |
| 15 | double d; |
| 16 | long double x; |
| 17 | char buf[16]; |
| 18 | }; |
| 19 | |
| 20 | /* |
| 21 | * PoP tables as close to the original as possible. |
| 22 | */ |
| 23 | static const char *table1[N_SIGNED_CLASSES][N_SIGNED_CLASSES] = { |
| 24 | /* -inf -Fn -0 +0 +Fn +inf QNaN SNaN */ |
| 25 | {/* -inf */ "P(+inf)", "P(+inf)", "Xi: T(dNaN)", "Xi: T(dNaN)", "P(-inf)", "P(-inf)", "P(b)", "Xi: T(b*)"}, |
| 26 | {/* -Fn */ "P(+inf)", "P(a*b)", "P(+0)", "P(-0)", "P(a*b)", "P(-inf)", "P(b)", "Xi: T(b*)"}, |
| 27 | {/* -0 */ "Xi: T(dNaN)", "P(+0)", "P(+0)", "P(-0)", "P(-0)", "Xi: T(dNaN)", "P(b)", "Xi: T(b*)"}, |
| 28 | {/* +0 */ "Xi: T(dNaN)", "P(-0)", "P(-0)", "P(+0)", "P(+0)", "Xi: T(dNaN)", "P(b)", "Xi: T(b*)"}, |
| 29 | {/* +Fn */ "P(-inf)", "P(a*b)", "P(-0)", "P(+0)", "P(a*b)", "P(+inf)", "P(b)", "Xi: T(b*)"}, |
| 30 | {/* +inf */ "P(-inf)", "P(-inf)", "Xi: T(dNaN)", "Xi: T(dNaN)", "P(+inf)", "P(+inf)", "P(b)", "Xi: T(b*)"}, |
| 31 | {/* QNaN */ "P(a)", "P(a)", "P(a)", "P(a)", "P(a)", "P(a)", "P(a)", "Xi: T(b*)"}, |
| 32 | {/* SNaN */ "Xi: T(a*)", "Xi: T(a*)", "Xi: T(a*)", "Xi: T(a*)", "Xi: T(a*)", "Xi: T(a*)", "Xi: T(a*)", "Xi: T(a*)"}, |
| 33 | }; |
| 34 | |
| 35 | static const char *table2[N_SIGNED_CLASSES][N_SIGNED_CLASSES] = { |
| 36 | /* -inf -Fn -0 +0 +Fn +inf QNaN SNaN */ |
| 37 | {/* -inf */ "T(-inf)", "T(-inf)", "T(-inf)", "T(-inf)", "T(-inf)", "Xi: T(dNaN)", "T(c)", "Xi: T(c*)"}, |
| 38 | {/* -Fn */ "T(-inf)", "R(p+c)", "R(p)", "R(p)", "R(p+c)", "T(+inf)", "T(c)", "Xi: T(c*)"}, |
| 39 | {/* -0 */ "T(-inf)", "R(c)", "T(-0)", "Rezd", "R(c)", "T(+inf)", "T(c)", "Xi: T(c*)"}, |
| 40 | {/* +0 */ "T(-inf)", "R(c)", "Rezd", "T(+0)", "R(c)", "T(+inf)", "T(c)", "Xi: T(c*)"}, |
| 41 | {/* +Fn */ "T(-inf)", "R(p+c)", "R(p)", "R(p)", "R(p+c)", "T(+inf)", "T(c)", "Xi: T(c*)"}, |
| 42 | {/* +inf */ "Xi: T(dNaN)", "T(+inf)", "T(+inf)", "T(+inf)", "T(+inf)", "T(+inf)", "T(c)", "Xi: T(c*)"}, |
| 43 | {/* QNaN */ "T(p)", "T(p)", "T(p)", "T(p)", "T(p)", "T(p)", "T(p)", "Xi: T(c*)"}, |
| 44 | /* SNaN: can't happen */ |
| 45 | }; |
| 46 | |
| 47 | static void interpret_tables(union val *r, bool *xi, int fmt, |
| 48 | int cls_a, const union val *a, |
| 49 | int cls_b, const union val *b, |
| 50 | int cls_c, const union val *c) |
| 51 | { |
| 52 | const char *spec1 = table1[cls_a][cls_b]; |
| 53 | const char *spec2; |
| 54 | union val p; |
| 55 | int cls_p; |
| 56 | |
| 57 | *xi = false; |
| 58 | |
| 59 | if (strcmp(spec1, "P(-inf)") == 0) { |
| 60 | cls_p = CLASS_MINUS_INF; |
| 61 | } else if (strcmp(spec1, "P(+inf)") == 0) { |
| 62 | cls_p = CLASS_PLUS_INF; |
| 63 | } else if (strcmp(spec1, "P(-0)") == 0) { |
| 64 | cls_p = CLASS_MINUS_ZERO; |
| 65 | } else if (strcmp(spec1, "P(+0)") == 0) { |
| 66 | cls_p = CLASS_PLUS_ZERO; |
| 67 | } else if (strcmp(spec1, "P(a)") == 0) { |
| 68 | cls_p = cls_a; |
| 69 | memcpy(&p, a, sizeof(p)); |
| 70 | } else if (strcmp(spec1, "P(b)") == 0) { |
| 71 | cls_p = cls_b; |
| 72 | memcpy(&p, b, sizeof(p)); |
| 73 | } else if (strcmp(spec1, "P(a*b)") == 0) { |
| 74 | /* |
| 75 | * In the general case splitting fma into multiplication and addition |
| 76 | * doesn't work, but this is the case with our test inputs. |
| 77 | */ |
| 78 | cls_p = cls_a == cls_b ? CLASS_PLUS_FN : CLASS_MINUS_FN; |
| 79 | switch (fmt) { |
| 80 | case 0: |
| 81 | p.e = a->e * b->e; |
| 82 | break; |
| 83 | case 1: |
| 84 | p.d = a->d * b->d; |
| 85 | break; |
| 86 | case 2: |
| 87 | p.x = a->x * b->x; |
| 88 | break; |
| 89 | default: |
| 90 | fprintf(stderr, "Unsupported fmt: %d\n", fmt); |
| 91 | exit(1); |
| 92 | } |
| 93 | } else if (strcmp(spec1, "Xi: T(dNaN)") == 0) { |
| 94 | memcpy(r, default_nans[fmt], sizeof(*r)); |
| 95 | *xi = true; |
| 96 | return; |
| 97 | } else if (strcmp(spec1, "Xi: T(a*)") == 0) { |
| 98 | memcpy(r, a, sizeof(*r)); |
| 99 | snan_to_qnan(r->buf, fmt); |
| 100 | *xi = true; |
| 101 | return; |
| 102 | } else if (strcmp(spec1, "Xi: T(b*)") == 0) { |
| 103 | memcpy(r, b, sizeof(*r)); |
| 104 | snan_to_qnan(r->buf, fmt); |
| 105 | *xi = true; |
| 106 | return; |
| 107 | } else { |
| 108 | fprintf(stderr, "Unsupported spec1: %s\n", spec1); |
| 109 | exit(1); |
| 110 | } |
| 111 | |
| 112 | spec2 = table2[cls_p][cls_c]; |
| 113 | if (strcmp(spec2, "T(-inf)") == 0) { |
| 114 | memcpy(r, signed_floats[fmt][CLASS_MINUS_INF].v[0], sizeof(*r)); |
| 115 | } else if (strcmp(spec2, "T(+inf)") == 0) { |
| 116 | memcpy(r, signed_floats[fmt][CLASS_PLUS_INF].v[0], sizeof(*r)); |
| 117 | } else if (strcmp(spec2, "T(-0)") == 0) { |
| 118 | memcpy(r, signed_floats[fmt][CLASS_MINUS_ZERO].v[0], sizeof(*r)); |
| 119 | } else if (strcmp(spec2, "T(+0)") == 0 || strcmp(spec2, "Rezd") == 0) { |
| 120 | memcpy(r, signed_floats[fmt][CLASS_PLUS_ZERO].v[0], sizeof(*r)); |
| 121 | } else if (strcmp(spec2, "R(c)") == 0 || strcmp(spec2, "T(c)") == 0) { |
| 122 | memcpy(r, c, sizeof(*r)); |
| 123 | } else if (strcmp(spec2, "R(p)") == 0 || strcmp(spec2, "T(p)") == 0) { |
| 124 | memcpy(r, &p, sizeof(*r)); |
| 125 | } else if (strcmp(spec2, "R(p+c)") == 0 || strcmp(spec2, "T(p+c)") == 0) { |
| 126 | switch (fmt) { |
| 127 | case 0: |
| 128 | r->e = p.e + c->e; |
| 129 | break; |
| 130 | case 1: |
| 131 | r->d = p.d + c->d; |
| 132 | break; |
| 133 | case 2: |
| 134 | r->x = p.x + c->x; |
| 135 | break; |
| 136 | default: |
| 137 | fprintf(stderr, "Unsupported fmt: %d\n", fmt); |
| 138 | exit(1); |
| 139 | } |
| 140 | } else if (strcmp(spec2, "Xi: T(dNaN)") == 0) { |
| 141 | memcpy(r, default_nans[fmt], sizeof(*r)); |
| 142 | *xi = true; |
| 143 | } else if (strcmp(spec2, "Xi: T(c*)") == 0) { |
| 144 | memcpy(r, c, sizeof(*r)); |
| 145 | snan_to_qnan(r->buf, fmt); |
| 146 | *xi = true; |
| 147 | } else { |
| 148 | fprintf(stderr, "Unsupported spec2: %s\n", spec2); |
| 149 | exit(1); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | struct iter { |
| 154 | int fmt; |
| 155 | int cls[3]; |
| 156 | int val[3]; |
| 157 | }; |
| 158 | |
| 159 | static bool iter_next(struct iter *it) |
| 160 | { |
| 161 | int i; |
| 162 | |
| 163 | for (i = 2; i >= 0; i--) { |
| 164 | if (++it->val[i] != signed_floats[it->fmt][it->cls[i]].n) { |
| 165 | return true; |
| 166 | } |
| 167 | it->val[i] = 0; |
| 168 | |
| 169 | if (++it->cls[i] != N_SIGNED_CLASSES) { |
| 170 | return true; |
| 171 | } |
| 172 | it->cls[i] = 0; |
| 173 | } |
| 174 | |
| 175 | return ++it->fmt != N_FORMATS; |
| 176 | } |
| 177 | |
| 178 | int main(void) |
| 179 | { |
| 180 | int ret = EXIT_SUCCESS; |
| 181 | struct iter it = {}; |
| 182 | |
| 183 | do { |
| 184 | size_t n = float_sizes[it.fmt]; |
| 185 | union val a, b, c, exp, res; |
| 186 | bool xi_exp, xi; |
| 187 | |
| 188 | memcpy(&a, signed_floats[it.fmt][it.cls[0]].v[it.val[0]], sizeof(a)); |
| 189 | memcpy(&b, signed_floats[it.fmt][it.cls[1]].v[it.val[1]], sizeof(b)); |
| 190 | memcpy(&c, signed_floats[it.fmt][it.cls[2]].v[it.val[2]], sizeof(c)); |
| 191 | |
| 192 | interpret_tables(&exp, &xi_exp, it.fmt, |
| 193 | it.cls[1], &b, it.cls[2], &c, it.cls[0], &a); |
| 194 | |
| 195 | memcpy(&res, &a, sizeof(res)); |
| 196 | feclearexcept(FE_ALL_EXCEPT); |
| 197 | switch (it.fmt) { |
| 198 | case 0: |
| 199 | asm("maebr %[a],%[b],%[c]" |
| 200 | : [a] "+f" (res.e) : [b] "f" (b.e), [c] "f" (c.e)); |
| 201 | break; |
| 202 | case 1: |
| 203 | asm("madbr %[a],%[b],%[c]" |
| 204 | : [a] "+f" (res.d) : [b] "f" (b.d), [c] "f" (c.d)); |
| 205 | break; |
| 206 | case 2: |
| 207 | asm("wfmaxb %[a],%[c],%[b],%[a]" |
| 208 | : [a] "+v" (res.x) : [b] "v" (b.x), [c] "v" (c.x)); |
| 209 | break; |
| 210 | default: |
| 211 | fprintf(stderr, "Unsupported fmt: %d\n", it.fmt); |
| 212 | exit(1); |
| 213 | } |
| 214 | xi = fetestexcept(FE_ALL_EXCEPT) == FE_INVALID; |
| 215 | |
| 216 | if (memcmp(&res, &exp, n) != 0 || xi != xi_exp) { |
| 217 | fprintf(stderr, "[ FAILED ] "); |
| 218 | dump_v(stderr, &b, n); |
| 219 | fprintf(stderr, " * "); |
| 220 | dump_v(stderr, &c, n); |
| 221 | fprintf(stderr, " + "); |
| 222 | dump_v(stderr, &a, n); |
| 223 | fprintf(stderr, ": actual="); |
| 224 | dump_v(stderr, &res, n); |
| 225 | fprintf(stderr, "/%d, expected=", (int)xi); |
| 226 | dump_v(stderr, &exp, n); |
| 227 | fprintf(stderr, "/%d\n", (int)xi_exp); |
| 228 | ret = EXIT_FAILURE; |
| 229 | } |
| 230 | } while (iter_next(&it)); |
| 231 | |
| 232 | return ret; |
| 233 | } |