diff options
Diffstat (limited to 'fpu')
| -rw-r--r-- | fpu/softfloat-parts.c.inc | 127 | ||||
| -rw-r--r-- | fpu/softfloat.c | 66 |
2 files changed, 166 insertions, 27 deletions
diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc index 73621f4a97..1d09f066c5 100644 --- a/fpu/softfloat-parts.c.inc +++ b/fpu/softfloat-parts.c.inc @@ -204,7 +204,7 @@ static void partsN(canonicalize)(FloatPartsN *p, float_status *status, frac_clear(p); } else { int shift = frac_normalize(p); - p->cls = float_class_normal; + p->cls = float_class_denormal; p->exp = fmt->frac_shift - fmt->exp_bias - shift + !fmt->m68k_denormal; } @@ -334,7 +334,8 @@ static void partsN(uncanon_normal)(FloatPartsN *p, float_status *s, p->frac_lo &= ~round_mask; } frac_shr(p, frac_shift); - } else if (s->flush_to_zero) { + } else if (s->flush_to_zero && + s->ftz_detection == float_ftz_before_rounding) { flags |= float_flag_output_denormal_flushed; p->cls = float_class_zero; exp = 0; @@ -381,11 +382,19 @@ static void partsN(uncanon_normal)(FloatPartsN *p, float_status *s, exp = (p->frac_hi & DECOMPOSED_IMPLICIT_BIT) && !fmt->m68k_denormal; frac_shr(p, frac_shift); - if (is_tiny && (flags & float_flag_inexact)) { - flags |= float_flag_underflow; - } - if (exp == 0 && frac_eqz(p)) { - p->cls = float_class_zero; + if (is_tiny) { + if (s->flush_to_zero) { + assert(s->ftz_detection == float_ftz_after_rounding); + flags |= float_flag_output_denormal_flushed; + p->cls = float_class_zero; + exp = 0; + frac_clear(p); + } else if (flags & float_flag_inexact) { + flags |= float_flag_underflow; + } + if (exp == 0 && frac_eqz(p)) { + p->cls = float_class_zero; + } } } p->exp = exp; @@ -395,7 +404,7 @@ static void partsN(uncanon_normal)(FloatPartsN *p, float_status *s, static void partsN(uncanon)(FloatPartsN *p, float_status *s, const FloatFmt *fmt) { - if (likely(p->cls == float_class_normal)) { + if (likely(is_anynorm(p->cls))) { parts_uncanon_normal(p, s, fmt); } else { switch (p->cls) { @@ -433,9 +442,18 @@ static FloatPartsN *partsN(addsub)(FloatPartsN *a, FloatPartsN *b, bool b_sign = b->sign ^ subtract; int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); + /* + * For addition and subtraction, we will consume an + * input denormal unless the other input is a NaN. + */ + if ((ab_mask & (float_cmask_denormal | float_cmask_anynan)) == + float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + if (a->sign != b_sign) { /* Subtraction */ - if (likely(ab_mask == float_cmask_normal)) { + if (likely(cmask_is_only_normals(ab_mask))) { if (parts_sub_normal(a, b)) { return a; } @@ -468,7 +486,7 @@ static FloatPartsN *partsN(addsub)(FloatPartsN *a, FloatPartsN *b, } } else { /* Addition */ - if (likely(ab_mask == float_cmask_normal)) { + if (likely(cmask_is_only_normals(ab_mask))) { parts_add_normal(a, b); return a; } @@ -488,12 +506,12 @@ static FloatPartsN *partsN(addsub)(FloatPartsN *a, FloatPartsN *b, } if (b->cls == float_class_zero) { - g_assert(a->cls == float_class_normal); + g_assert(is_anynorm(a->cls)); return a; } g_assert(a->cls == float_class_zero); - g_assert(b->cls == float_class_normal); + g_assert(is_anynorm(b->cls)); return_b: b->sign = b_sign; return b; @@ -513,9 +531,13 @@ static FloatPartsN *partsN(mul)(FloatPartsN *a, FloatPartsN *b, int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); bool sign = a->sign ^ b->sign; - if (likely(ab_mask == float_cmask_normal)) { + if (likely(cmask_is_only_normals(ab_mask))) { FloatPartsW tmp; + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + frac_mulw(&tmp, a, b); frac_truncjam(a, &tmp); @@ -541,6 +563,10 @@ static FloatPartsN *partsN(mul)(FloatPartsN *a, FloatPartsN *b, } /* Multiply by 0 or Inf */ + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + if (ab_mask & float_cmask_inf) { a->cls = float_class_inf; a->sign = sign; @@ -596,7 +622,7 @@ static FloatPartsN *partsN(muladd_scalbn)(FloatPartsN *a, FloatPartsN *b, a->sign ^= 1; } - if (unlikely(ab_mask != float_cmask_normal)) { + if (unlikely(!cmask_is_only_normals(ab_mask))) { if (unlikely(ab_mask == float_cmask_infzero)) { float_raise(float_flag_invalid | float_flag_invalid_imz, s); goto d_nan; @@ -611,7 +637,7 @@ static FloatPartsN *partsN(muladd_scalbn)(FloatPartsN *a, FloatPartsN *b, } g_assert(ab_mask & float_cmask_zero); - if (c->cls == float_class_normal) { + if (is_anynorm(c->cls)) { *a = *c; goto return_normal; } @@ -664,6 +690,16 @@ static FloatPartsN *partsN(muladd_scalbn)(FloatPartsN *a, FloatPartsN *b, if (flags & float_muladd_negate_result) { a->sign ^= 1; } + + /* + * All result types except for "return the default NaN + * because this is an Invalid Operation" go through here; + * this matches the set of cases where we consumed a + * denormal input. + */ + if (abc_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } return a; return_sub_zero: @@ -692,7 +728,10 @@ static FloatPartsN *partsN(div)(FloatPartsN *a, FloatPartsN *b, int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); bool sign = a->sign ^ b->sign; - if (likely(ab_mask == float_cmask_normal)) { + if (likely(cmask_is_only_normals(ab_mask))) { + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } a->sign = sign; a->exp -= b->exp + frac_div(a, b); return a; @@ -713,6 +752,10 @@ static FloatPartsN *partsN(div)(FloatPartsN *a, FloatPartsN *b, return parts_pick_nan(a, b, s); } + if ((ab_mask & float_cmask_denormal) && b->cls != float_class_zero) { + float_raise(float_flag_input_denormal_used, s); + } + a->sign = sign; /* Inf / X */ @@ -750,7 +793,10 @@ static FloatPartsN *partsN(modrem)(FloatPartsN *a, FloatPartsN *b, { int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); - if (likely(ab_mask == float_cmask_normal)) { + if (likely(cmask_is_only_normals(ab_mask))) { + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } frac_modrem(a, b, mod_quot); return a; } @@ -771,6 +817,10 @@ static FloatPartsN *partsN(modrem)(FloatPartsN *a, FloatPartsN *b, return a; } + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + /* N % Inf; 0 % N */ g_assert(b->cls == float_class_inf || a->cls == float_class_zero); return a; @@ -800,6 +850,12 @@ static void partsN(sqrt)(FloatPartsN *a, float_status *status, if (unlikely(a->cls != float_class_normal)) { switch (a->cls) { + case float_class_denormal: + if (!a->sign) { + /* -ve denormal will be InvalidOperation */ + float_raise(float_flag_input_denormal_used, status); + } + break; case float_class_snan: case float_class_qnan: parts_return_nan(a, status); @@ -1130,6 +1186,7 @@ static void partsN(round_to_int)(FloatPartsN *a, FloatRoundMode rmode, case float_class_inf: break; case float_class_normal: + case float_class_denormal: if (parts_round_to_int_normal(a, rmode, scale, fmt->frac_size)) { float_raise(float_flag_inexact, s); } @@ -1174,6 +1231,7 @@ static int64_t partsN(float_to_sint)(FloatPartsN *p, FloatRoundMode rmode, return 0; case float_class_normal: + case float_class_denormal: /* TODO: N - 2 is frac_size for rounding; could use input fmt. */ if (parts_round_to_int_normal(p, rmode, scale, N - 2)) { flags = float_flag_inexact; @@ -1241,6 +1299,7 @@ static uint64_t partsN(float_to_uint)(FloatPartsN *p, FloatRoundMode rmode, return 0; case float_class_normal: + case float_class_denormal: /* TODO: N - 2 is frac_size for rounding; could use input fmt. */ if (parts_round_to_int_normal(p, rmode, scale, N - 2)) { flags = float_flag_inexact; @@ -1304,6 +1363,7 @@ static int64_t partsN(float_to_sint_modulo)(FloatPartsN *p, return 0; case float_class_normal: + case float_class_denormal: /* TODO: N - 2 is frac_size for rounding; could use input fmt. */ if (parts_round_to_int_normal(p, rmode, 0, N - 2)) { flags = float_flag_inexact; @@ -1425,6 +1485,9 @@ static FloatPartsN *partsN(minmax)(FloatPartsN *a, FloatPartsN *b, if ((flags & (minmax_isnum | minmax_isnumber)) && !(ab_mask & float_cmask_snan) && (ab_mask & ~float_cmask_qnan)) { + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } return is_nan(a->cls) ? b : a; } @@ -1449,12 +1512,17 @@ static FloatPartsN *partsN(minmax)(FloatPartsN *a, FloatPartsN *b, return parts_pick_nan(a, b, s); } + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + a_exp = a->exp; b_exp = b->exp; - if (unlikely(ab_mask != float_cmask_normal)) { + if (unlikely(!cmask_is_only_normals(ab_mask))) { switch (a->cls) { case float_class_normal: + case float_class_denormal: break; case float_class_inf: a_exp = INT16_MAX; @@ -1467,6 +1535,7 @@ static FloatPartsN *partsN(minmax)(FloatPartsN *a, FloatPartsN *b, } switch (b->cls) { case float_class_normal: + case float_class_denormal: break; case float_class_inf: b_exp = INT16_MAX; @@ -1513,9 +1582,13 @@ static FloatRelation partsN(compare)(FloatPartsN *a, FloatPartsN *b, { int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); - if (likely(ab_mask == float_cmask_normal)) { + if (likely(cmask_is_only_normals(ab_mask))) { FloatRelation cmp; + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + if (a->sign != b->sign) { goto a_sign; } @@ -1541,6 +1614,10 @@ static FloatRelation partsN(compare)(FloatPartsN *a, FloatPartsN *b, return float_relation_unordered; } + if (ab_mask & float_cmask_denormal) { + float_raise(float_flag_input_denormal_used, s); + } + if (ab_mask & float_cmask_zero) { if (ab_mask == float_cmask_zero) { return float_relation_equal; @@ -1580,6 +1657,9 @@ static void partsN(scalbn)(FloatPartsN *a, int n, float_status *s) case float_class_zero: case float_class_inf: break; + case float_class_denormal: + float_raise(float_flag_input_denormal_used, s); + /* fall through */ case float_class_normal: a->exp += MIN(MAX(n, -0x10000), 0x10000); break; @@ -1599,6 +1679,12 @@ static void partsN(log2)(FloatPartsN *a, float_status *s, const FloatFmt *fmt) if (unlikely(a->cls != float_class_normal)) { switch (a->cls) { + case float_class_denormal: + if (!a->sign) { + /* -ve denormal will be InvalidOperation */ + float_raise(float_flag_input_denormal_used, s); + } + break; case float_class_snan: case float_class_qnan: parts_return_nan(a, s); @@ -1615,9 +1701,8 @@ static void partsN(log2)(FloatPartsN *a, float_status *s, const FloatFmt *fmt) } return; default: - break; + g_assert_not_reached(); } - g_assert_not_reached(); } if (unlikely(a->sign)) { goto d_nan; diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 26f3a8dc87..f4fed9bfda 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -404,12 +404,16 @@ float64_gen2(float64 xa, float64 xb, float_status *s, /* * Classify a floating point number. Everything above float_class_qnan * is a NaN so cls >= float_class_qnan is any NaN. + * + * Note that we canonicalize denormals, so most code should treat + * class_normal and class_denormal identically. */ typedef enum __attribute__ ((__packed__)) { float_class_unclassified, float_class_zero, float_class_normal, + float_class_denormal, /* input was a non-squashed denormal */ float_class_inf, float_class_qnan, /* all NaNs from here */ float_class_snan, @@ -420,12 +424,14 @@ typedef enum __attribute__ ((__packed__)) { enum { float_cmask_zero = float_cmask(float_class_zero), float_cmask_normal = float_cmask(float_class_normal), + float_cmask_denormal = float_cmask(float_class_denormal), float_cmask_inf = float_cmask(float_class_inf), float_cmask_qnan = float_cmask(float_class_qnan), float_cmask_snan = float_cmask(float_class_snan), float_cmask_infzero = float_cmask_zero | float_cmask_inf, float_cmask_anynan = float_cmask_qnan | float_cmask_snan, + float_cmask_anynorm = float_cmask_normal | float_cmask_denormal, }; /* Flags for parts_minmax. */ @@ -460,6 +466,20 @@ static inline __attribute__((unused)) bool is_qnan(FloatClass c) } /* + * Return true if the float_cmask has only normals in it + * (including input denormals that were canonicalized) + */ +static inline bool cmask_is_only_normals(int cmask) +{ + return !(cmask & ~float_cmask_anynorm); +} + +static inline bool is_anynorm(FloatClass c) +{ + return float_cmask(c) & float_cmask_anynorm; +} + +/* * Structure holding all of the decomposed parts of a float. * The exponent is unbiased and the fraction is normalized. * @@ -1729,6 +1749,7 @@ static float64 float64r32_round_pack_canonical(FloatParts64 *p, */ switch (p->cls) { case float_class_normal: + case float_class_denormal: if (unlikely(p->exp == 0)) { /* * The result is denormal for float32, but can be represented @@ -1817,6 +1838,7 @@ static floatx80 floatx80_round_pack_canonical(FloatParts128 *p, switch (p->cls) { case float_class_normal: + case float_class_denormal: if (s->floatx80_rounding_precision == floatx80_precision_x) { parts_uncanon_normal(p, s, fmt); frac = p->frac_hi; @@ -2696,6 +2718,9 @@ static void parts_float_to_ahp(FloatParts64 *a, float_status *s) float16_params_ahp.frac_size + 1); break; + case float_class_denormal: + float_raise(float_flag_input_denormal_used, s); + break; case float_class_normal: case float_class_zero: break; @@ -2710,6 +2735,9 @@ static void parts64_float_to_float(FloatParts64 *a, float_status *s) if (is_nan(a->cls)) { parts_return_nan(a, s); } + if (a->cls == float_class_denormal) { + float_raise(float_flag_input_denormal_used, s); + } } static void parts128_float_to_float(FloatParts128 *a, float_status *s) @@ -2717,6 +2745,9 @@ static void parts128_float_to_float(FloatParts128 *a, float_status *s) if (is_nan(a->cls)) { parts_return_nan(a, s); } + if (a->cls == float_class_denormal) { + float_raise(float_flag_input_denormal_used, s); + } } #define parts_float_to_float(P, S) \ @@ -2729,12 +2760,21 @@ static void parts_float_to_float_narrow(FloatParts64 *a, FloatParts128 *b, a->sign = b->sign; a->exp = b->exp; - if (a->cls == float_class_normal) { + switch (a->cls) { + case float_class_denormal: + float_raise(float_flag_input_denormal_used, s); + /* fall through */ + case float_class_normal: frac_truncjam(a, b); - } else if (is_nan(a->cls)) { + break; + case float_class_snan: + case float_class_qnan: /* Discard the low bits of the NaN. */ a->frac = b->frac_hi; parts_return_nan(a, s); + break; + default: + break; } } @@ -2749,6 +2789,9 @@ static void parts_float_to_float_widen(FloatParts128 *a, FloatParts64 *b, if (is_nan(a->cls)) { parts_return_nan(a, s); } + if (a->cls == float_class_denormal) { + float_raise(float_flag_input_denormal_used, s); + } } float32 float16_to_float32(float16 a, bool ieee, float_status *s) @@ -3218,6 +3261,7 @@ static Int128 float128_to_int128_scalbn(float128 a, FloatRoundMode rmode, return int128_zero(); case float_class_normal: + case float_class_denormal: if (parts_round_to_int_normal(&p, rmode, scale, 128 - 2)) { flags = float_flag_inexact; } @@ -3645,6 +3689,7 @@ static Int128 float128_to_uint128_scalbn(float128 a, FloatRoundMode rmode, return int128_zero(); case float_class_normal: + case float_class_denormal: if (parts_round_to_int_normal(&p, rmode, scale, 128 - 2)) { flags = float_flag_inexact; if (p.cls == float_class_zero) { @@ -4386,7 +4431,11 @@ float32_hs_compare(float32 xa, float32 xb, float_status *s, bool is_quiet) goto soft; } - float32_input_flush2(&ua.s, &ub.s, s); + if (unlikely(float32_is_denormal(ua.s) || float32_is_denormal(ub.s))) { + /* We may need to set the input_denormal_used flag */ + goto soft; + } + if (isgreaterequal(ua.h, ub.h)) { if (isgreater(ua.h, ub.h)) { return float_relation_greater; @@ -4436,7 +4485,11 @@ float64_hs_compare(float64 xa, float64 xb, float_status *s, bool is_quiet) goto soft; } - float64_input_flush2(&ua.s, &ub.s, s); + if (unlikely(float64_is_denormal(ua.s) || float64_is_denormal(ub.s))) { + /* We may need to set the input_denormal_used flag */ + goto soft; + } + if (isgreaterequal(ua.h, ub.h)) { if (isgreater(ua.h, ub.h)) { return float_relation_greater; @@ -5231,6 +5284,8 @@ float32 float32_exp2(float32 a, float_status *status) float32_unpack_canonical(&xp, a, status); if (unlikely(xp.cls != float_class_normal)) { switch (xp.cls) { + case float_class_denormal: + break; case float_class_snan: case float_class_qnan: parts_return_nan(&xp, status); @@ -5240,9 +5295,8 @@ float32 float32_exp2(float32 a, float_status *status) case float_class_zero: return float32_one; default: - break; + g_assert_not_reached(); } - g_assert_not_reached(); } float_raise(float_flag_inexact, status); |