| Message ID | 20210508014802.892561-51-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Convert floatx80 and float128 to FloatParts | expand |
On 08.05.21 03:47, Richard Henderson wrote: > Rename to parts$N_minmax. Combine 3 bool arguments to a bitmask, > return a tri-state value to indicate nan vs unchanged operand. > Introduce ftype_minmax functions as a common optimization point. > Fold bfloat16 expansions into the same macro as the other types. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > fpu/softfloat.c | 216 ++++++++++++++++---------------------- > fpu/softfloat-parts.c.inc | 69 ++++++++++++ > 2 files changed, 158 insertions(+), 127 deletions(-) > > diff --git a/fpu/softfloat.c b/fpu/softfloat.c > index 586ea5d67a..4c04e88a3a 100644 > --- a/fpu/softfloat.c > +++ b/fpu/softfloat.c > @@ -482,6 +482,15 @@ enum { > float_cmask_anynan = float_cmask_qnan | float_cmask_snan, > }; > > +/* Flags for parts_minmax. */ > +enum { > + /* Set for minimum; clear for maximum. */ > + minmax_ismin = 1, > + /* Set for the IEEE 754-2008 minNum() and maxNum() operations. */ > + minmax_isnum = 2, > + /* Set for the IEEE 754-2008 minNumMag() and minNumMag() operations. */ > + minmax_ismag = 4 | minmax_isnum > +}; > > /* Simple helpers for checking if, or what kind of, NaN we have */ > static inline __attribute__((unused)) bool is_nan(FloatClass c) > @@ -864,6 +873,14 @@ static void parts128_uint_to_float(FloatParts128 *p, uint64_t a, > #define parts_uint_to_float(P, I, Z, S) \ > PARTS_GENERIC_64_128(uint_to_float, P)(P, I, Z, S) > > +static int parts64_minmax(FloatParts64 *a, FloatParts64 *b, > + float_status *s, int flags, const FloatFmt *fmt); > +static int parts128_minmax(FloatParts128 *a, FloatParts128 *b, > + float_status *s, int flags, const FloatFmt *fmt); > + > +#define parts_minmax(A, B, S, Z, F) \ > + PARTS_GENERIC_64_128(minmax, A)(A, B, S, Z, F) > + > /* > * Helper functions for softfloat-parts.c.inc, per-size operations. > */ > @@ -3257,145 +3274,90 @@ float128 uint64_to_float128(uint64_t a, float_status *status) > return float128_round_pack_canonical(&p, status); > } > > -/* Float Min/Max */ > -/* min() and max() functions. These can't be implemented as > - * 'compare and pick one input' because that would mishandle > - * NaNs and +0 vs -0. > - * > - * minnum() and maxnum() functions. These are similar to the min() > - * and max() functions but if one of the arguments is a QNaN and > - * the other is numerical then the numerical argument is returned. > - * SNaNs will get quietened before being returned. > - * minnum() and maxnum correspond to the IEEE 754-2008 minNum() > - * and maxNum() operations. min() and max() are the typical min/max > - * semantics provided by many CPUs which predate that specification. > - * > - * minnummag() and maxnummag() functions correspond to minNumMag() > - * and minNumMag() from the IEEE-754 2008. > +/* > + * Minimum and maximum > */ > -static FloatParts64 minmax_floats(FloatParts64 a, FloatParts64 b, bool ismin, > - bool ieee, bool ismag, float_status *s) > + > +static float16 float16_minmax(float16 a, float16 b, float_status *s, int flags) > { > - if (unlikely(is_nan(a.cls) || is_nan(b.cls))) { > - if (ieee) { > - /* Takes two floating-point values `a' and `b', one of > - * which is a NaN, and returns the appropriate NaN > - * result. If either `a' or `b' is a signaling NaN, > - * the invalid exception is raised. > - */ > - if (is_snan(a.cls) || is_snan(b.cls)) { > - return *parts_pick_nan(&a, &b, s); > - } else if (is_nan(a.cls) && !is_nan(b.cls)) { > - return b; > - } else if (is_nan(b.cls) && !is_nan(a.cls)) { > - return a; > - } > - } > - return *parts_pick_nan(&a, &b, s); > - } else { > - int a_exp, b_exp; > + FloatParts64 pa, pb; > + int which; > > - switch (a.cls) { > - case float_class_normal: > - a_exp = a.exp; > - break; > - case float_class_inf: > - a_exp = INT_MAX; > - break; > - case float_class_zero: > - a_exp = INT_MIN; > - break; > - default: > - g_assert_not_reached(); > - break; > - } > - switch (b.cls) { > - case float_class_normal: > - b_exp = b.exp; > - break; > - case float_class_inf: > - b_exp = INT_MAX; > - break; > - case float_class_zero: > - b_exp = INT_MIN; > - break; > - default: > - g_assert_not_reached(); > - break; > - } > - > - if (ismag && (a_exp != b_exp || a.frac != b.frac)) { > - bool a_less = a_exp < b_exp; > - if (a_exp == b_exp) { > - a_less = a.frac < b.frac; > - } > - return a_less ^ ismin ? b : a; > - } > - > - if (a.sign == b.sign) { > - bool a_less = a_exp < b_exp; > - if (a_exp == b_exp) { > - a_less = a.frac < b.frac; > - } > - return a.sign ^ a_less ^ ismin ? b : a; > - } else { > - return a.sign ^ ismin ? b : a; > - } > + float16_unpack_canonical(&pa, a, s); > + float16_unpack_canonical(&pb, b, s); > + which = parts_minmax(&pa, &pb, s, flags, &float16_params); > + if (unlikely(which < 0)) { > + /* Some sort of nan, need to repack default and silenced nans. */ > + return float16_round_pack_canonical(&pa, s); > } > + return which ? b : a; > } > > -#define MINMAX(sz, name, ismin, isiee, ismag) \ > -float ## sz float ## sz ## _ ## name(float ## sz a, float ## sz b, \ > - float_status *s) \ > -{ \ > - FloatParts64 pa, pb, pr; \ > - float ## sz ## _unpack_canonical(&pa, a, s); \ > - float ## sz ## _unpack_canonical(&pb, b, s); \ > - pr = minmax_floats(pa, pb, ismin, isiee, ismag, s); \ > - return float ## sz ## _round_pack_canonical(&pr, s); \ > +static bfloat16 bfloat16_minmax(bfloat16 a, bfloat16 b, > + float_status *s, int flags) > +{ > + FloatParts64 pa, pb; > + int which; > + > + bfloat16_unpack_canonical(&pa, a, s); > + bfloat16_unpack_canonical(&pb, b, s); > + which = parts_minmax(&pa, &pb, s, flags, &float16_params); > + if (unlikely(which < 0)) { > + /* Some sort of nan, need to repack default and silenced nans. */ > + return bfloat16_round_pack_canonical(&pa, s); > + } > + return which ? b : a; > } > > -MINMAX(16, min, true, false, false) > -MINMAX(16, minnum, true, true, false) > -MINMAX(16, minnummag, true, true, true) > -MINMAX(16, max, false, false, false) > -MINMAX(16, maxnum, false, true, false) > -MINMAX(16, maxnummag, false, true, true) > +static float32 float32_minmax(float32 a, float32 b, float_status *s, int flags) > +{ > + FloatParts64 pa, pb; > + int which; > > -MINMAX(32, min, true, false, false) > -MINMAX(32, minnum, true, true, false) > -MINMAX(32, minnummag, true, true, true) > -MINMAX(32, max, false, false, false) > -MINMAX(32, maxnum, false, true, false) > -MINMAX(32, maxnummag, false, true, true) > - > -MINMAX(64, min, true, false, false) > -MINMAX(64, minnum, true, true, false) > -MINMAX(64, minnummag, true, true, true) > -MINMAX(64, max, false, false, false) > -MINMAX(64, maxnum, false, true, false) > -MINMAX(64, maxnummag, false, true, true) > - > -#undef MINMAX > - > -#define BF16_MINMAX(name, ismin, isiee, ismag) \ > -bfloat16 bfloat16_ ## name(bfloat16 a, bfloat16 b, float_status *s) \ > -{ \ > - FloatParts64 pa, pb, pr; \ > - bfloat16_unpack_canonical(&pa, a, s); \ > - bfloat16_unpack_canonical(&pb, b, s); \ > - pr = minmax_floats(pa, pb, ismin, isiee, ismag, s); \ > - return bfloat16_round_pack_canonical(&pr, s); \ > + float32_unpack_canonical(&pa, a, s); > + float32_unpack_canonical(&pb, b, s); > + which = parts_minmax(&pa, &pb, s, flags, &float32_params); > + if (unlikely(which < 0)) { > + /* Some sort of nan, need to repack default and silenced nans. */ > + return float32_round_pack_canonical(&pa, s); > + } > + return which ? b : a; > } > > -BF16_MINMAX(min, true, false, false) > -BF16_MINMAX(minnum, true, true, false) > -BF16_MINMAX(minnummag, true, true, true) > -BF16_MINMAX(max, false, false, false) > -BF16_MINMAX(maxnum, false, true, false) > -BF16_MINMAX(maxnummag, false, true, true) > +static float64 float64_minmax(float64 a, float64 b, float_status *s, int flags) > +{ > + FloatParts64 pa, pb; > + int which; > > -#undef BF16_MINMAX > + float64_unpack_canonical(&pa, a, s); > + float64_unpack_canonical(&pb, b, s); > + which = parts_minmax(&pa, &pb, s, flags, &float64_params); > + if (unlikely(which < 0)) { > + /* Some sort of nan, need to repack default and silenced nans. */ > + return float64_round_pack_canonical(&pa, s); > + } > + return which ? b : a; > +} > + > +#define MINMAX_1(type, name, flags) \ > + type type##_##name(type a, type b, float_status *s) \ > + { return type##_minmax(a, b, s, flags); } > + > +#define MINMAX_2(type) \ > + MINMAX_1(type, max, 0) \ > + MINMAX_1(type, maxnum, minmax_isnum) \ > + MINMAX_1(type, maxnummag, minmax_ismag) \ > + MINMAX_1(type, min, minmax_ismin) \ > + MINMAX_1(type, minnum, minmax_ismin | minmax_isnum) \ > + MINMAX_1(type, minnummag, minmax_ismin | minmax_ismag) > + > +MINMAX_2(float16) > +MINMAX_2(bfloat16) > +MINMAX_2(float32) > +MINMAX_2(float64) > + > +#undef MINMAX_1 > +#undef MINMAX_2 > > /* Floating point compare */ > static FloatRelation compare_floats(FloatParts64 a, FloatParts64 b, bool is_quiet, > diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc > index f3c4f8c8d2..4d91ef0d32 100644 > --- a/fpu/softfloat-parts.c.inc > +++ b/fpu/softfloat-parts.c.inc > @@ -936,3 +936,72 @@ static void partsN(uint_to_float)(FloatPartsN *p, uint64_t a, > p->frac_hi = a << shift; > } > } > + > +/* > + * Float min/max. > + * > + * Return -1 to return the chosen nan in *a; > + * return 0 to use the a input unchanged; 1 to use the b input unchanged. > + */ > +static int partsN(minmax)(FloatPartsN *a, FloatPartsN *b, > + float_status *s, int flags, const FloatFmt *fmt) > +{ > + int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); > + int a_exp, b_exp; > + bool a_less; > + > + if (unlikely(ab_mask & float_cmask_anynan)) { > + /* > + * For minnum/maxnum, if one operand is a QNaN, and the other > + * operand is numerical, then return numerical argument. > + */ > + if ((flags & minmax_isnum) > + && !(ab_mask & float_cmask_snan) > + && (ab_mask & ~float_cmask_qnan)) { > + return is_nan(a->cls); > + } > + *a = *parts_pick_nan(a, b, s); > + return -1; > + } > + > + a_exp = a->exp; > + b_exp = b->exp; > + > + if (unlikely(ab_mask != float_cmask_normal)) { > + switch (a->cls) { > + case float_class_normal: > + break; > + case float_class_inf: > + a_exp = INT_MAX; > + break; > + case float_class_zero: > + a_exp = INT_MIN; > + break; > + default: > + g_assert_not_reached(); > + break; > + } > + switch (b->cls) { > + case float_class_normal: > + break; > + case float_class_inf: > + b_exp = INT_MAX; > + break; > + case float_class_zero: > + b_exp = INT_MIN; > + break; > + default: > + g_assert_not_reached(); > + break; > + } > + } > + > + if (a->sign != b->sign && !(flags & minmax_ismag)) { > + a_less = a->sign; > + } else if (a_exp != b_exp) { > + a_less = a_exp < b_exp; > + } else { > + a_less = frac_cmp(a, b) < 0; > + } > + return a_less ^ !!(flags & minmax_ismin); > +} This patch introduces two issues: 1. Comparing two negative numbers is broken. We have to invert the a_less result. 2. The check "flags & minmax_ismag" is broken because "minmax_ismag = 4 | minmax_isnum" and it, therefore, also triggers for "flags = minmax_isnum" The following seems to make it work in my tests: diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc index 1bc8db4cf1..d5a73dac00 100644 --- a/fpu/softfloat-parts.c.inc +++ b/fpu/softfloat-parts.c.inc @@ -1273,6 +1273,9 @@ static int partsN(minmax)(FloatPartsN *a, FloatPartsN *b, } else { a_less = frac_cmp(a, b) < 0; } + if (a->sign && b->sign && !(flags & minmax_ismag)) { + a_less = !a_less; + } return a_less ^ !!(flags & minmax_ismin); } diff --git a/fpu/softfloat.c b/fpu/softfloat.c index bfe5a6b975..649e8c6592 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -435,7 +435,7 @@ enum { /* Set for the IEEE 754-2008 minNum() and maxNum() operations. */ minmax_isnum = 2, /* Set for the IEEE 754-2008 minNumMag() and minNumMag() operations. */ - minmax_ismag = 4 | minmax_isnum + minmax_ismag = 4, }; /* Simple helpers for checking if, or what kind of, NaN we have */ @@ -3916,10 +3916,10 @@ static float128 float128_minmax(float128 a, float128 b, float_status *s, #define MINMAX_2(type) \ MINMAX_1(type, max, 0) \ MINMAX_1(type, maxnum, minmax_isnum) \ - MINMAX_1(type, maxnummag, minmax_ismag) \ + MINMAX_1(type, maxnummag, minmax_isnum | minmax_ismag) \ MINMAX_1(type, min, minmax_ismin) \ MINMAX_1(type, minnum, minmax_ismin | minmax_isnum) \ - MINMAX_1(type, minnummag, minmax_ismin | minmax_ismag) + MINMAX_1(type, minnummag, minmax_ismin | minmax_isnum | minmax_ismag) MINMAX_2(float16) MINMAX_2(bfloat16) -- Thanks, David / dhildenb
On 5/17/21 8:14 AM, David Hildenbrand wrote: > This patch introduces two issues: > > 1. Comparing two negative numbers is broken. We have to > invert the a_less result. > > 2. The check "flags & minmax_ismag" is broken because > "minmax_ismag = 4 | minmax_isnum" and it, therefore, > also triggers for "flags = minmax_isnum" Thanks. I guess I should assume from this that these tests are not enabled, and I should fix that as well. r~
diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 586ea5d67a..4c04e88a3a 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -482,6 +482,15 @@ enum { float_cmask_anynan = float_cmask_qnan | float_cmask_snan, }; +/* Flags for parts_minmax. */ +enum { + /* Set for minimum; clear for maximum. */ + minmax_ismin = 1, + /* Set for the IEEE 754-2008 minNum() and maxNum() operations. */ + minmax_isnum = 2, + /* Set for the IEEE 754-2008 minNumMag() and minNumMag() operations. */ + minmax_ismag = 4 | minmax_isnum +}; /* Simple helpers for checking if, or what kind of, NaN we have */ static inline __attribute__((unused)) bool is_nan(FloatClass c) @@ -864,6 +873,14 @@ static void parts128_uint_to_float(FloatParts128 *p, uint64_t a, #define parts_uint_to_float(P, I, Z, S) \ PARTS_GENERIC_64_128(uint_to_float, P)(P, I, Z, S) +static int parts64_minmax(FloatParts64 *a, FloatParts64 *b, + float_status *s, int flags, const FloatFmt *fmt); +static int parts128_minmax(FloatParts128 *a, FloatParts128 *b, + float_status *s, int flags, const FloatFmt *fmt); + +#define parts_minmax(A, B, S, Z, F) \ + PARTS_GENERIC_64_128(minmax, A)(A, B, S, Z, F) + /* * Helper functions for softfloat-parts.c.inc, per-size operations. */ @@ -3257,145 +3274,90 @@ float128 uint64_to_float128(uint64_t a, float_status *status) return float128_round_pack_canonical(&p, status); } -/* Float Min/Max */ -/* min() and max() functions. These can't be implemented as - * 'compare and pick one input' because that would mishandle - * NaNs and +0 vs -0. - * - * minnum() and maxnum() functions. These are similar to the min() - * and max() functions but if one of the arguments is a QNaN and - * the other is numerical then the numerical argument is returned. - * SNaNs will get quietened before being returned. - * minnum() and maxnum correspond to the IEEE 754-2008 minNum() - * and maxNum() operations. min() and max() are the typical min/max - * semantics provided by many CPUs which predate that specification. - * - * minnummag() and maxnummag() functions correspond to minNumMag() - * and minNumMag() from the IEEE-754 2008. +/* + * Minimum and maximum */ -static FloatParts64 minmax_floats(FloatParts64 a, FloatParts64 b, bool ismin, - bool ieee, bool ismag, float_status *s) + +static float16 float16_minmax(float16 a, float16 b, float_status *s, int flags) { - if (unlikely(is_nan(a.cls) || is_nan(b.cls))) { - if (ieee) { - /* Takes two floating-point values `a' and `b', one of - * which is a NaN, and returns the appropriate NaN - * result. If either `a' or `b' is a signaling NaN, - * the invalid exception is raised. - */ - if (is_snan(a.cls) || is_snan(b.cls)) { - return *parts_pick_nan(&a, &b, s); - } else if (is_nan(a.cls) && !is_nan(b.cls)) { - return b; - } else if (is_nan(b.cls) && !is_nan(a.cls)) { - return a; - } - } - return *parts_pick_nan(&a, &b, s); - } else { - int a_exp, b_exp; + FloatParts64 pa, pb; + int which; - switch (a.cls) { - case float_class_normal: - a_exp = a.exp; - break; - case float_class_inf: - a_exp = INT_MAX; - break; - case float_class_zero: - a_exp = INT_MIN; - break; - default: - g_assert_not_reached(); - break; - } - switch (b.cls) { - case float_class_normal: - b_exp = b.exp; - break; - case float_class_inf: - b_exp = INT_MAX; - break; - case float_class_zero: - b_exp = INT_MIN; - break; - default: - g_assert_not_reached(); - break; - } - - if (ismag && (a_exp != b_exp || a.frac != b.frac)) { - bool a_less = a_exp < b_exp; - if (a_exp == b_exp) { - a_less = a.frac < b.frac; - } - return a_less ^ ismin ? b : a; - } - - if (a.sign == b.sign) { - bool a_less = a_exp < b_exp; - if (a_exp == b_exp) { - a_less = a.frac < b.frac; - } - return a.sign ^ a_less ^ ismin ? b : a; - } else { - return a.sign ^ ismin ? b : a; - } + float16_unpack_canonical(&pa, a, s); + float16_unpack_canonical(&pb, b, s); + which = parts_minmax(&pa, &pb, s, flags, &float16_params); + if (unlikely(which < 0)) { + /* Some sort of nan, need to repack default and silenced nans. */ + return float16_round_pack_canonical(&pa, s); } + return which ? b : a; } -#define MINMAX(sz, name, ismin, isiee, ismag) \ -float ## sz float ## sz ## _ ## name(float ## sz a, float ## sz b, \ - float_status *s) \ -{ \ - FloatParts64 pa, pb, pr; \ - float ## sz ## _unpack_canonical(&pa, a, s); \ - float ## sz ## _unpack_canonical(&pb, b, s); \ - pr = minmax_floats(pa, pb, ismin, isiee, ismag, s); \ - return float ## sz ## _round_pack_canonical(&pr, s); \ +static bfloat16 bfloat16_minmax(bfloat16 a, bfloat16 b, + float_status *s, int flags) +{ + FloatParts64 pa, pb; + int which; + + bfloat16_unpack_canonical(&pa, a, s); + bfloat16_unpack_canonical(&pb, b, s); + which = parts_minmax(&pa, &pb, s, flags, &float16_params); + if (unlikely(which < 0)) { + /* Some sort of nan, need to repack default and silenced nans. */ + return bfloat16_round_pack_canonical(&pa, s); + } + return which ? b : a; } -MINMAX(16, min, true, false, false) -MINMAX(16, minnum, true, true, false) -MINMAX(16, minnummag, true, true, true) -MINMAX(16, max, false, false, false) -MINMAX(16, maxnum, false, true, false) -MINMAX(16, maxnummag, false, true, true) +static float32 float32_minmax(float32 a, float32 b, float_status *s, int flags) +{ + FloatParts64 pa, pb; + int which; -MINMAX(32, min, true, false, false) -MINMAX(32, minnum, true, true, false) -MINMAX(32, minnummag, true, true, true) -MINMAX(32, max, false, false, false) -MINMAX(32, maxnum, false, true, false) -MINMAX(32, maxnummag, false, true, true) - -MINMAX(64, min, true, false, false) -MINMAX(64, minnum, true, true, false) -MINMAX(64, minnummag, true, true, true) -MINMAX(64, max, false, false, false) -MINMAX(64, maxnum, false, true, false) -MINMAX(64, maxnummag, false, true, true) - -#undef MINMAX - -#define BF16_MINMAX(name, ismin, isiee, ismag) \ -bfloat16 bfloat16_ ## name(bfloat16 a, bfloat16 b, float_status *s) \ -{ \ - FloatParts64 pa, pb, pr; \ - bfloat16_unpack_canonical(&pa, a, s); \ - bfloat16_unpack_canonical(&pb, b, s); \ - pr = minmax_floats(pa, pb, ismin, isiee, ismag, s); \ - return bfloat16_round_pack_canonical(&pr, s); \ + float32_unpack_canonical(&pa, a, s); + float32_unpack_canonical(&pb, b, s); + which = parts_minmax(&pa, &pb, s, flags, &float32_params); + if (unlikely(which < 0)) { + /* Some sort of nan, need to repack default and silenced nans. */ + return float32_round_pack_canonical(&pa, s); + } + return which ? b : a; } -BF16_MINMAX(min, true, false, false) -BF16_MINMAX(minnum, true, true, false) -BF16_MINMAX(minnummag, true, true, true) -BF16_MINMAX(max, false, false, false) -BF16_MINMAX(maxnum, false, true, false) -BF16_MINMAX(maxnummag, false, true, true) +static float64 float64_minmax(float64 a, float64 b, float_status *s, int flags) +{ + FloatParts64 pa, pb; + int which; -#undef BF16_MINMAX + float64_unpack_canonical(&pa, a, s); + float64_unpack_canonical(&pb, b, s); + which = parts_minmax(&pa, &pb, s, flags, &float64_params); + if (unlikely(which < 0)) { + /* Some sort of nan, need to repack default and silenced nans. */ + return float64_round_pack_canonical(&pa, s); + } + return which ? b : a; +} + +#define MINMAX_1(type, name, flags) \ + type type##_##name(type a, type b, float_status *s) \ + { return type##_minmax(a, b, s, flags); } + +#define MINMAX_2(type) \ + MINMAX_1(type, max, 0) \ + MINMAX_1(type, maxnum, minmax_isnum) \ + MINMAX_1(type, maxnummag, minmax_ismag) \ + MINMAX_1(type, min, minmax_ismin) \ + MINMAX_1(type, minnum, minmax_ismin | minmax_isnum) \ + MINMAX_1(type, minnummag, minmax_ismin | minmax_ismag) + +MINMAX_2(float16) +MINMAX_2(bfloat16) +MINMAX_2(float32) +MINMAX_2(float64) + +#undef MINMAX_1 +#undef MINMAX_2 /* Floating point compare */ static FloatRelation compare_floats(FloatParts64 a, FloatParts64 b, bool is_quiet, diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc index f3c4f8c8d2..4d91ef0d32 100644 --- a/fpu/softfloat-parts.c.inc +++ b/fpu/softfloat-parts.c.inc @@ -936,3 +936,72 @@ static void partsN(uint_to_float)(FloatPartsN *p, uint64_t a, p->frac_hi = a << shift; } } + +/* + * Float min/max. + * + * Return -1 to return the chosen nan in *a; + * return 0 to use the a input unchanged; 1 to use the b input unchanged. + */ +static int partsN(minmax)(FloatPartsN *a, FloatPartsN *b, + float_status *s, int flags, const FloatFmt *fmt) +{ + int ab_mask = float_cmask(a->cls) | float_cmask(b->cls); + int a_exp, b_exp; + bool a_less; + + if (unlikely(ab_mask & float_cmask_anynan)) { + /* + * For minnum/maxnum, if one operand is a QNaN, and the other + * operand is numerical, then return numerical argument. + */ + if ((flags & minmax_isnum) + && !(ab_mask & float_cmask_snan) + && (ab_mask & ~float_cmask_qnan)) { + return is_nan(a->cls); + } + *a = *parts_pick_nan(a, b, s); + return -1; + } + + a_exp = a->exp; + b_exp = b->exp; + + if (unlikely(ab_mask != float_cmask_normal)) { + switch (a->cls) { + case float_class_normal: + break; + case float_class_inf: + a_exp = INT_MAX; + break; + case float_class_zero: + a_exp = INT_MIN; + break; + default: + g_assert_not_reached(); + break; + } + switch (b->cls) { + case float_class_normal: + break; + case float_class_inf: + b_exp = INT_MAX; + break; + case float_class_zero: + b_exp = INT_MIN; + break; + default: + g_assert_not_reached(); + break; + } + } + + if (a->sign != b->sign && !(flags & minmax_ismag)) { + a_less = a->sign; + } else if (a_exp != b_exp) { + a_less = a_exp < b_exp; + } else { + a_less = frac_cmp(a, b) < 0; + } + return a_less ^ !!(flags & minmax_ismin); +}
Rename to parts$N_minmax. Combine 3 bool arguments to a bitmask, return a tri-state value to indicate nan vs unchanged operand. Introduce ftype_minmax functions as a common optimization point. Fold bfloat16 expansions into the same macro as the other types. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- fpu/softfloat.c | 216 ++++++++++++++++---------------------- fpu/softfloat-parts.c.inc | 69 ++++++++++++ 2 files changed, 158 insertions(+), 127 deletions(-) -- 2.25.1