diff --git a/fpu/softfloat.c b/fpu/softfloat.c index b3c4104854..0dc769283d 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -572,6 +572,10 @@ typedef struct { .frac_shift = (-F - 1) & 63, \ .round_mask = (1ull << ((-F - 1) & 63)) - 1 +static const FloatFmt float8_e5m2_params = { + FLOAT_PARAMS(5, 2) +}; + static const FloatFmt float16_params = { FLOAT_PARAMS(5, 10) }; @@ -627,6 +631,11 @@ static void unpack_raw64(FloatParts64 *r, const FloatFmt *fmt, uint64_t raw) }; } +static void QEMU_FLATTEN float8_e5m2_unpack_raw(FloatParts64 *p, float8_e5m2 f) +{ + unpack_raw64(p, &float8_e5m2_params, f); +} + static void QEMU_FLATTEN float16_unpack_raw(FloatParts64 *p, float16 f) { unpack_raw64(p, &float16_params, f); @@ -684,6 +693,11 @@ static uint64_t pack_raw64(const FloatParts64 *p, const FloatFmt *fmt) return ret; } +static float8_e5m2 QEMU_FLATTEN float8_e5m2_pack_raw(const FloatParts64 *p) +{ + return pack_raw64(p, &float8_e5m2_params); +} + static float16 QEMU_FLATTEN float16_pack_raw(const FloatParts64 *p) { return make_float16(pack_raw64(p, &float16_params)); @@ -1675,6 +1689,13 @@ static const uint16_t rsqrt_tab[128] = { * Pack/unpack routines with a specific FloatFmt. */ +static void float8_e5m2_unpack_canonical(FloatParts64 *p, float8_e5m2 f, + float_status *s) +{ + float8_e5m2_unpack_raw(p, f); + parts_canonicalize(p, s, &float8_e5m2_params); +} + static void float16a_unpack_canonical(FloatParts64 *p, float16 f, float_status *s, const FloatFmt *params) { @@ -1695,6 +1716,14 @@ static void bfloat16_unpack_canonical(FloatParts64 *p, bfloat16 f, parts_canonicalize(p, s, &bfloat16_params); } +static float8_e5m2 float8_e5m2_round_pack_canonical(FloatParts64 *p, + float_status *s, + bool saturate) +{ + parts_uncanon(p, s, &float8_e5m2_params, saturate); + return float8_e5m2_pack_raw(p); +} + static float16 float16a_round_pack_canonical(FloatParts64 *p, float_status *s, const FloatFmt *params) @@ -2772,6 +2801,35 @@ static void parts_float_to_ahp(FloatParts64 *a, float_status *s) } } +static void parts_float_to_e5m2(FloatParts64 *a, float_status *s, bool saturate) +{ + switch (a->cls) { + case float_class_snan: + case float_class_qnan: + parts_return_nan(a, s); + break; + + case float_class_inf: + /* Per OCP, conversion in SATURATE mode bounds Inf to MAX. */ + if (saturate) { + a->cls = float_class_normal; + a->exp = float8_e5m2_params.exp_max - 1; + a->frac = MAKE_64BIT_MASK(float8_e5m2_params.frac_shift, + float8_e5m2_params.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; + default: + g_assert_not_reached(); + } +} + static void parts64_float_to_float(FloatParts64 *a, float_status *s) { if (is_nan(a->cls)) { @@ -2836,6 +2894,15 @@ static void parts_float_to_float_widen(FloatParts128 *a, FloatParts64 *b, } } +bfloat16 float8_e5m2_to_bfloat16(float8_e5m2 a, float_status *s) +{ + FloatParts64 p; + + float8_e5m2_unpack_canonical(&p, a, s); + parts_float_to_float(&p, s); + return bfloat16_round_pack_canonical(&p, s); +} + float32 float16_to_float32(float16 a, bool ieee, float_status *s) { const FloatFmt *fmt16 = ieee ? &float16_params : &float16_params_ahp; @@ -2856,6 +2923,15 @@ float64 float16_to_float64(float16 a, bool ieee, float_status *s) return float64_round_pack_canonical(&p, s); } +float8_e5m2 float32_to_float8_e5m2(float32 a, bool saturate, float_status *s) +{ + FloatParts64 p; + + float32_unpack_canonical(&p, a, s); + parts_float_to_e5m2(&p, s, saturate); + return float8_e5m2_round_pack_canonical(&p, s, saturate); +} + float16 float32_to_float16(float32 a, bool ieee, float_status *s) { FloatParts64 p; @@ -2923,6 +2999,15 @@ float32 float64_to_float32(float64 a, float_status *s) return float32_round_pack_canonical(&p, s); } +float8_e5m2 bfloat16_to_float8_e5m2(bfloat16 a, bool saturate, float_status *s) +{ + FloatParts64 p; + + bfloat16_unpack_canonical(&p, a, s); + parts_float_to_e5m2(&p, s, saturate); + return float8_e5m2_round_pack_canonical(&p, s, saturate); +} + float32 bfloat16_to_float32(bfloat16 a, float_status *s) { FloatParts64 p; diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h index 8f82fdfc97..be7e2de6e3 100644 --- a/include/fpu/softfloat-types.h +++ b/include/fpu/softfloat-types.h @@ -119,6 +119,11 @@ typedef struct { */ typedef uint16_t bfloat16; +/* + * Open Compute Project (OCP) Microscaling Formats + */ +typedef uint8_t float8_e5m2; + /* * Software IEC/IEEE floating-point underflow tininess-detection mode. */ diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index 69b9041ef0..4385462992 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -189,6 +189,14 @@ float128 int128_to_float128(Int128, float_status *status); float128 uint64_to_float128(uint64_t, float_status *status); float128 uint128_to_float128(Int128, float_status *status); +/*---------------------------------------------------------------------------- +| OCP FP8 conversion routines. +*----------------------------------------------------------------------------*/ + +bfloat16 float8_e5m2_to_bfloat16(float8_e5m2, float_status *status); +float8_e5m2 bfloat16_to_float8_e5m2(bfloat16, bool sat, float_status *status); +float8_e5m2 float32_to_float8_e5m2(float32, bool sat, float_status *status); + /*---------------------------------------------------------------------------- | Software half-precision conversion routines. *----------------------------------------------------------------------------*/