This commit provides the OCP FP4 E2M1 to OCP FP8 E4M3 covert operation for the Zvfofp4min extension.
Signed-off-by: Max Chou <[email protected]> --- fpu/softfloat.c | 37 +++++++++++++++++++++++++++++++++++-- include/fpu/softfloat.h | 2 ++ 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 0c7f052ec0..30ba6d6c09 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -562,6 +562,11 @@ typedef struct { .frac_shift = (-F - 1) & 63, \ .round_mask = (1ull << ((-F - 1) & 63)) - 1 +static const FloatFmt float4_e2m1_params = { + FLOAT_PARAMS(2, 1), + .ocpfp = true +}; + static const FloatFmt float8_e4m3_params = { FLOAT_PARAMS(4, 3), .ocpfp = true @@ -638,6 +643,11 @@ static void unpack_raw64(FloatParts64 *r, const FloatFmt *fmt, uint64_t raw) }; } +static void QEMU_FLATTEN float4_e2m1_unpack_raw(FloatParts64 *p, float4_e2m1 f) +{ + unpack_raw64(p, &float4_e2m1_params, f); +} + static void QEMU_FLATTEN float8_e4m3_unpack_raw(FloatParts64 *p, float8_e4m3 f) { unpack_raw64(p, &float8_e4m3_params, f); @@ -1664,7 +1674,11 @@ static bool ocpfp64_is_normal(const FloatParts64 *a, const FloatFmt *fmt, } if (fmt->ocpfp) { - if (fmt->exp_size == 4 && fmt->frac_size == 3) { + if (fmt->exp_size == 2 && fmt->frac_size == 1) { + if (input.exp <= fmt->exp_max) { + return true; + } + } else if (fmt->exp_size == 4 && fmt->frac_size == 3) { /* * The OCP E4M3 format uses only two bit patterns for NaN (a * single mantissa-exponent bit pattern with the sign bit) in @@ -1704,7 +1718,11 @@ static bool ocpfp128_is_normal(const FloatParts128 *a, const FloatFmt *fmt, } if (fmt->ocpfp) { - if (fmt->exp_size == 4 && fmt->frac_size == 3) { + if (fmt->exp_size == 2 && fmt->frac_size == 1) { + if (input.exp <= fmt->exp_max) { + return true; + } + } else if (fmt->exp_size == 4 && fmt->frac_size == 3) { /* * The OCP E4M3 format uses only two bit patterns for NaN (a * single mantissa-exponent bit pattern with the sign bit) in @@ -1791,6 +1809,13 @@ static const uint16_t rsqrt_tab[128] = { * Pack/unpack routines with a specific FloatFmt. */ +static void float4_e2m1_unpack_canonical(FloatParts64 *p, float4_e2m1 f, + float_status *s) +{ + float4_e2m1_unpack_raw(p, f); + parts_canonicalize(p, s, &float4_e2m1_params); +} + static void float8_e4m3_unpack_canonical(FloatParts64 *p, float8_e4m3 f, float_status *s) { @@ -2999,6 +3024,14 @@ static void parts_float_to_float_widen(FloatParts128 *a, FloatParts64 *b, } } +float8_e4m3 float4_e2m1_to_float8_e4m3(float4_e2m1 a, float_status *s) +{ + FloatParts64 p; + + float4_e2m1_unpack_canonical(&p, a, s); + parts_float_to_ofp8(&p, s, &float8_e4m3_params); + return float8_e4m3_round_pack_canonical(&p, s, &float8_e4m3_params); +} bfloat16 float8_e4m3_to_bfloat16(float8_e4m3 a, float_status *s) { diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index 13b882bc67..b199a029b0 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -200,6 +200,8 @@ float8_e5m2 bfloat16_to_float8_e5m2(bfloat16, bool saturate, float_status *statu float8_e4m3 float32_to_float8_e4m3(float32, bool saturate, float_status *status); float8_e5m2 float32_to_float8_e5m2(float32, bool saturate, float_status *status); +float8_e4m3 float4_e2m1_to_float8_e4m3(float4_e2m1, float_status *status); + /*---------------------------------------------------------------------------- | Software OCP FP operations. *----------------------------------------------------------------------------*/ -- 2.43.7
