From d46975bce10e163b9f10a7f569d3e046114d8580 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 8 Nov 2020 13:01:55 -0800 Subject: [PATCH] softfloat: Move sf_canonicalize to softfloat-parts.c.inc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit At the same time, convert to pointers, rename to parts$N_canonicalize and define a macro for parts_canonicalize using QEMU_GENERIC. Rearrange the cases to recognize float_class_normal as early as possible. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- fpu/softfloat-parts.c.inc | 33 +++++++++++ fpu/softfloat.c | 117 +++++++++++++++++++++++++------------- 2 files changed, 112 insertions(+), 38 deletions(-) diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc index a78d61ea07..25bf99bd0f 100644 --- a/fpu/softfloat-parts.c.inc +++ b/fpu/softfloat-parts.c.inc @@ -100,3 +100,36 @@ static FloatPartsN *partsN(pick_nan_muladd)(FloatPartsN *a, FloatPartsN *b, } return a; } + +/* + * Canonicalize the FloatParts structure. Determine the class, + * unbias the exponent, and normalize the fraction. + */ +static void partsN(canonicalize)(FloatPartsN *p, float_status *status, + const FloatFmt *fmt) +{ + if (unlikely(p->exp == 0)) { + if (likely(frac_eqz(p))) { + p->cls = float_class_zero; + } else if (status->flush_inputs_to_zero) { + float_raise(float_flag_input_denormal, status); + p->cls = float_class_zero; + frac_clear(p); + } else { + int shift = frac_normalize(p); + p->cls = float_class_normal; + p->exp = fmt->frac_shift - fmt->exp_bias - shift + 1; + } + } else if (likely(p->exp < fmt->exp_max) || fmt->arm_althp) { + p->cls = float_class_normal; + p->exp -= fmt->exp_bias; + frac_shl(p, fmt->frac_shift); + p->frac_hi |= DECOMPOSED_IMPLICIT_BIT; + } else if (likely(frac_eqz(p))) { + p->cls = float_class_inf; + } else { + frac_shl(p, fmt->frac_shift); + p->cls = (parts_is_snan_frac(p->frac_hi, status) + ? float_class_snan : float_class_qnan); + } +} diff --git a/fpu/softfloat.c b/fpu/softfloat.c index df004dbe2f..535261db44 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -733,6 +733,14 @@ static FloatParts128 *parts128_pick_nan_muladd(FloatParts128 *a, #define parts_pick_nan_muladd(A, B, C, S, ABM, ABCM) \ PARTS_GENERIC_64_128(pick_nan_muladd, A)(A, B, C, S, ABM, ABCM) +static void parts64_canonicalize(FloatParts64 *p, float_status *status, + const FloatFmt *fmt); +static void parts128_canonicalize(FloatParts128 *p, float_status *status, + const FloatFmt *fmt); + +#define parts_canonicalize(A, S, F) \ + PARTS_GENERIC_64_128(canonicalize, A)(A, S, F) + /* * Helper functions for softfloat-parts.c.inc, per-size operations. */ @@ -759,52 +767,85 @@ static int frac128_cmp(FloatParts128 *a, FloatParts128 *b) #define frac_cmp(A, B) FRAC_GENERIC_64_128(cmp, A)(A, B) +static void frac64_clear(FloatParts64 *a) +{ + a->frac = 0; +} + +static void frac128_clear(FloatParts128 *a) +{ + a->frac_hi = a->frac_lo = 0; +} + +#define frac_clear(A) FRAC_GENERIC_64_128(clear, A)(A) + +static bool frac64_eqz(FloatParts64 *a) +{ + return a->frac == 0; +} + +static bool frac128_eqz(FloatParts128 *a) +{ + return (a->frac_hi | a->frac_lo) == 0; +} + +#define frac_eqz(A) FRAC_GENERIC_64_128(eqz, A)(A) + +static int frac64_normalize(FloatParts64 *a) +{ + if (a->frac) { + int shift = clz64(a->frac); + a->frac <<= shift; + return shift; + } + return 64; +} + +static int frac128_normalize(FloatParts128 *a) +{ + if (a->frac_hi) { + int shl = clz64(a->frac_hi); + if (shl) { + int shr = 64 - shl; + a->frac_hi = (a->frac_hi << shl) | (a->frac_lo >> shr); + a->frac_lo = (a->frac_lo << shl); + } + return shl; + } else if (a->frac_lo) { + int shl = clz64(a->frac_lo); + a->frac_hi = (a->frac_lo << shl); + a->frac_lo = 0; + return shl + 64; + } + return 128; +} + +#define frac_normalize(A) FRAC_GENERIC_64_128(normalize, A)(A) + +static void frac64_shl(FloatParts64 *a, int c) +{ + a->frac <<= c; +} + static void frac128_shl(FloatParts128 *a, int c) { shift128Left(a->frac_hi, a->frac_lo, c, &a->frac_hi, &a->frac_lo); } -#define frac_shl(A, C) frac128_shl(A, C) +#define frac_shl(A, C) FRAC_GENERIC_64_128(shl, A)(A, C) + +static void frac64_shr(FloatParts64 *a, int c) +{ + a->frac >>= c; +} static void frac128_shr(FloatParts128 *a, int c) { shift128Right(a->frac_hi, a->frac_lo, c, &a->frac_hi, &a->frac_lo); } -#define frac_shr(A, C) frac128_shr(A, C) +#define frac_shr(A, C) FRAC_GENERIC_64_128(shr, A)(A, C) -/* Canonicalize EXP and FRAC, setting CLS. */ -static FloatParts64 sf_canonicalize(FloatParts64 part, const FloatFmt *parm, - float_status *status) -{ - if (part.exp == parm->exp_max && !parm->arm_althp) { - if (part.frac == 0) { - part.cls = float_class_inf; - } else { - part.frac <<= parm->frac_shift; - part.cls = (parts_is_snan_frac(part.frac, status) - ? float_class_snan : float_class_qnan); - } - } else if (part.exp == 0) { - if (likely(part.frac == 0)) { - part.cls = float_class_zero; - } else if (status->flush_inputs_to_zero) { - float_raise(float_flag_input_denormal, status); - part.cls = float_class_zero; - part.frac = 0; - } else { - int shift = clz64(part.frac); - part.cls = float_class_normal; - part.exp = parm->frac_shift - parm->exp_bias - shift + 1; - part.frac <<= shift; - } - } else { - part.cls = float_class_normal; - part.exp -= parm->exp_bias; - part.frac = DECOMPOSED_IMPLICIT_BIT + (part.frac << parm->frac_shift); - } - return part; -} /* Round and uncanonicalize a floating-point number by parts. There * are FRAC_SHIFT bits that may require rounding at the bottom of the @@ -984,7 +1025,7 @@ static void float16a_unpack_canonical(FloatParts64 *p, float16 f, float_status *s, const FloatFmt *params) { float16_unpack_raw(p, f); - *p = sf_canonicalize(*p, params, s); + parts_canonicalize(p, s, params); } static void float16_unpack_canonical(FloatParts64 *p, float16 f, @@ -997,7 +1038,7 @@ static void bfloat16_unpack_canonical(FloatParts64 *p, bfloat16 f, float_status *s) { bfloat16_unpack_raw(p, f); - *p = sf_canonicalize(*p, &bfloat16_params, s); + parts_canonicalize(p, s, &bfloat16_params); } static float16 float16a_round_pack_canonical(FloatParts64 *p, @@ -1025,7 +1066,7 @@ static void float32_unpack_canonical(FloatParts64 *p, float32 f, float_status *s) { float32_unpack_raw(p, f); - *p = sf_canonicalize(*p, &float32_params, s); + parts_canonicalize(p, s, &float32_params); } static float32 float32_round_pack_canonical(FloatParts64 *p, @@ -1039,7 +1080,7 @@ static void float64_unpack_canonical(FloatParts64 *p, float64 f, float_status *s) { float64_unpack_raw(p, f); - *p = sf_canonicalize(*p, &float64_params, s); + parts_canonicalize(p, s, &float64_params); } static float64 float64_round_pack_canonical(FloatParts64 *p,