From 94933df0e5c34d1a50fc950553f9c9649cae5320 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 10 May 2018 12:14:21 -0700 Subject: [PATCH] fpu/softfloat: Canonicalize NaN fraction MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Shift the NaN fraction to a canonical position, much like we do for the fraction of normal numbers. This will facilitate manipulation of NaNs within the shared code paths. Tested-by: Alex Bennée Reviewed-by: Alex Bennée Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson --- fpu/softfloat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 0d17027379..607c4a78d5 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -330,10 +330,11 @@ static FloatParts canonicalize(FloatParts part, const FloatFmt *parm, if (part.frac == 0) { part.cls = float_class_inf; } else { + part.frac <<= parm->frac_shift; #ifdef NO_SIGNALING_NANS part.cls = float_class_qnan; #else - int64_t msb = part.frac << (parm->frac_shift + 2); + int64_t msb = part.frac << 2; if ((msb < 0) == status->snan_bit_is_one) { part.cls = float_class_snan; } else { @@ -480,6 +481,7 @@ static FloatParts round_canonical(FloatParts p, float_status *s, case float_class_qnan: case float_class_snan: exp = exp_max; + frac >>= parm->frac_shift; break; default: @@ -503,6 +505,7 @@ static float16 float16_round_pack_canonical(FloatParts p, float_status *s) case float_class_dnan: return float16_default_nan(s); case float_class_msnan: + p.frac >>= float16_params.frac_shift; return float16_maybe_silence_nan(float16_pack_raw(p), s); default: p = round_canonical(p, s, &float16_params); @@ -521,6 +524,7 @@ static float32 float32_round_pack_canonical(FloatParts p, float_status *s) case float_class_dnan: return float32_default_nan(s); case float_class_msnan: + p.frac >>= float32_params.frac_shift; return float32_maybe_silence_nan(float32_pack_raw(p), s); default: p = round_canonical(p, s, &float32_params); @@ -539,6 +543,7 @@ static float64 float64_round_pack_canonical(FloatParts p, float_status *s) case float_class_dnan: return float64_default_nan(s); case float_class_msnan: + p.frac >>= float64_params.frac_shift; return float64_maybe_silence_nan(float64_pack_raw(p), s); default: p = round_canonical(p, s, &float64_params);