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authorRichard Henderson <richard.henderson@linaro.org>2018-05-10 12:14:21 -0700
committerRichard Henderson <richard.henderson@linaro.org>2018-05-17 15:24:19 -0700
commit94933df0e5c34d1a50fc950553f9c9649cae5320 (patch)
treef0a4621841e810d1922d1b2dc2379f43102f7730
parent0664335a6eb65d684918dd3f1a7f0a3d5b92cbe1 (diff)
downloadqemu-94933df0e5c34d1a50fc950553f9c9649cae5320.zip
fpu/softfloat: Canonicalize NaN fraction
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 <alex.bennee@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
-rw-r--r--fpu/softfloat.c7
1 files changed, 6 insertions, 1 deletions
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);