diff mbox series

[v5,05/28] fpu/softfloat: Canonicalize NaN fraction

Message ID 20180514221219.7091-6-richard.henderson@linaro.org
State Superseded
Headers show
Series softfloat patch roundup | expand

Commit Message

Richard Henderson May 14, 2018, 10:11 p.m. UTC
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.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 fpu/softfloat.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

-- 
2.17.0

Comments

Peter Maydell May 15, 2018, 10:50 a.m. UTC | #1
On 14 May 2018 at 23:11, Richard Henderson <richard.henderson@linaro.org> wrote:
> 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.

>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Reviewed-by: Peter Maydell <peter.maydell@linaro.org>


thanks
-- PMM
Alex Bennée May 15, 2018, 11:44 a.m. UTC | #2
Richard Henderson <richard.henderson@linaro.org> writes:

> 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.

>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


> ---

>  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);



--
Alex Bennée
diff mbox series

Patch

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);