Previously this was only supported for roundAndPackFloat64.
Include support in round_canonical, round_to_int, roundAndPackFloat32,
roundAndPackInt32, roundAndPackInt64, roundAndPackUint64.
This does not include any of the floatx80 routines, as we
do not have users for that rounding mode there.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
David, if you could test this vs your s390 patches, vs real s390
hardware, that would be lovely.
r~
---
fpu/softfloat.c | 40 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 38 insertions(+), 2 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 9132d7a0b0..325c6e4e79 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -696,6 +696,7 @@ static FloatParts sf_canonicalize(FloatParts part, const
FloatFmt *parm,
static FloatParts round_canonical(FloatParts p, float_status *s,
const FloatFmt *parm)
{
+ const uint64_t frac_lsb = parm->frac_lsb;
const uint64_t frac_lsbm1 = parm->frac_lsbm1;
const uint64_t round_mask = parm->round_mask;
const uint64_t roundeven_mask = parm->roundeven_mask;
@@ -731,6 +732,10 @@ static FloatParts round_canonical(FloatParts p,
float_status *s,
inc = p.sign ? round_mask : 0;
overflow_norm = !p.sign;
break;
+ case float_round_to_odd:
+ overflow_norm = true;
+ inc = frac & frac_lsb ? 0 : frac_lsbm1;
+ break;
default:
g_assert_not_reached();
}
@@ -778,9 +783,14 @@ static FloatParts round_canonical(FloatParts p,
float_status *s,
shift64RightJamming(frac, 1 - exp, &frac);
if (frac & round_mask) {
/* Need to recompute round-to-even. */
- if (s->float_rounding_mode == float_round_nearest_even) {
+ switch (s->float_rounding_mode) {
+ case float_round_nearest_even:
inc = ((frac & roundeven_mask) != frac_lsbm1
? frac_lsbm1 : 0);
+ break;
+ case float_round_to_odd:
+ inc = frac & frac_lsb ? 0 : frac_lsbm1;
+ break;
}
flags |= float_flag_inexact;
frac += inc;
@@ -1988,6 +1998,9 @@ static FloatParts round_to_int(FloatParts a, int rmode,
case float_round_down:
one = a.sign;
break;
+ case float_round_to_odd:
+ one = true;
+ break;
default:
g_assert_not_reached();
}
@@ -2021,6 +2034,9 @@ static FloatParts round_to_int(FloatParts a, int rmode,
case float_round_down:
inc = a.sign ? rnd_mask : 0;
break;
+ case float_round_to_odd:
+ inc = a.frac & frac_lsb ? 0 : frac_lsbm1;
+ break;
default:
g_assert_not_reached();
}
@@ -3314,6 +3330,9 @@ static int32_t roundAndPackInt32(flag zSign, uint64_t
absZ, float_status *status
case float_round_down:
roundIncrement = zSign ? 0x7f : 0;
break;
+ case float_round_to_odd:
+ roundIncrement = absZ & 0x80 ? 0 : 0x7f;
+ break;
default:
abort();
}
@@ -3368,6 +3387,9 @@ static int64_t roundAndPackInt64(flag zSign, uint64_t
absZ0, uint64_t absZ1,
case float_round_down:
increment = zSign && absZ1;
break;
+ case float_round_to_odd:
+ increment = !(absZ0 & 1) && absZ1;
+ break;
default:
abort();
}
@@ -3424,6 +3446,9 @@ static int64_t roundAndPackUint64(flag zSign, uint64_t
absZ0,
case float_round_down:
increment = zSign && absZ1;
break;
+ case float_round_to_odd:
+ increment = !(absZ0 & 1) && absZ1;
+ break;
default:
abort();
}
@@ -3526,6 +3551,8 @@ static float32 roundAndPackFloat32(flag zSign, int zExp,
uint32_t zSig,
case float_round_down:
roundIncrement = zSign ? 0x7f : 0;
break;
+ case float_round_to_odd:
+ roundIncrement = zSig & 0x80 ? 0 : 0x7f;
default:
abort();
break;
@@ -3536,8 +3563,10 @@ static float32 roundAndPackFloat32(flag zSign, int zExp,
uint32_t zSig,
|| ( ( zExp == 0xFD )
&& ( (int32_t) ( zSig + roundIncrement ) < 0 ) )
) {
+ bool overflow_to_inf = roundingMode != float_round_to_odd &&
+ roundIncrement != 0;
float_raise(float_flag_overflow | float_flag_inexact, status);
- return packFloat32( zSign, 0xFF, - ( roundIncrement == 0 ));
+ return packFloat32(zSign, 0xFF, -!overflow_to_inf);
}
if ( zExp < 0 ) {
if (status->flush_to_zero) {
@@ -3555,6 +3584,13 @@ static float32 roundAndPackFloat32(flag zSign, int zExp,
uint32_t zSig,
if (isTiny && roundBits) {
float_raise(float_flag_underflow, status);
}
+ if (roundingMode == float_round_to_odd) {
+ /*
+ * For round-to-odd case, the roundIncrement depends on
+ * zSig which just changed.
+ */
+ roundIncrement = zSig & 0x80 ? 0 : 0x7f;
+ }
}
}
if (roundBits) {
--
2.17.2
