diff options
Diffstat (limited to 'fpu/softfloat.c')
| -rw-r--r-- | fpu/softfloat.c | 94 |
1 files changed, 89 insertions, 5 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 9132d7a0b0..4610738ab1 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 : round_mask; + 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 : round_mask; + 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 : rnd_mask; + 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 +3551,9 @@ 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; + break; default: abort(); break; @@ -3536,8 +3564,10 @@ 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 +3585,13 @@ 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) { @@ -6793,6 +6830,35 @@ uint32_t float128_to_uint32_round_to_zero(float128 a, float_status *status) } /*---------------------------------------------------------------------------- +| Returns the result of converting the quadruple-precision floating-point value +| `a' to the 32-bit unsigned integer format. The conversion is +| performed according to the IEC/IEEE Standard for Binary Floating-Point +| Arithmetic---which means in particular that the conversion is rounded +| according to the current rounding mode. If `a' is a NaN, the largest +| positive integer is returned. If the conversion overflows, the +| largest unsigned integer is returned. If 'a' is negative, the value is +| rounded and zero is returned; negative values that do not round to zero +| will raise the inexact exception. +*----------------------------------------------------------------------------*/ + +uint32_t float128_to_uint32(float128 a, float_status *status) +{ + uint64_t v; + uint32_t res; + int old_exc_flags = get_float_exception_flags(status); + + v = float128_to_uint64(a, status); + if (v > 0xffffffff) { + res = 0xffffffff; + } else { + return v; + } + set_float_exception_flags(old_exc_flags, status); + float_raise(float_flag_invalid, status); + return res; +} + +/*---------------------------------------------------------------------------- | Returns the result of converting the quadruple-precision floating-point | value `a' to the single-precision floating-point format. The conversion | is performed according to the IEC/IEEE Standard for Binary Floating-Point @@ -6958,6 +7024,15 @@ float128 float128_round_to_int(float128 a, float_status *status) add128(z.high, z.low, 0, roundBitsMask, &z.high, &z.low); } break; + case float_round_to_odd: + /* + * Note that if lastBitMask == 0, the last bit is the lsb + * of high, and roundBitsMask == -1. + */ + if ((lastBitMask ? z.low & lastBitMask : z.high & 1) == 0) { + add128(z.high, z.low, 0, roundBitsMask, &z.high, &z.low); + } + break; default: abort(); } @@ -6969,7 +7044,7 @@ float128 float128_round_to_int(float128 a, float_status *status) status->float_exception_flags |= float_flag_inexact; aSign = extractFloat128Sign( a ); switch (status->float_rounding_mode) { - case float_round_nearest_even: + case float_round_nearest_even: if ( ( aExp == 0x3FFE ) && ( extractFloat128Frac0( a ) | extractFloat128Frac1( a ) ) @@ -6982,14 +7057,17 @@ float128 float128_round_to_int(float128 a, float_status *status) return packFloat128(aSign, 0x3FFF, 0, 0); } break; - case float_round_down: + case float_round_down: return aSign ? packFloat128( 1, 0x3FFF, 0, 0 ) : packFloat128( 0, 0, 0, 0 ); - case float_round_up: + case float_round_up: return aSign ? packFloat128( 1, 0, 0, 0 ) : packFloat128( 0, 0x3FFF, 0, 0 ); + + case float_round_to_odd: + return packFloat128(aSign, 0x3FFF, 0, 0); } return packFloat128( aSign, 0, 0, 0 ); } @@ -7022,6 +7100,12 @@ float128 float128_round_to_int(float128 a, float_status *status) z.high += roundBitsMask; } break; + case float_round_to_odd: + if ((z.high & lastBitMask) == 0) { + z.high |= (a.low != 0); + z.high += roundBitsMask; + } + break; default: abort(); } |