diff options
Diffstat (limited to 'fpu/softfloat.c')
| -rw-r--r-- | fpu/softfloat.c | 87 |
1 files changed, 71 insertions, 16 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 5e9746c287..79be4f5840 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -5697,22 +5697,27 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status) /*---------------------------------------------------------------------------- | Returns the remainder of the extended double-precision floating-point value | `a' with respect to the corresponding value `b'. The operation is performed -| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic. +| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic, +| if 'mod' is false; if 'mod' is true, return the remainder based on truncating +| the quotient toward zero instead. '*quotient' is set to the low 64 bits of +| the absolute value of the integer quotient. *----------------------------------------------------------------------------*/ -floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) +floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, uint64_t *quotient, + float_status *status) { bool aSign, zSign; - int32_t aExp, bExp, expDiff; + int32_t aExp, bExp, expDiff, aExpOrig; uint64_t aSig0, aSig1, bSig; uint64_t q, term0, term1, alternateASig0, alternateASig1; + *quotient = 0; if (floatx80_invalid_encoding(a) || floatx80_invalid_encoding(b)) { float_raise(float_flag_invalid, status); return floatx80_default_nan(status); } aSig0 = extractFloatx80Frac( a ); - aExp = extractFloatx80Exp( a ); + aExpOrig = aExp = extractFloatx80Exp( a ); aSign = extractFloatx80Sign( a ); bSig = extractFloatx80Frac( b ); bExp = extractFloatx80Exp( b ); @@ -5727,6 +5732,13 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) if ((uint64_t)(bSig << 1)) { return propagateFloatx80NaN(a, b, status); } + if (aExp == 0 && aSig0 >> 63) { + /* + * Pseudo-denormal argument must be returned in normalized + * form. + */ + return packFloatx80(aSign, 1, aSig0); + } return a; } if ( bExp == 0 ) { @@ -5738,19 +5750,27 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) normalizeFloatx80Subnormal( bSig, &bExp, &bSig ); } if ( aExp == 0 ) { - if ( (uint64_t) ( aSig0<<1 ) == 0 ) return a; + if ( aSig0 == 0 ) return a; normalizeFloatx80Subnormal( aSig0, &aExp, &aSig0 ); } - bSig |= UINT64_C(0x8000000000000000); zSign = aSign; expDiff = aExp - bExp; aSig1 = 0; if ( expDiff < 0 ) { - if ( expDiff < -1 ) return a; + if ( mod || expDiff < -1 ) { + if (aExp == 1 && aExpOrig == 0) { + /* + * Pseudo-denormal argument must be returned in + * normalized form. + */ + return packFloatx80(aSign, aExp, aSig0); + } + return a; + } shift128Right( aSig0, 0, 1, &aSig0, &aSig1 ); expDiff = 0; } - q = ( bSig <= aSig0 ); + *quotient = q = ( bSig <= aSig0 ); if ( q ) aSig0 -= bSig; expDiff -= 64; while ( 0 < expDiff ) { @@ -5760,6 +5780,8 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) sub128( aSig0, aSig1, term0, term1, &aSig0, &aSig1 ); shortShift128Left( aSig0, aSig1, 62, &aSig0, &aSig1 ); expDiff -= 62; + *quotient <<= 62; + *quotient += q; } expDiff += 64; if ( 0 < expDiff ) { @@ -5773,19 +5795,28 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) ++q; sub128( aSig0, aSig1, term0, term1, &aSig0, &aSig1 ); } + if (expDiff < 64) { + *quotient <<= expDiff; + } else { + *quotient = 0; + } + *quotient += q; } else { term1 = 0; term0 = bSig; } - sub128( term0, term1, aSig0, aSig1, &alternateASig0, &alternateASig1 ); - if ( lt128( alternateASig0, alternateASig1, aSig0, aSig1 ) - || ( eq128( alternateASig0, alternateASig1, aSig0, aSig1 ) - && ( q & 1 ) ) - ) { - aSig0 = alternateASig0; - aSig1 = alternateASig1; - zSign = ! zSign; + if (!mod) { + sub128( term0, term1, aSig0, aSig1, &alternateASig0, &alternateASig1 ); + if ( lt128( alternateASig0, alternateASig1, aSig0, aSig1 ) + || ( eq128( alternateASig0, alternateASig1, aSig0, aSig1 ) + && ( q & 1 ) ) + ) { + aSig0 = alternateASig0; + aSig1 = alternateASig1; + zSign = ! zSign; + ++*quotient; + } } return normalizeRoundAndPackFloatx80( @@ -5794,6 +5825,30 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) } /*---------------------------------------------------------------------------- +| Returns the remainder of the extended double-precision floating-point value +| `a' with respect to the corresponding value `b'. The operation is performed +| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) +{ + uint64_t quotient; + return floatx80_modrem(a, b, false, "ient, status); +} + +/*---------------------------------------------------------------------------- +| Returns the remainder of the extended double-precision floating-point value +| `a' with respect to the corresponding value `b', with the quotient truncated +| toward zero. +*----------------------------------------------------------------------------*/ + +floatx80 floatx80_mod(floatx80 a, floatx80 b, float_status *status) +{ + uint64_t quotient; + return floatx80_modrem(a, b, true, "ient, status); +} + +/*---------------------------------------------------------------------------- | Returns the square root of the extended double-precision floating-point | value `a'. The operation is performed according to the IEC/IEEE Standard | for Binary Floating-Point Arithmetic. |