Both x87 and m68k need the low parts of the quotient for their remainder operations. Arrange for floatx80_modrem to track those bits and return them via a pointer.
The architectures using float32_rem and float64_rem do not appear to need this information, so the *_rem interface is left unchanged and the information returned only from floatx80_modrem. The logic used to determine the low 7 bits of the quotient for m68k (target/m68k/fpu_helper.c:make_quotient) appears completely bogus (it looks at the result of converting the remainder to integer, the quotient having been discarded by that point); this patch does not change that, but the m68k maintainers may wish to do so. Signed-off-by: Joseph Myers <jos...@codesourcery.com> --- fpu/softfloat.c | 23 ++++++++++++++++++----- include/fpu/softfloat.h | 3 ++- 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 423a815196..c3c3f382af 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -5684,10 +5684,11 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status) | `a' with respect to the corresponding value `b'. The operation is performed | 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. +| the quotient toward zero instead. '*quotient' is set to the low 64 bits of +| the absolute value of the integer quotient. *----------------------------------------------------------------------------*/ -floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, +floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, uint64_t *quotient, float_status *status) { bool aSign, zSign; @@ -5695,6 +5696,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, 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); @@ -5749,7 +5751,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, shift128Right( aSig0, 0, 1, &aSig0, &aSig1 ); expDiff = 0; } - q = ( bSig <= aSig0 ); + *quotient = q = ( bSig <= aSig0 ); if ( q ) aSig0 -= bSig; expDiff -= 64; while ( 0 < expDiff ) { @@ -5759,6 +5761,8 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, sub128( aSig0, aSig1, term0, term1, &aSig0, &aSig1 ); shortShift128Left( aSig0, aSig1, 62, &aSig0, &aSig1 ); expDiff -= 62; + *quotient <<= 62; + *quotient += q; } expDiff += 64; if ( 0 < expDiff ) { @@ -5772,6 +5776,12 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, ++q; sub128( aSig0, aSig1, term0, term1, &aSig0, &aSig1 ); } + if (expDiff < 64) { + *quotient <<= expDiff; + } else { + *quotient = 0; + } + *quotient += q; } else { term1 = 0; @@ -5786,6 +5796,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, aSig0 = alternateASig0; aSig1 = alternateASig1; zSign = ! zSign; + ++*quotient; } } return @@ -5802,7 +5813,8 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) { - return floatx80_modrem(a, b, false, status); + uint64_t quotient; + return floatx80_modrem(a, b, false, "ient, status); } /*---------------------------------------------------------------------------- @@ -5813,7 +5825,8 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) floatx80 floatx80_mod(floatx80 a, floatx80 b, float_status *status) { - return floatx80_modrem(a, b, true, status); + uint64_t quotient; + return floatx80_modrem(a, b, true, "ient, status); } /*---------------------------------------------------------------------------- diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index bff6934d09..ff4e2605b1 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -687,7 +687,8 @@ floatx80 floatx80_add(floatx80, floatx80, float_status *status); floatx80 floatx80_sub(floatx80, floatx80, float_status *status); floatx80 floatx80_mul(floatx80, floatx80, float_status *status); floatx80 floatx80_div(floatx80, floatx80, float_status *status); -floatx80 floatx80_modrem(floatx80, floatx80, bool, float_status *status); +floatx80 floatx80_modrem(floatx80, floatx80, bool, uint64_t *, + float_status *status); floatx80 floatx80_mod(floatx80, floatx80, float_status *status); floatx80 floatx80_rem(floatx80, floatx80, float_status *status); floatx80 floatx80_sqrt(floatx80, float_status *status); -- 2.17.1 -- Joseph S. Myers jos...@codesourcery.com