diff --git a/backends/cxxrtl/runtime/cxxrtl/cxxrtl.h b/backends/cxxrtl/runtime/cxxrtl/cxxrtl.h index bd4affc30..2d5451287 100644 --- a/backends/cxxrtl/runtime/cxxrtl/cxxrtl.h +++ b/backends/cxxrtl/runtime/cxxrtl/cxxrtl.h @@ -508,12 +508,13 @@ struct value : public expr_base<value<Bits>> { size_t count = 0; for (size_t n = 0; n < chunks; n++) { chunk::type x = data[chunks - 1 - n]; - if (x == 0) { - count += (n == 0 ? Bits % chunk::bits : chunk::bits); - } else { - // This loop implements the find first set idiom as recognized by LLVM. - for (; x != 0; count++) + // First add to `count` as if the chunk is zero + count += (n == 0 ? Bits % chunk::bits : chunk::bits); + // If the chunk isn't zero, correct the `count` value and return + if (x != 0) { + for (; x != 0; count--) x >>= 1; + break; } } return count; @@ -582,8 +583,9 @@ struct value : public expr_base<value<Bits>> { value<Bits> dividend = *this; if (dividend.ucmp(divisor)) return {/*quotient=*/value<Bits>{0u}, /*remainder=*/dividend}; - uint32_t divisor_shift = dividend.ctlz() - divisor.ctlz(); - divisor = divisor.shl(value<Bits>{divisor_shift}); + int64_t divisor_shift = divisor.ctlz() - dividend.ctlz(); + assert(divisor_shift >= 0); + divisor = divisor.shl(value<Bits>{(chunk::type) divisor_shift}); for (size_t step = 0; step <= divisor_shift; step++) { quotient = quotient.shl(value<Bits>{1u}); if (!dividend.ucmp(divisor)) { @@ -795,7 +797,10 @@ std::ostream &operator<<(std::ostream &os, const value_formatted<Bits> &vf) buf += '0'; while (!val.is_zero()) { value<Bits> quotient, remainder; - std::tie(quotient, remainder) = val.udivmod(value<Bits>{10u}); + if (Bits >= 4) + std::tie(quotient, remainder) = val.udivmod(value<Bits>{10u}); + else + std::tie(quotient, remainder) = std::make_pair(value<Bits>{0u}, val); buf += '0' + remainder.template trunc<(Bits > 4 ? 4 : Bits)>().val().template get<uint8_t>(); val = quotient; }