[Bug c++/110304] __builtin_adcs missing and jakub you miss the point of builtin_adcb

[unlvsur at live dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110304

--- Comment #18 from cqwrteur <unlvsur at live dot com> ---
Would you mind if I clarified a few points regarding your query? I'm referring
to implementing "sub borrow" with sub_overflow, as demonstrated in the code
snippet at https://godbolt.org/z/ev3TfeTvd , correct?

Additionally, I'd like to inquire about the possibility of enabling the
compiler to comprehend the "carry + set value" pattern. For instance, in the
given example:
carry = sub_carry(false, a, b, c);
unsigned v { carry ? 38u : 0u };

To clarify, the intention is to utilize the carry flag for subtraction
operations where a register subtracts itself and then performs a bitwise AND
operation with a specified value.
carry = sub_carry(false, a, b, c);
unsigned v;
carry = sub_carry(carry, v, v, v);
v &= 38u;