> Am 10.02.2024 um 11:03 schrieb Jakub Jelinek <ja...@redhat.com>:
>
> Hi!
>
> torture/bitint-37.c test FAILed on i686-linux e.g. on
> signed _BitInt(575) + unsigned _BitInt(575) -> signed _BitInt(575)
> __builtin_add_overflow. With 64-bit limbs, we use 4 .UADDC calls in
> the IL, 2 in a loop (which handles the first 8 limbs), then one partial
> limb (we use 63 bits from that) and finally last_ovf case due to the
> mixing of signed vs. unsigned.
> But with 32-bit limbs, we use 5 .UADDC calls in the IL, 2 in a loop (which
> handles the first 16 limbs), then one full limb above that, one partial
> (31 bits) and finally last_ovf case, and for the last_ovf case the code
> computed incorrect idx and so partly did the wrong thing, e.g. overwrote
> the result from the previous .UADDC.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
Ok
Richard
> 2024-02-10 Jakub Jelinek <ja...@redhat.com>
>
> * gimple-lower-bitint.cc (itint_large_huge::lower_addsub_overflow): Fix
> computation of idx for i == 4 of bitint_prec_huge.
>
> --- gcc/gimple-lower-bitint.cc.jj 2024-02-09 16:16:55.335552760 +0100
> +++ gcc/gimple-lower-bitint.cc 2024-02-09 20:41:50.397455671 +0100
> @@ -4031,7 +4031,7 @@ bitint_large_huge::lower_addsub_overflow
> if (kind != bitint_prec_huge)
> idx = size_int (i);
> else if (i >= 2)
> - idx = size_int (fin + (i > 2));
> + idx = size_int (fin + i - 2);
> if (!last_ovf || i < cnt - 1)
> {
> if (type0 != TREE_TYPE (arg0))
>
> Jakub
>