Re: [PATCH] intXshr, intXshl: return error on shift count out of range

David Rowley <dgrowleyml(at)gmail(dot)com> writes:
> Have you actually tested this on RISC-V? Can you share the results of:
> SELECT 1::bigint << 255, 1::bigint << 63;
> Does it actually crash?

I tried this on the gcc compile farm's cfarm95 (said to be
a Banana Pi BPI-F3 with Spacemit(R) X60 chip; runs Debian trixie).
I see no crash and results consistent with the low-six-bits rule:

regression=# SELECT 1::bigint << 255, 1::bigint << 63;
?column? | ?column?
----------------------+----------------------
-9223372036854775808 | -9223372036854775808
(1 row)

regression=# SELECT 1::bigint << 64, 1::bigint << (-1);
?column? | ?column?
----------+----------------------
1 | -9223372036854775808
(1 row)

I rather imagine you can make it crash if you use ASAN configured to
dump core on whatever behavior it considers undefined ... but I
reject the notion that we should let ASAN dictate our choices here.

regards, tom lane