Hi Michael, On 2017-12-13 01:01:19 +0000, Andres Freund wrote: > Provide overflow safe integer math inline functions.
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=dangomushi&dt=2017-12-13%2018%3A00%3A18 which seems half like a compiler bug to me. But either way, we gotta work around it. I suspect the reason configure test doesn't sufficiently detect this here is because it's testing the function with constant arguments. Could you perhaps test whether replacing PGAC_C_BUILTIN_OP_OVERFLOW's body with something like result PG_INT64_TYPE a; PG_INT64_TYPE b; PG_INT64_TYPE result; __builtin_mul_overflow(*(volatile PG_INT64_TYPE*) &a, *(volatile PG_INT64_TYPE*) &b, &result); makes it fail? I'd rather not test this via the buildfarm, given that dangomushi isn't the most frequently running / fastest animal. - Andres
