On 4/17/20 2:24 PM, Richard Henderson wrote: > On 4/17/20 9:22 AM, Stephen Long wrote: >> +#define DO_RADDHN(N, M, SH) ((N + M + (1 << (SH - 1))) >> SH) > > This formula will overflow. See DO_RSHR -- with some added parenthesis, we > could actually reuse that macro.
My bad. While it does overflow, all of these operations are truncating not saturating, and moreover truncate to halfesize bits. Therefore overflow doesn't matter. r~