On Tue, Jun 02, 2020 at 12:50:25PM +0100, Richard Sandiford wrote: > This might not be the best time to bring this up :-) but it seems > odd to be asking the target for the induction variable type here. > I got the impression that the hook was returning DImode, whereas > the PowerPC instructions only looked at the low 8 bits of the length.
It's the top(!) 8 bits of the register actually (the other 56 bits are "do not care" bits). > If so, forcing a naturally 32-bit IV to DImode would insert extra > sign/zero extensions, even though the input to the length intrinsics > would have been happy with the 32-bit IV. It's a shift left always. All bits beyond the 8 drop out. Thanks for the great reviews Richard, much appreciated! Segher
