On 14/11/2019 15:30, Kwok Cheung Yeung wrote:
GCN 5 has commonly-used global memory instructions that specify the
address as [SGPR address] + [VGPR offset] + [constant offset], and we
often want the VGPR offset to be zero, so v0 is currently reserved for
that purpose.
However, v1 contains [0, 1, 2..., 63], and as we only use the first lane
of the VGPR for the offset (the instructions actually work on vectors of
addresses, but we only employ them in single-lane mode for all memory
accesses except for explicit scatter-gather instructions), v1 can be
used in place of v0, freeing v0 for other purposes.
Okay for trunk?
OK.
Andrew
