[Mesa-dev] [PATCH 03/23] i965/fs: Fix copy propagation of load payload for double operands

[Francisco Jerez]

Samuel Iglesias Gonsálvez <siglesias at igalia.com> writes:

> From: Iago Toral Quiroga <itoral at igalia.com>
>
> Specifically, consider the size of the data type of the operand to compute
> the number of registers written.
> ---
>  src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
> index 9147e60..abc68c8 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
> @@ -775,7 +775,7 @@ fs_visitor::opt_copy_propagate_local(void *copy_prop_ctx, bblock_t *block,
>           int offset = 0;
>           for (int i = 0; i < inst->sources; i++) {
>              int effective_width = i < inst->header_size ? 8 : inst->exec_size;
> -            int regs_written = effective_width / 8;
> +            int regs_written = effective_width / 8 * type_sz(inst->src[i].type) / 4;

Please use 'effective_width * type_sz(...) / REG_SIZE' instead, they are
not necessarily equivalent due to rounding and only the latter is
correct when they aren't.  (The existing code still looks broken when
the result is not an exact multiple of REG_SIZE but that probably
belongs in a separate patch...)

With that fixed:
Reviewed-by: Francisco Jerez <currojerez at riseup.net>

>              if (inst->src[i].file == VGRF) {
>                 acp_entry *entry = ralloc(copy_prop_ctx, acp_entry);
>                 entry->dst = inst->dst;
> -- 
> 2.5.0
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 212 bytes
Desc: not available
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20160510/da55f278/attachment.sig>