This patch is CC'd to stable, but CTS regressions bisected to it:
https://bugs.freedesktop.org/show_bug.cgi?id=103626
Please do not merge to stable until the bug is addressed.
Jason Ekstrand <ja...@jlekstrand.net> writes:
> Some hardware (CHV, BXT) have special restrictions on register regions
> when doing integer multiplication. We want to respect those when we
> lower to DxW multiplication.
>
> Cc: mesa-sta...@lists.freedesktop.org
> ---
> src/intel/compiler/brw_fs.cpp | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
> index 56455e9..1c4351b 100644
> --- a/src/intel/compiler/brw_fs.cpp
> +++ b/src/intel/compiler/brw_fs.cpp
> @@ -3482,18 +3482,20 @@ fs_visitor::lower_integer_multiplication()
>
> bool needs_mov = false;
> fs_reg orig_dst = inst->dst;
> + fs_reg low = inst->dst;
> if (orig_dst.is_null() || orig_dst.file == MRF ||
> regions_overlap(inst->dst, inst->size_written,
> inst->src[0], inst->size_read(0)) ||
> regions_overlap(inst->dst, inst->size_written,
> inst->src[1], inst->size_read(1))) {
> needs_mov = true;
> - inst->dst = fs_reg(VGRF, alloc.allocate(dispatch_width / 8),
> - inst->dst.type);
> + low.nr = alloc.allocate(regs_written(inst));
> + low.offset = low.offset % REG_SIZE;
> }
> - fs_reg low = inst->dst;
> - fs_reg high(VGRF, alloc.allocate(dispatch_width / 8),
> - inst->dst.type);
> +
> + fs_reg high = inst->dst;
> + high.nr = alloc.allocate(regs_written(inst));
> + high.offset = high.offset % REG_SIZE;
>
> if (devinfo->gen >= 7) {
> if (inst->src[1].file == IMM) {
> @@ -3514,13 +3516,13 @@ fs_visitor::lower_integer_multiplication()
> inst->src[1]);
> }
>
> - ibld.ADD(subscript(inst->dst, BRW_REGISTER_TYPE_UW, 1),
> + ibld.ADD(subscript(low, BRW_REGISTER_TYPE_UW, 1),
> subscript(low, BRW_REGISTER_TYPE_UW, 1),
> subscript(high, BRW_REGISTER_TYPE_UW, 0));
>
> if (needs_mov || inst->conditional_mod) {
> set_condmod(inst->conditional_mod,
> - ibld.MOV(orig_dst, inst->dst));
> + ibld.MOV(orig_dst, low));
> }
> }
>
> --
> 2.5.0.400.gff86faf
>
> _______________________________________________
> mesa-stable mailing list
> mesa-sta...@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-stable
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