Commit e8c9e651 authored by Jason Ekstrand's avatar Jason Ekstrand

intel/fs: Use a pure vertical stride for large register strides

Register strides higher than 4 are uncommon but they can happen.  For
instance, if you have a 64-bit extract_u8 operation, we turn that into
UB -> UQ MOV with a source stride of 8.  Our previous calculation would
try to generate a stride of <32;8,8>:ub which is invalid because the
maximum horizontal stride is 4.  To solve this problem, we instead use a
stride of <8;1,0>.  As noted in the comment, this does not work as a
destination but that's ok as very few things actually generate that
stride.
Reviewed-by: Samuel Iglesias Gonsálvez's avatarSamuel Iglesias Gonsálvez <siglesias@igalia.com>
Cc: mesa-stable@lists.freedesktop.org
parent bd24f489
......@@ -90,9 +90,19 @@ brw_reg_from_fs_reg(const struct gen_device_info *devinfo, fs_inst *inst,
* different execution size when the number of components
* written to each destination GRF is not the same.
*/
const unsigned width = MIN2(reg_width, phys_width);
brw_reg = brw_vecn_reg(width, brw_file_from_reg(reg), reg->nr, 0);
brw_reg = stride(brw_reg, width * reg->stride, width, reg->stride);
if (reg->stride > 4) {
/* For registers with an exceptionally large stride, we use a
* width of 1 and only use the vertical stride. This only works
* for sources since destinations require hstride == 1.
*/
assert(reg != &inst->dst);
brw_reg = brw_vec1_reg(brw_file_from_reg(reg), reg->nr, 0);
brw_reg = stride(brw_reg, reg->stride, 1, 0);
} else {
const unsigned width = MIN2(reg_width, phys_width);
brw_reg = brw_vecn_reg(width, brw_file_from_reg(reg), reg->nr, 0);
brw_reg = stride(brw_reg, width * reg->stride, width, reg->stride);
}
if (devinfo->gen == 7 && !devinfo->is_haswell) {
/* From the IvyBridge PRM (EU Changes by Processor Generation, page 13):
......
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