On 2/2/2026 9:42 PM, Li, Pan2 wrote:
The middle-end pass NULL_TREE in previous, and then skip the adjust_stmt_cost
step which has count the cost of vr2gpr.
After Richard introduced more like slp_node with its vectype for recording the
cost, the adjust_stmt_cost will be hit and plus the cost of vr2gpr now.
And then fail to vectorize due to cost value changes of vr2gpr from 0 to 2.
That means we need to reconsider how to pass the cost value from the command
line eventually.
If we need to add more options for cost, shall we consider to introduce a
config file for all possible costs values?
It may look like a json file which contains sorts of cost num, instead of add
it separately. (may have minor discuss with kito last summer I bet.)
I would suggest deferring the json file issue and instead just add a new
param for this specific issue. We may want to open the json discussion
as part of the gcc-17 development process, but not for this bug -- using
a json file like that is a bigger discussion.
I think all that is consistent when the discussion from the patchwork
meeting.
Jeff
