llvm-project

39c454af - [TTI] getScalingFactorCost should return InstructionCost::getInvalid() instead of -1. (#129802)

[TTI] getScalingFactorCost should return InstructionCost::getInvalid() instead of -1. (#129802) Historically this function return an int with negative values meaning invalid. It was migrated to InstructionCost in 43ace8b5ce07a, but the code was not updated to return invalid cost instead of -1. In that commit, the caller in LSR was updated to assert that the cost is valid instead of positive. We should return invalid instead of a negative value so LSR will assert if the cost isn't valid.