llvm-project

e20b9047 - [PseudoProbe] Make probe discriminator compatible with dwarf base discriminator (#94506)

[PseudoProbe] Make probe discriminator compatible with dwarf base discriminator (#94506) It's useful if the probe-based build can consume a dwarf based profile(e.g. the profile transition), before there is a conflict for the discriminator, this change tries to mitigate the issue by encoding the dwarf base discriminator into the probe discriminator. As the num of probe id(num of basic block and calls) starts from 1, there are some unused space. We try to reuse some bit of the probe id. The new encode rule is: - Use a bit to [28:28] to indicate whether dwarf base discriminator is encoded.(fortunately we can borrow this bit from the `PseudoProbeType`) - If the bit is set, use [15:3] for probe id, [18:16] for dwarf base discriminator. Otherwise, still use [18:3] for probe id. Note that these doesn't affect the original probe id capacity, we still prioritize probe id encoding, i.e. the base discriminator is not encoded when probe id is bigger than [15:3]. Then adjust `getBaseDiscriminatorFromDiscriminator` to use the base discriminator from the probe discriminator.