llvm-project

38aac86a - [TableGen] Speed up inferMatchingSuperRegClass. NFC. (#133060)

[TableGen] Speed up inferMatchingSuperRegClass. NFC. (#133060) SubToSuperRegs was a DenseMap of std::vectors, where the vectors typically had size 1. Switching to a vector of pairs avoids the overhead of allocating tiny vectors. I measured a 1.14x speed-up building AMDGPUGenRegisterInfo.inc with this patch.