llvm-project

8d920725 - [RISCV] Use FMV.D for moving GPRPairs on RV32_Zdinx (#169556)

[RISCV] Use FMV.D for moving GPRPairs on RV32_Zdinx (#169556) This is noted by the specification, and should save a dynamic instruction. Code size should be no worse than before, as the pairs of moves can usually be turned into two 16-bit moves, but `fmv.d` is always a 32-bit instruction. LLVM can look through a `FSGNJ_D_IN32X`, in `RISCVInstrInfo::isCopyInstrImpl` which helps copy propagation.