This change implements support for the `cr` and `cf` register constraints (which allocate a RVC GPR or RVC FPR respectively), and the `N` modifier (which prints the raw encoding of a register rather than the name). The intention behind these additions is to make it easier to use inline assembly when assembling raw instructions that are not supported by the compiler, for instance when experimenting with new instructions or when supporting proprietary extensions outside the toolchain. These implement part of my proposal in riscv-non-isa/riscv-c-api-doc#92 As part of the implementation, I felt there was not enough coverage of inline assembly and the "in X" floating-point extensions, so I have added more regression tests around these configurations.
18 KiB
18 KiB