Lanai

const Lanai = extern struct {
    r: [32]Gpr,

    pub const Gpr = u32;

    pub inline fn current() Lanai {
        var ctx: Lanai = undefined;
        asm volatile (
            \\ st %%r0, 0[%%r9]
            \\ st %%r1, 4[%%r9]
            \\ st %%r2, 8[%%r9]
            \\ st %%r3, 12[%%r9]
            \\ st %%r4, 16[%%r9]
            \\ st %%r5, 20[%%r9]
            \\ st %%r6, 24[%%r9]
            \\ st %%r7, 28[%%r9]
            \\ st %%r8, 32[%%r9]
            \\ st %%r9, 36[%%r9]
            \\ st %%r10, 40[%%r9]
            \\ st %%r11, 44[%%r9]
            \\ st %%r12, 48[%%r9]
            \\ st %%r13, 52[%%r9]
            \\ st %%r14, 56[%%r9]
            \\ st %%r15, 60[%%r9]
            \\ st %%r16, 64[%%r9]
            \\ st %%r17, 68[%%r9]
            \\ st %%r18, 72[%%r9]
            \\ st %%r19, 76[%%r9]
            \\ st %%r20, 80[%%r9]
            \\ st %%r21, 84[%%r9]
            \\ st %%r22, 88[%%r9]
            \\ st %%r23, 92[%%r9]
            \\ st %%r24, 96[%%r9]
            \\ st %%r25, 100[%%r9]
            \\ st %%r26, 104[%%r9]
            \\ st %%r27, 108[%%r9]
            \\ st %%r28, 112[%%r9]
            \\ st %%r29, 116[%%r9]
            \\ st %%r30, 120[%%r9]
            \\ st %%r31, 124[%%r9]
            :
            : [ctx] "{r9}" (&ctx),
            : .{ .memory = true });
        return ctx;
    }

    pub fn getFp(ctx: *const Lanai) usize {
        return ctx.r[5];
    }
    pub fn getPc(ctx: *const Lanai) usize {
        return ctx.r[2];
    }

    pub fn dwarfRegisterBytes(ctx: *Lanai, register_num: u16) DwarfRegisterError![]u8 {
        switch (register_num) {
            0...31 => return @ptrCast(&ctx.r[register_num]),

            else => return error.InvalidRegister,
        }
    }
}