RISC-V two lables on the same line?

Question

Does anyone know if its possible in any way to put two labels on the same line when writing in RISC-V. I can't seem to find an answer on the documentation.

Here is an example Where I want to compute the sum of every integer in the array.

v:  .word 5, 7, 7, -2, 0, 1, 1
n:  .word 7
    
.text
    lui s0, 0x10010
    lw s3, n
    jal jump
    
    li a7, 1
    ecall
    li a7, 10
    ecall


jump:loop:  lw t0, 0(s0)
            add s1, s1, t0
            addi s0, s0, 4 #or 0x1
            addi s3, s3, -1
            bne s3, zero, loop
            mv a0, s1
            jalr zero, ra, 0

I would like to put the labels jump and loop on the same line, but the syntax is not correct because written like this after the jump label riscv tries to read the line as if it was an instruction, not another label.

Answer 1

As far as the processor is concerned, there are no "lines", just machine code instructions.

As far as the assembler is concerned, labels are just name-value pairs where the value is an address, and there's nothing limiting the number of names to one single given address.

So, go ahead and put two labels on that instruction as follows:

jump:
loop:
    lw t0, 0(s0)
    add s1, s1, t0
    ...

As far as assembly programmers go, a label refer to a conceptual location in the code (or in the data) rather than necessarily to the instruction that comes next.

For example, with that code you may at some point insert some function prologue, it would go between jump: and loop:.

Compiler generated assembly often has more than one label at a given point, this happens, for example, when control flow statements translations end with a label (such as for if-then), and several control flow statements converge at an ending point (such as nested if-then statements).

While it is possible to "optimize" these double labels, since the processor doesn't see them anyway, it doesn't really make much of an optimization.