Re: [Qemu-devel] [PATCH 2/4] tcg/aarch64: implement new TCG target for aarch64

[Peter Maydell]

On 23 May 2013 09:18, Claudio Fontana <address@hidden> wrote:
>
> add preliminary support for TCG target aarch64.

Richard's handling the technical bits of the review, so
just some minor style nits here.

I tested this on the foundation model and was able to boot
a 32-bit-ARM kernel.

> +static inline void reloc_pc19(void *code_ptr, tcg_target_long target)
> +{
> +    tcg_target_long offset; uint32_t insn;
> +    offset = (target - (tcg_target_long)code_ptr) / 4;
> +    offset &= 0x07ffff;
> +    /* read instruction, mask away previous PC_REL19 parameter contents,
> +       set the proper offset, then write back the instruction. */
> +    insn = *(uint32_t *)code_ptr;
> +    insn = (insn & 0xff00001f) | offset << 5; /* lower 5 bits = condition */

You can say
    insn = deposit32(insn, 5, 19, offset);
here rather than doing
    offset &= 0x07ffff;
    insn = (insn & 0xff00001f) | offset << 5;

(might as well also use deposit32 for consistency in the pc26 function.)

> +static inline enum aarch64_ldst_op_data
> +aarch64_ldst_get_data(TCGOpcode tcg_op)
> +{
> +    switch (tcg_op) {
> +    case INDEX_op_ld8u_i32: case INDEX_op_ld8s_i32:
> +    case INDEX_op_ld8u_i64: case INDEX_op_ld8s_i64:
> +    case INDEX_op_st8_i32: case INDEX_op_st8_i64:

One case per line, please (here and elsewhere).

> +static inline void tcg_out_call(TCGContext *s, tcg_target_long target)
> +{
> +    tcg_target_long offset;
> +
> +    offset = (target - (tcg_target_long)s->code_ptr) / 4;
> +
> +    if (offset <= -0x02000000 || offset >= 0x02000000) { /* out of 26bit rng 
> */
> +        tcg_out_movi64(s, TCG_REG_TMP, target);
> +        tcg_out_callr(s, TCG_REG_TMP);
> +

Stray blank line.

> +    case INDEX_op_mov_i64: ext = 1;

Please don't put code on the same line as a case statement.
Also fall-through cases should have an explicit /* fall through */
comment (except in the case where there is no code at all
between one case statement and the next).

thanks
-- PMM