On Mon, 12 Jul 2021 at 16:42, Richard Henderson
<richard.hender...@linaro.org> wrote:
>
> The space reserved for CF_COUNT_MASK was overly large.
> Reduce to free up cflags bits and eliminate an extra test.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> include/exec/exec-all.h | 4 +++-
> accel/tcg/translate-all.c | 5 ++---
> 2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index 754f4130c9..dfe82ed19c 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -492,7 +492,9 @@ struct TranslationBlock {
> target_ulong cs_base; /* CS base for this block */
> uint32_t flags; /* flags defining in which context the code was
> generated */
> uint32_t cflags; /* compile flags */
> -#define CF_COUNT_MASK 0x00007fff
> +
> +/* Note that TCG_MAX_INSNS is 512; we validate this match elsewhere. */
> +#define CF_COUNT_MASK 0x000001ff
> #define CF_LAST_IO 0x00008000 /* Last insn may be an IO access. */
> #define CF_MEMI_ONLY 0x00010000 /* Only instrument memory ops */
> #define CF_USE_ICOUNT 0x00020000
> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index 4df26de858..997e44c73b 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -1430,9 +1430,8 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
> if (max_insns == 0) {
> max_insns = CF_COUNT_MASK;
> }
> - if (max_insns > TCG_MAX_INSNS) {
> - max_insns = TCG_MAX_INSNS;
> - }
> + QEMU_BUILD_BUG_ON(CF_COUNT_MASK + 1 != TCG_MAX_INSNS);
> +
Previously we would allow max_insns = TCG_MAX_INSNS (512).
Now we only allow it to be 511...
-- PMM
