| Message ID | 20241210145253.1822737-1-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] tcg: Reset free_temps before tcg_optimize | expand |
On 10/12/24 15:52, Richard Henderson wrote: > When allocating new temps during tcg_optmize, do not re-use > any EBB temps that were used within the TB. We do not have > any idea what span of the TB in which the temp was live. > > Introduce tcg_temp_ebb_reset_freed and use before tcg_optimize, > as well as replacing the equivalent in plugin_gen_inject and > tcg_func_start. > > Cc: qemu-stable@nongnu.org > Fixes: fb04ab7ddd8 ("tcg/optimize: Lower TCG_COND_TST{EQ,NE} if unsupported") > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2711 > Reported-by: wannacu <wannacu2049@gmail.com> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> > --- > include/tcg/tcg-temp-internal.h | 6 ++++++ > accel/tcg/plugin-gen.c | 2 +- > tcg/tcg.c | 5 ++++- > 3 files changed, 11 insertions(+), 2 deletions(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff --git a/include/tcg/tcg-temp-internal.h b/include/tcg/tcg-temp-internal.h index 44192c55a9..98f91e68b7 100644 --- a/include/tcg/tcg-temp-internal.h +++ b/include/tcg/tcg-temp-internal.h @@ -42,4 +42,10 @@ TCGv_i64 tcg_temp_ebb_new_i64(void); TCGv_ptr tcg_temp_ebb_new_ptr(void); TCGv_i128 tcg_temp_ebb_new_i128(void); +/* Forget all freed EBB temps, so that new allocations produce new temps. */ +static inline void tcg_temp_ebb_reset_freed(TCGContext *s) +{ + memset(s->free_temps, 0, sizeof(s->free_temps)); +} + #endif /* TCG_TEMP_FREE_H */ diff --git a/accel/tcg/plugin-gen.c b/accel/tcg/plugin-gen.c index 0f47bfbb48..1ef075552c 100644 --- a/accel/tcg/plugin-gen.c +++ b/accel/tcg/plugin-gen.c @@ -275,7 +275,7 @@ static void plugin_gen_inject(struct qemu_plugin_tb *plugin_tb) * that might be live within the existing opcode stream. * The simplest solution is to release them all and create new. */ - memset(tcg_ctx->free_temps, 0, sizeof(tcg_ctx->free_temps)); + tcg_temp_ebb_reset_freed(tcg_ctx); QTAILQ_FOREACH_SAFE(op, &tcg_ctx->ops, link, next) { switch (op->opc) { diff --git a/tcg/tcg.c b/tcg/tcg.c index 0babae1b88..4578b185be 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -1489,7 +1489,7 @@ void tcg_func_start(TCGContext *s) s->nb_temps = s->nb_globals; /* No temps have been previously allocated for size or locality. */ - memset(s->free_temps, 0, sizeof(s->free_temps)); + tcg_temp_ebb_reset_freed(s); /* No constant temps have been previously allocated. */ for (int i = 0; i < TCG_TYPE_COUNT; ++i) { @@ -6120,6 +6120,9 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb, uint64_t pc_start) } #endif + /* Do not reuse any EBB that may be allocated within the TB. */ + tcg_temp_ebb_reset_freed(s); + tcg_optimize(s); reachable_code_pass(s);
When allocating new temps during tcg_optmize, do not re-use any EBB temps that were used within the TB. We do not have any idea what span of the TB in which the temp was live. Introduce tcg_temp_ebb_reset_freed and use before tcg_optimize, as well as replacing the equivalent in plugin_gen_inject and tcg_func_start. Cc: qemu-stable@nongnu.org Fixes: fb04ab7ddd8 ("tcg/optimize: Lower TCG_COND_TST{EQ,NE} if unsupported") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2711 Reported-by: wannacu <wannacu2049@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> --- include/tcg/tcg-temp-internal.h | 6 ++++++ accel/tcg/plugin-gen.c | 2 +- tcg/tcg.c | 5 ++++- 3 files changed, 11 insertions(+), 2 deletions(-)