| Message ID | 20241207214700.211066-1-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | tcg: Reset free_temps before tcg_optimize | expand |
On 12/7/24 13:47, 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. > > 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> > --- > > Unless there's some other reason to spin an -rc4, this can wait > to be the first patch for 10.0.1. > > r~ > > --- > tcg/tcg.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/tcg/tcg.c b/tcg/tcg.c > index 0babae1b88..eece825e2e 100644 > --- a/tcg/tcg.c > +++ b/tcg/tcg.c > @@ -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. */ > + memset(s->free_temps, 0, sizeof(s->free_temps)); > + > tcg_optimize(s); > > reachable_code_pass(s); Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
On 7/12/24 22:47, 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. > > Cc: qemu-stable@nongnu.org > Fixes: fb04ab7ddd8 ("tcg/optimize: Lower TCG_COND_TST{EQ,NE} if unsupported") Hmm, the problem is due to arg_new_temp()? > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2711 > Reported-by: wannacu <wannacu2049@gmail.com> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > > Unless there's some other reason to spin an -rc4, this can wait > to be the first patch for 10.0.1. > > r~ > > --- > tcg/tcg.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/tcg/tcg.c b/tcg/tcg.c > index 0babae1b88..eece825e2e 100644 > --- a/tcg/tcg.c > +++ b/tcg/tcg.c > @@ -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. */ > + memset(s->free_temps, 0, sizeof(s->free_temps)); Maybe add as tcg_temp_[ebb]_[reset|flush]() helper so we can reuse, like in tcg_func_start() and plugin_gen_inject()? > tcg_optimize(s); > > reachable_code_pass(s);
On 12/8/24 12:01, Philippe Mathieu-Daudé wrote: > On 7/12/24 22:47, 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. >> >> Cc: qemu-stable@nongnu.org >> Fixes: fb04ab7ddd8 ("tcg/optimize: Lower TCG_COND_TST{EQ,NE} if unsupported") > > Hmm, the problem is due to arg_new_temp()? Yes. > Maybe add as tcg_temp_[ebb]_[reset|flush]() helper so we can reuse, > like in tcg_func_start() and plugin_gen_inject()? Ah, right. I had a memory of solving this same problem once, but couldn't remember where, or if it was on a branch somewhere. Good idea. r~
diff --git a/tcg/tcg.c b/tcg/tcg.c index 0babae1b88..eece825e2e 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -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. */ + memset(s->free_temps, 0, sizeof(s->free_temps)); + 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. 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> --- Unless there's some other reason to spin an -rc4, this can wait to be the first patch for 10.0.1. r~ --- tcg/tcg.c | 3 +++ 1 file changed, 3 insertions(+)