| Message ID | 20170614194821.8754-2-rth@twiddle.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Richard Henderson <rth@twiddle.net> writes: > We can call tb_htable_lookup even when the tb_jmp_cache > is completely empty. Therefore, un-nest most of the code > dependent on tb != NULL from the read from the cache. > > Signed-off-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > --- > tcg-runtime.c | 34 ++++++++++++++++++---------------- > 1 file changed, 18 insertions(+), 16 deletions(-) > > diff --git a/tcg-runtime.c b/tcg-runtime.c > index 7fa90ce..a35c725 100644 > --- a/tcg-runtime.c > +++ b/tcg-runtime.c > @@ -147,30 +147,32 @@ uint64_t HELPER(ctpop_i64)(uint64_t arg) > void *HELPER(lookup_tb_ptr)(CPUArchState *env, target_ulong addr) > { > CPUState *cpu = ENV_GET_CPU(env); > + void *ret = tcg_ctx.code_gen_epilogue; > TranslationBlock *tb; > target_ulong cs_base, pc; > - uint32_t flags; > - > - tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)]); > - if (likely(tb)) { > - cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); > - if (likely(tb->pc == addr && tb->cs_base == cs_base && > - tb->flags == flags)) { > - goto found; > - } > + uint32_t flags, addr_hash; > + > + addr_hash = tb_jmp_cache_hash_func(addr); > + tb = atomic_rcu_read(&cpu->tb_jmp_cache[addr_hash]); > + cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); > + > + if (unlikely(!(tb > + && tb->pc == addr > + && tb->cs_base == cs_base > + && tb->flags == flags))) { > tb = tb_htable_lookup(cpu, addr, cs_base, flags); > - if (likely(tb)) { > - atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)], tb); > - goto found; > + if (!tb) { > + return ret; > } > + atomic_set(&cpu->tb_jmp_cache[addr_hash], tb); > } > - return tcg_ctx.code_gen_epilogue; > - found: > + > + ret = tb->tc_ptr; > qemu_log_mask_and_addr(CPU_LOG_EXEC, addr, > "Chain %p [%d: " TARGET_FMT_lx "] %s\n", > - tb->tc_ptr, cpu->cpu_index, addr, > + ret, cpu->cpu_index, addr, > lookup_symbol(addr)); > - return tb->tc_ptr; > + return ret; > } > > void HELPER(exit_atomic)(CPUArchState *env) -- Alex Bennée
diff --git a/tcg-runtime.c b/tcg-runtime.c index 7fa90ce..a35c725 100644 --- a/tcg-runtime.c +++ b/tcg-runtime.c @@ -147,30 +147,32 @@ uint64_t HELPER(ctpop_i64)(uint64_t arg) void *HELPER(lookup_tb_ptr)(CPUArchState *env, target_ulong addr) { CPUState *cpu = ENV_GET_CPU(env); + void *ret = tcg_ctx.code_gen_epilogue; TranslationBlock *tb; target_ulong cs_base, pc; - uint32_t flags; - - tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)]); - if (likely(tb)) { - cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); - if (likely(tb->pc == addr && tb->cs_base == cs_base && - tb->flags == flags)) { - goto found; - } + uint32_t flags, addr_hash; + + addr_hash = tb_jmp_cache_hash_func(addr); + tb = atomic_rcu_read(&cpu->tb_jmp_cache[addr_hash]); + cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); + + if (unlikely(!(tb + && tb->pc == addr + && tb->cs_base == cs_base + && tb->flags == flags))) { tb = tb_htable_lookup(cpu, addr, cs_base, flags); - if (likely(tb)) { - atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)], tb); - goto found; + if (!tb) { + return ret; } + atomic_set(&cpu->tb_jmp_cache[addr_hash], tb); } - return tcg_ctx.code_gen_epilogue; - found: + + ret = tb->tc_ptr; qemu_log_mask_and_addr(CPU_LOG_EXEC, addr, "Chain %p [%d: " TARGET_FMT_lx "] %s\n", - tb->tc_ptr, cpu->cpu_index, addr, + ret, cpu->cpu_index, addr, lookup_symbol(addr)); - return tb->tc_ptr; + return ret; } void HELPER(exit_atomic)(CPUArchState *env)
We can call tb_htable_lookup even when the tb_jmp_cache is completely empty. Therefore, un-nest most of the code dependent on tb != NULL from the read from the cache. Signed-off-by: Richard Henderson <rth@twiddle.net> --- tcg-runtime.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-)