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author | Richard Henderson <richard.henderson@linaro.org> | 2019-10-23 11:00:57 -0400 |
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committer | Peter Maydell <peter.maydell@linaro.org> | 2019-10-24 17:16:28 +0100 |
commit | e979972a6a17baadfcef05952e7523af99489487 (patch) | |
tree | eb43b8cf0570e0677153924dd7fca3be2104b97f /target | |
parent | 37bf16c645e530b2a4434fd5976afbe885137298 (diff) | |
download | qemu-e979972a6a17baadfcef05952e7523af99489487.zip qemu-e979972a6a17baadfcef05952e7523af99489487.tar.gz qemu-e979972a6a17baadfcef05952e7523af99489487.tar.bz2 |
target/arm: Rely on hflags correct in cpu_get_tb_cpu_state
This is the payoff.
From perf record -g data of ubuntu 18 boot and shutdown:
BEFORE:
- 23.02% 2.82% qemu-system-aar [.] helper_lookup_tb_ptr
- 20.22% helper_lookup_tb_ptr
+ 10.05% tb_htable_lookup
- 9.13% cpu_get_tb_cpu_state
3.20% aa64_va_parameters_both
0.55% fp_exception_el
- 11.66% 4.74% qemu-system-aar [.] cpu_get_tb_cpu_state
- 6.96% cpu_get_tb_cpu_state
3.63% aa64_va_parameters_both
0.60% fp_exception_el
0.53% sve_exception_el
AFTER:
- 16.40% 3.40% qemu-system-aar [.] helper_lookup_tb_ptr
- 13.03% helper_lookup_tb_ptr
+ 11.19% tb_htable_lookup
0.55% cpu_get_tb_cpu_state
0.98% 0.71% qemu-system-aar [.] cpu_get_tb_cpu_state
0.87% 0.24% qemu-system-aar [.] rebuild_hflags_a64
Before, helper_lookup_tb_ptr is the second hottest function in the
application, consuming almost a quarter of the runtime. Within the
entire execution, cpu_get_tb_cpu_state consumes about 12%.
After, helper_lookup_tb_ptr has dropped to the fourth hottest function,
with consumption dropping to a sixth of the runtime. Within the
entire execution, cpu_get_tb_cpu_state has dropped below 1%, and the
supporting function to rebuild hflags also consumes about 1%.
Assertions are retained for --enable-debug-tcg.
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191023150057.25731-25-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target')
-rw-r--r-- | target/arm/helper.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c index c55783e..63815fc 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -11259,12 +11259,15 @@ void HELPER(rebuild_hflags_a64)(CPUARMState *env, int el) void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, target_ulong *cs_base, uint32_t *pflags) { - uint32_t flags, pstate_for_ss; + uint32_t flags = env->hflags; + uint32_t pstate_for_ss; *cs_base = 0; - flags = rebuild_hflags_internal(env); +#ifdef CONFIG_DEBUG_TCG + assert(flags == rebuild_hflags_internal(env)); +#endif - if (is_a64(env)) { + if (FIELD_EX32(flags, TBFLAG_ANY, AARCH64_STATE)) { *pc = env->pc; if (cpu_isar_feature(aa64_bti, env_archcpu(env))) { flags = FIELD_DP32(flags, TBFLAG_A64, BTYPE, env->btype); |