[PULL,26/26] target/ppc: do not call hreg_compute_hflags() in helper_store_mmcr0()

Commit Message

Cédric Le Goater Jan. 4, 2022, 7:31 a.m. UTC

From: Daniel Henrique Barboza <[e-mail]>

MMCR0 writes will change only MMCR0 bits which are used to calculate
HFLAGS_PMCC0, HFLAGS_PMCC1 and HFLAGS_INSN_CNT hflags. No other machine
register will be changed during this operation. This means that
hreg_compute_hflags() is overkill for what we need to do.

pmu_update_summaries() is already updating HFLAGS_INSN_CNT without
calling hreg_compure_hflags(). Let's do the same for the other 2 MMCR0
hflags.

Reviewed-by: Richard Henderson <[e-mail]>
Signed-off-by: Daniel Henrique Barboza <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Cédric Le Goater <[e-mail]>
---
 target/ppc/power8-pmu.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Patch

diff --git a/target/ppc/power8-pmu.c b/target/ppc/power8-pmu.c
index 73713ca2a320..236e8e66e966 100644
--- a/target/ppc/power8-pmu.c
+++ b/target/ppc/power8-pmu.c
@@ -224,12 +224,17 @@  static void pmu_update_overflow_timers(CPUPPCState *env)
 
 void helper_store_mmcr0(CPUPPCState *env, target_ulong value)
 {
+    bool hflags_pmcc0 = (value & MMCR0_PMCC0) != 0;
+    bool hflags_pmcc1 = (value & MMCR0_PMCC1) != 0;
+
     pmu_update_cycles(env);
 
     env->spr[SPR_POWER_MMCR0] = value;
 
     /* MMCR0 writes can change HFLAGS_PMCC[01] and HFLAGS_INSN_CNT */
-    hreg_compute_hflags(env);
+    env->hflags = deposit32(env->hflags, HFLAGS_PMCC0, 1, hflags_pmcc0);
+    env->hflags = deposit32(env->hflags, HFLAGS_PMCC1, 1, hflags_pmcc1);
+
     pmu_update_summaries(env);
 
     /* Update cycle overflow timers with the current MMCR0 state */