target/ppc: do not call hreg_compute_hflags() in helper_store_mmcr0()

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 <richard.henderson@linaro.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220103224746.167831-5-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

diff --git a/target/ppc/power8-pmu.c b/target/ppc/power8-pmu.c
index 73713ca2a320f8d67724bc4bb45f0c71106ac09e..236e8e66e966951bd44800abbfa8be202754e82e 100644 (file)
--- 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 */