commit eeaaefe9fa8b95a7ed39ee86257f3bf1af751804
author Leandro Lupori <leandro.lupori@eldorado.org.br> Tue Oct 25 17:24:24 2022 -0300
committer Daniel Henrique Barboza <danielhb413@gmail.com> Fri Oct 28 13:15:23 2022 -0300
tree 68aae0fe616f09eb7060a4573a6069307bd34957
parent 8b3d1c49a9f0f315d2b292c1791430c0f382afa4

target/ppc: Increment PMC5 with inline insns

Profiling QEMU during Fedora 35 for PPC64 boot revealed that
6.39% of total time was being spent in helper_insns_inc(), on a
POWER9 machine. To avoid calling this helper every time PMCs had
to be incremented, an inline implementation of PMC5 increment and
check for overflow was developed. This led to a reduction of
about 12% in Fedora's boot time.

Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20221025202424.195984-4-leandro.lupori@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

target/ppc/power8-pmu.c

diff --git a/target/ppc/power8-pmu.c b/target/ppc/power8-pmu.c
index beeab5c..1381072 100644
--- a/target/ppc/power8-pmu.c
+++ b/target/ppc/power8-pmu.c
@@ -22,8 +22,6 @@
 
 #if defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY)
 
-#define PMC_COUNTER_NEGATIVE_VAL 0x80000000UL
-
 static bool pmc_has_overflow_enabled(CPUPPCState *env, int sprn)
 {
     if (sprn == SPR_POWER_PMC1) {
@@ -88,49 +86,47 @@
     bool overflow_triggered = false;
     target_ulong tmp;
 
-    if (unlikely(ins_cnt & 0x1e)) {
-        if (ins_cnt & (1 << 1)) {
-            tmp = env->spr[SPR_POWER_PMC1];
-            tmp += num_insns;
-            if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMC1CE)) {
-                tmp = PMC_COUNTER_NEGATIVE_VAL;
-                overflow_triggered = true;
-            }
-            env->spr[SPR_POWER_PMC1] = tmp;
+    if (ins_cnt & (1 << 1)) {
+        tmp = env->spr[SPR_POWER_PMC1];
+        tmp += num_insns;
+        if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMC1CE)) {
+            tmp = PMC_COUNTER_NEGATIVE_VAL;
+            overflow_triggered = true;
         }
+        env->spr[SPR_POWER_PMC1] = tmp;
+    }
 
-        if (ins_cnt & (1 << 2)) {
-            tmp = env->spr[SPR_POWER_PMC2];
+    if (ins_cnt & (1 << 2)) {
+        tmp = env->spr[SPR_POWER_PMC2];
+        tmp += num_insns;
+        if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMCjCE)) {
+            tmp = PMC_COUNTER_NEGATIVE_VAL;
+            overflow_triggered = true;
+        }
+        env->spr[SPR_POWER_PMC2] = tmp;
+    }
+
+    if (ins_cnt & (1 << 3)) {
+        tmp = env->spr[SPR_POWER_PMC3];
+        tmp += num_insns;
+        if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMCjCE)) {
+            tmp = PMC_COUNTER_NEGATIVE_VAL;
+            overflow_triggered = true;
+        }
+        env->spr[SPR_POWER_PMC3] = tmp;
+    }
+
+    if (ins_cnt & (1 << 4)) {
+        target_ulong mmcr1 = env->spr[SPR_POWER_MMCR1];
+        int sel = extract64(mmcr1, MMCR1_PMC4EVT_EXTR, MMCR1_EVT_SIZE);
+        if (sel == 0x02 || (env->spr[SPR_CTRL] & CTRL_RUN)) {
+            tmp = env->spr[SPR_POWER_PMC4];
             tmp += num_insns;
             if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMCjCE)) {
                 tmp = PMC_COUNTER_NEGATIVE_VAL;
                 overflow_triggered = true;
             }
-            env->spr[SPR_POWER_PMC2] = tmp;
-        }
-
-        if (ins_cnt & (1 << 3)) {
-            tmp = env->spr[SPR_POWER_PMC3];
-            tmp += num_insns;
-            if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMCjCE)) {
-                tmp = PMC_COUNTER_NEGATIVE_VAL;
-                overflow_triggered = true;
-            }
-            env->spr[SPR_POWER_PMC3] = tmp;
-        }
-
-        if (ins_cnt & (1 << 4)) {
-            target_ulong mmcr1 = env->spr[SPR_POWER_MMCR1];
-            int sel = extract64(mmcr1, MMCR1_PMC4EVT_EXTR, MMCR1_EVT_SIZE);
-            if (sel == 0x02 || (env->spr[SPR_CTRL] & CTRL_RUN)) {
-                tmp = env->spr[SPR_POWER_PMC4];
-                tmp += num_insns;
-                if (tmp >= PMC_COUNTER_NEGATIVE_VAL && (mmcr0 & MMCR0_PMCjCE)) {
-                    tmp = PMC_COUNTER_NEGATIVE_VAL;
-                    overflow_triggered = true;
-                }
-                env->spr[SPR_POWER_PMC4] = tmp;
-            }
+            env->spr[SPR_POWER_PMC4] = tmp;
         }
     }
 
@@ -310,6 +306,12 @@
     raise_ebb_perfm_exception(env);
 }
 
+void helper_handle_pmc5_overflow(CPUPPCState *env)
+{
+    env->spr[SPR_POWER_PMC5] = PMC_COUNTER_NEGATIVE_VAL;
+    fire_PMC_interrupt(env_archcpu(env));
+}
+
 /* This helper assumes that the PMC is running. */
 void helper_insns_inc(CPUPPCState *env, uint32_t num_insns)
 {