[PATCH 4/6] target/ppc: optimize p9 exception handling routines

[Harsh Prateek Bora]

Currently, p9 exception handling has multiple if-condition checks where
it does an indirect access to pending_interrupts via env. Cache the
value during entry and reuse later to avoid multiple indirect accesses.

Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
---
 target/ppc/excp_helper.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 0712098cf7..4f158196bb 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -1844,8 +1844,10 @@ static int p8_next_unmasked_interrupt(CPUPPCState *env)
 
 static int p9_interrupt_powersave(CPUPPCState *env)
 {
+    uint32_t pending_interrupts = env->pending_interrupts;
+
     /* External Exception */
-    if ((env->pending_interrupts & PPC_INTERRUPT_EXT) &&
+    if ((pending_interrupts & PPC_INTERRUPT_EXT) &&
         (env->spr[SPR_LPCR] & LPCR_EEE)) {
         bool heic = !!(env->spr[SPR_LPCR] & LPCR_HEIC);
         if (!heic || !FIELD_EX64_HV(env->msr) ||
@@ -1854,35 +1856,35 @@ static int p9_interrupt_powersave(CPUPPCState *env)
         }
     }
     /* Decrementer Exception */
-    if ((env->pending_interrupts & PPC_INTERRUPT_DECR) &&
+    if ((pending_interrupts & PPC_INTERRUPT_DECR) &&
         (env->spr[SPR_LPCR] & LPCR_DEE)) {
         return PPC_INTERRUPT_DECR;
     }
     /* Machine Check or Hypervisor Maintenance Exception */
     if (env->spr[SPR_LPCR] & LPCR_OEE) {
-        if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
+        if (pending_interrupts & PPC_INTERRUPT_MCK) {
             return PPC_INTERRUPT_MCK;
         }
-        if (env->pending_interrupts & PPC_INTERRUPT_HMI) {
+        if (pending_interrupts & PPC_INTERRUPT_HMI) {
             return PPC_INTERRUPT_HMI;
         }
     }
     /* Privileged Doorbell Exception */
-    if ((env->pending_interrupts & PPC_INTERRUPT_DOORBELL) &&
+    if ((pending_interrupts & PPC_INTERRUPT_DOORBELL) &&
         (env->spr[SPR_LPCR] & LPCR_PDEE)) {
         return PPC_INTERRUPT_DOORBELL;
     }
     /* Hypervisor Doorbell Exception */
-    if ((env->pending_interrupts & PPC_INTERRUPT_HDOORBELL) &&
+    if ((pending_interrupts & PPC_INTERRUPT_HDOORBELL) &&
         (env->spr[SPR_LPCR] & LPCR_HDEE)) {
         return PPC_INTERRUPT_HDOORBELL;
     }
     /* Hypervisor virtualization exception */
-    if ((env->pending_interrupts & PPC_INTERRUPT_HVIRT) &&
+    if ((pending_interrupts & PPC_INTERRUPT_HVIRT) &&
         (env->spr[SPR_LPCR] & LPCR_HVEE)) {
         return PPC_INTERRUPT_HVIRT;
     }
-    if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
+    if (pending_interrupts & PPC_INTERRUPT_RESET) {
         return PPC_INTERRUPT_RESET;
     }
     return 0;
@@ -1891,11 +1893,12 @@ static int p9_interrupt_powersave(CPUPPCState *env)
 static int p9_next_unmasked_interrupt(CPUPPCState *env)
 {
     CPUState *cs = env_cpu(env);
+    uint32_t pending_interrupts = env->pending_interrupts;
 
     /* Ignore MSR[EE] when coming out of some power management states */
     bool msr_ee = FIELD_EX64(env->msr, MSR, EE) || env->resume_as_sreset;
 
-    assert((env->pending_interrupts & P9_UNUSED_INTERRUPTS) == 0);
+    assert((pending_interrupts & P9_UNUSED_INTERRUPTS) == 0);
 
     if (cs->halted) {
         if (env->spr[SPR_PSSCR] & PSSCR_EC) {
@@ -1914,12 +1917,12 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env)
     }
 
     /* Machine check exception */
-    if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
+    if (pending_interrupts & PPC_INTERRUPT_MCK) {
         return PPC_INTERRUPT_MCK;
     }
 
     /* Hypervisor decrementer exception */
-    if (env->pending_interrupts & PPC_INTERRUPT_HDECR) {
+    if (pending_interrupts & PPC_INTERRUPT_HDECR) {
         /* LPCR will be clear when not supported so this will work */
         bool hdice = !!(env->spr[SPR_LPCR] & LPCR_HDICE);
         if ((msr_ee || !FIELD_EX64_HV(env->msr)) && hdice) {
@@ -1929,7 +1932,7 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env)
     }
 
     /* Hypervisor virtualization interrupt */
-    if (env->pending_interrupts & PPC_INTERRUPT_HVIRT) {
+    if (pending_interrupts & PPC_INTERRUPT_HVIRT) {
         /* LPCR will be clear when not supported so this will work */
         bool hvice = !!(env->spr[SPR_LPCR] & LPCR_HVICE);
         if ((msr_ee || !FIELD_EX64_HV(env->msr)) && hvice) {
@@ -1938,7 +1941,7 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env)
     }
 
     /* External interrupt can ignore MSR:EE under some circumstances */
-    if (env->pending_interrupts & PPC_INTERRUPT_EXT) {
+    if (pending_interrupts & PPC_INTERRUPT_EXT) {
         bool lpes0 = !!(env->spr[SPR_LPCR] & LPCR_LPES0);
         bool heic = !!(env->spr[SPR_LPCR] & LPCR_HEIC);
         /* HEIC blocks delivery to the hypervisor */
@@ -1950,20 +1953,20 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env)
     }
     if (msr_ee != 0) {
         /* Decrementer exception */
-        if (env->pending_interrupts & PPC_INTERRUPT_DECR) {
+        if (pending_interrupts & PPC_INTERRUPT_DECR) {
             return PPC_INTERRUPT_DECR;
         }
-        if (env->pending_interrupts & PPC_INTERRUPT_DOORBELL) {
+        if (pending_interrupts & PPC_INTERRUPT_DOORBELL) {
             return PPC_INTERRUPT_DOORBELL;
         }
-        if (env->pending_interrupts & PPC_INTERRUPT_HDOORBELL) {
+        if (pending_interrupts & PPC_INTERRUPT_HDOORBELL) {
             return PPC_INTERRUPT_HDOORBELL;
         }
-        if (env->pending_interrupts & PPC_INTERRUPT_PERFM) {
+        if (pending_interrupts & PPC_INTERRUPT_PERFM) {
             return PPC_INTERRUPT_PERFM;
         }
         /* EBB exception */
-        if (env->pending_interrupts & PPC_INTERRUPT_EBB) {
+        if (pending_interrupts & PPC_INTERRUPT_EBB) {
             /*
              * EBB exception must be taken in problem state and
              * with BESCR_GE set.
-- 
2.39.3