Re: [PATCH 2/6] target/ppc: optimize hreg_compute_pmu_hflags_value

[BALATON Zoltan]

On Mon, 20 May 2024, Harsh Prateek Bora wrote:
Cache env->spr[SPR_POWER_MMCR0] in a local variable as used in multiple
conditions to avoid multiple indirect accesses.
Signed-off-by: Harsh Prateek Bora <hars...@linux.ibm.com>
---
target/ppc/helper_regs.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
index 945fa1a596..5de0df5795 100644
--- a/target/ppc/helper_regs.c
+++ b/target/ppc/helper_regs.c
@@ -50,15 +50,16 @@ void hreg_swap_gpr_tgpr(CPUPPCState *env)
static uint32_t hreg_compute_pmu_hflags_value(CPUPPCState *env)
{
    uint32_t hflags = 0;
-
#if defined(TARGET_PPC64)
-    if (env->spr[SPR_POWER_MMCR0] & MMCR0_PMCC0) {
+    target_ulong spr_power_mmcr0 = env->spr[SPR_POWER_MMCR0];

I think this is simple enough so the compiler should be able to find out 
on its own but adding a local is also simple and may make it more readable 
but I'd call it just mmcr0 for readability.

Regards,
BALATON Zoltan

+
+    if (spr_power_mmcr0 & MMCR0_PMCC0) {
        hflags |= 1 << HFLAGS_PMCC0;
    }
-    if (env->spr[SPR_POWER_MMCR0] & MMCR0_PMCC1) {
+    if (spr_power_mmcr0 & MMCR0_PMCC1) {
        hflags |= 1 << HFLAGS_PMCC1;
    }
-    if (env->spr[SPR_POWER_MMCR0] & MMCR0_PMCjCE) {
+    if (spr_power_mmcr0 & MMCR0_PMCjCE) {
        hflags |= 1 << HFLAGS_PMCJCE;
    }