[PATCH 1/2] acpi: remove unnecessary reads

[Michael S. Tsirkin]

Read each of the up/down registers only once
and store in a local temporary.
This refactoring makes it a bit easier to
clear these registers, which is done by a follow-up patch.

Signed-off-by: Michael S. Tsirkin 
---
 src/acpi-dsdt.dsl |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/acpi-dsdt.dsl b/src/acpi-dsdt.dsl
index 4e04c48..15201e9 100644
--- a/src/acpi-dsdt.dsl
+++ b/src/acpi-dsdt.dsl
@@ -487,12 +487,14 @@ DefinitionBlock (
         Method(PCNF, 0) {
             // Local0 = iterator
             Store (Zero, Local0)
+            Store (PCIU, Local1)
+            Store (PCID, Local2)
             While (LLess(Local0, 31)) {
                 Increment(Local0)
-                If (And(PCIU, ShiftLeft(1, Local0))) {
+                If (And(Local1, ShiftLeft(1, Local0))) {
                     PCNT(Local0, 1)
                 }
-                If (And(PCID, ShiftLeft(1, Local0))) {
+                If (And(Local2, ShiftLeft(1, Local0))) {
                     PCNT(Local0, 3)
                 }
             }