diff --git a/src/drivers/intel/gma/acpi/common.asl b/src/drivers/intel/gma/acpi/common.asl
index 254a66d605..02169ae874 100644
--- a/src/drivers/intel/gma/acpi/common.asl
+++ b/src/drivers/intel/gma/acpi/common.asl
@@ -9,7 +9,7 @@
 		Store (Match (BRIG, MEQ, Arg0, MTR, Zero, 2), Local0)
 		If (LEqual (Local0, Ones))
 		{
-			Return (Subtract(SizeOf(BRIG), One))
+			Return (SizeOf(BRIG) - 1)
 		}
 		Return (Local0)
 	}
@@ -56,7 +56,7 @@
 			Notify (LCD0, 0x86)
 		} Else {
 			Store (BRID (XBQC ()), Local0)
-			If (LNotEqual (Local0, Subtract(SizeOf(BRIG), One)))
+			If (LNotEqual (Local0, SizeOf(BRIG) - 1))
 			{
 				Increment (Local0)
 			}
diff --git a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
index 92ae766661..3581f4d30c 100644
--- a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
+++ b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
@@ -121,15 +121,13 @@
 
 			/* Local1: loop index (selectable values start at 2 in BRIG) */
 			Store (2, Local1)
-			While (LLess (Local1, Subtract (SizeOf (BRIG), 1))) {
+			While (LLess (Local1, SizeOf (BRIG) - 1)) {
 				/* Local[23]: adjacent values in BRIG */
 				Store (DeRefOf (BRIG[Local1]), Local2)
 				Store (DeRefOf (BRIG[Add (Local1, 1)]), Local3)
 
 				If (LLess (Local0, Local3)) {
-					If (LOr (LLess (Local0, Local2),
-						 LLess (Subtract (Local0, Local2),
-							Subtract (Local3, Local0)))) {
+					If (LOr (LLess (Local0, Local2), LLess (Local0 - Local2, Local3 - Local0))) {
 						Return (Local2)
 					} Else {
 						Return (Local3)