iASL: Optimization for FieldUnit lists

Ignore a field unit that is both unnamed and has a length of zero.
Previously, two zero bytes were emitted for no good reason.

1 files changed, 14 insertions, 0 deletions

diff --git a/source/compiler/asloperands.c b/source/compiler/asloperands.c
index 2e2f2d108..db4d013c1 100644
--- a/source/compiler/asloperands.c
+++ b/source/compiler/asloperands.c
@@ -423,6 +423,20 @@ OpnDoFieldCommon (
             NewBitOffset = (UINT32) PkgLengthNode->Asl.Value.Integer;
             CurrentBitOffset += NewBitOffset;
 
+            if ((NewBitOffset == 0) &&
+                (Next->Asl.ParseOpcode == PARSEOP_RESERVED_BYTES))
+            {
+                /*
+                 * Unnamed field with a bit length of zero. We can
+                 * safely just ignore this. However, we will not ignore
+                 * a named field of zero length, we don't want to just
+                 * toss out a name.
+                 */
+                Next->Asl.ParseOpcode = PARSEOP_DEFAULT_ARG;
+                PkgLengthNode->Asl.ParseOpcode = PARSEOP_DEFAULT_ARG;
+                break;
+            }
+
             /* Save the current AccessAs value for error checking later */
 
             switch (AccessType)