Only arity 0 print accesses $_

We can reduce this deoptimization to when print is called with no arguments. Other forms do not need access to $_.
headius · May 21, 2024 · b5f94a9 · b5f94a9
1 parent 309ef8d
commit b5f94a9
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/core/src/main/java/org/jruby/ir/instructions/CallBase.java b/core/src/main/java/org/jruby/ir/instructions/CallBase.java
@@ -470,6 +470,14 @@ private void captureFrameReadsAndWrites() {
                 frameWrites = ALL;
             }
         } else {
+            // special cases
+            if (getId().equals("print") && argsCount != 0) {
+                // only arity 0 print requirest access to LASTLINE
+                frameReads = Collections.EMPTY_SET;
+                frameWrites = Collections.EMPTY_SET;
+                return;
+            }
+
             frameReads = MethodIndex.METHOD_FRAME_READS.getOrDefault(getId(), Collections.EMPTY_SET);
             frameWrites = MethodIndex.METHOD_FRAME_WRITES.getOrDefault(getId(), Collections.EMPTY_SET);
         }