[IR] Fix a RAW-hazard bug in Local Optimization Pass that had never s…

…howed up till now because we were rarely reusing temporary variables in IR generation so far.
carsonmcdonald · Oct 14, 2011 · 7ee5ba0 · 7ee5ba0
1 parent 4251d26
commit 7ee5ba0
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/src/org/jruby/compiler/ir/compiler_pass/opts/LocalOptimizationPass.java b/src/org/jruby/compiler/ir/compiler_pass/opts/LocalOptimizationPass.java
@@ -6,6 +6,7 @@
 import java.util.ArrayList;
 import java.util.ListIterator;
 
+import org.jruby.RubyInstanceConfig;
 import org.jruby.compiler.ir.IRClosure;
 import org.jruby.compiler.ir.IRExecutionScope;
 import org.jruby.compiler.ir.IRMethod;
@@ -99,9 +100,15 @@ private static void runLocalOpts(IRExecutionScope s) {
             Variable res = i.getResult();
             // System.out.println("For " + i + "; dst = " + res + "; val = " + val);
             // System.out.println("AFTER: " + i);
-            if (val != null && res != null && res != val) {
+
+            if (res != null && val != null && res != val) {
                 recordSimplification(res, val, valueMap, simplificationMap);
+            } else if (res != null && val == null) {
+                // If we didn't get a simplified value, remove any existing simplifications for the result
+                // to get rid of RAW hazards!
+                valueMap.remove(res);
             }
+
             // Optimize some core class method calls for constant values
             else if (iop.isCall()) {
                 val = null;