From 9d1246d799419a8e7d96302c5787ce252e86b68d Mon Sep 17 00:00:00 2001
From: Gene Novark <gnovark@gmail.com>
Date: Fri, 4 Jul 2014 15:01:11 -0400
Subject: Fix asymptotic performance issues in live variables analysis.

Fix possibly-exponential runtime for DFS graph searches.
Improve DFA fixpoint algorithm to correctly compute worklist
of only changed nodes for each iteration.

Added test that takes > 2 minutes to compile without these
improvements.
---
 .../scala/scala/async/run/ifelse1/IfElse1.scala    | 77 ++++++++++++++++++++++
 1 file changed, 77 insertions(+)

(limited to 'src/test/scala/scala/async/run/ifelse1/IfElse1.scala')

diff --git a/src/test/scala/scala/async/run/ifelse1/IfElse1.scala b/src/test/scala/scala/async/run/ifelse1/IfElse1.scala
index 587aaac..6cbe910 100644
--- a/src/test/scala/scala/async/run/ifelse1/IfElse1.scala
+++ b/src/test/scala/scala/async/run/ifelse1/IfElse1.scala
@@ -87,6 +87,75 @@ class TestIfElse1Class {
     }
     z
   }
+
+  def pred: Future[Boolean] = async(true) 
+
+  def m5: Future[Boolean] = async {
+    if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(if(await(pred))
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false)
+      await(pred)
+    else
+      false
+  }
 }
 
 class IfElse1Spec {
@@ -124,4 +193,12 @@ class IfElse1Spec {
     val res = Await.result(fut, 2 seconds)
     res mustBe (14)
   }
+
+  @Test
+  def `await in deeply-nested if-else conditions`() {
+    val o = new TestIfElse1Class
+    val fut = o.m5
+    val res = Await.result(fut, 2 seconds)
+    res mustBe true
+  }
 }
-- 
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