[Mono-bugs] [Bug 76545][Maj] New - slow execution when 'mono -O=ssapre tst.exe' and fast without optimization

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Changed by alexander.markhonko at gmail.com.

http://bugzilla.ximian.com/show_bug.cgi?id=76545

--- shadow/76545	2005-10-24 18:41:08.000000000 -0400
+++ shadow/76545.tmp.29907	2005-10-24 18:41:08.000000000 -0400
@@ -0,0 +1,76 @@
+Bug#: 76545
+Product: Mono: Runtime
+Version: 1.1
+OS: 
+OS Details: Fedora Core 4, Mono 1.1.9.2
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Major
+Component: JIT
+AssignedTo: lupus at ximian.com                            
+ReportedBy: Alexander.Markhonko at gmail.com               
+QAContact: mono-bugs at ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: slow execution when 'mono -O=ssapre tst.exe' and fast without optimization
+
+1. Compile next code:
+------------------------
+using System;
+
+
+
+namespace Test
+
+{
+	public class Tst
+	{
+		const int Count = 1000000000;
+		[STAThread]
+
+		static void Main() 
+
+		{
+
+			FloatTest(Count);
+
+		}
+
+		private static double FloatTest(int iInitVal)
+
+		{
+
+			DateTime t = DateTime.Now;
+
+			double f0 = 0;
+
+			double f1 = 123.456789;
+
+			double f2 = 98765.12345678998765432;
+
+			double f3 = 12345678943.98;
+
+			for(int i = 1; i < iInitVal; i++)
+
+				f0 = (f1 / (double)i) - f2 + (f3 * (double)i);
+
+			
+
+			Console.WriteLine(DateTime.Now - t);
+
+			return f0;	  
+
+		}
+	}
+}
+--------------------
+
+2. execute application without optimisation (mono tst.exe)
+3. execute application with 'SSA based Partial Redundancy Elimination'
+(mono -O=ssapre tst.exe)
+4. compare execution time. 
+
+On my Duron 1.3 GHz system app running about 13 seconds without
+optimization and 40 seconds with 'ssapre' optimization