[Mono-bugs] [Bug 60673][Wis] New - -O=loop sometimes adds padding in wrong places

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Changed by bmaurer@users.sf.net.

http://bugzilla.ximian.com/show_bug.cgi?id=60673

--- shadow/60673	2004-06-23 21:29:32.000000000 -0400
+++ shadow/60673.tmp.20018	2004-06-23 21:29:32.000000000 -0400
@@ -0,0 +1,68 @@
+Bug#: 60673
+Product: Mono: Runtime
+Version: unspecified
+OS: 
+OS Details: 
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Wishlist
+Component: misc
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: bmaurer@users.sf.net               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: -O=loop sometimes adds padding in wrong places
+
+Consider this code:
+
+using System;
+class T {
+	static void Main () {
+		int i = Environment.TickCount;
+		new T ().X ();
+		Console.WriteLine (Environment.TickCount - i);
+	}
+	
+	void X () {
+		int i = 0;
+		while (
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000 &&
+			i < 50000000) i ++;
+	}
+}
+
+We generate assembly like:
+
+  11:	81 ff 80 f0 fa 02    	cmp    edi,0x2faf080
+  17:	0f 8d 27 01 00 00    	jge    144 <T_X+0x144>
+  1d:	8d 6d 00             	lea    ebp,[ebp]
+  20:	81 ff 80 f0 fa 02    	cmp    edi,0x2faf080
+  26:	0f 8d 18 01 00 00    	jge    144 <T_X+0x144>
+  2c:	8d 64 24 00          	lea    esp,[esp]
+  30:	81 ff 80 f0 fa 02    	cmp    edi,0x2faf080
+
+the lea instructions are padding, which are trying to align loops. However,
+ alignment should not be added.