Exclude whole numbers from "constant unfolding" for floating point literals.

ICSharpCode.Decompiler.Tests/TestCases/Pretty/WellKnownConstants.cs

@@ -67,6 +67,11 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 		public const decimal DecimalMaxValue = decimal.MaxValue;
 		public const decimal DecimalMinValue = decimal.MinValue;
 
+		public const float Float_One = 1f;
+		public const double Double_One = 1.0;
+		public const float Float_Two = 2f;
+		public const double Double_Two = 2.0;
+
 		public const float Float_PI = (float)Math.PI;
 		public const float Float_HalfOfPI = (float)Math.PI / 2f;
 		public const float Float_QuarterOfPI = (float)Math.PI / 4f;

ICSharpCode.Decompiler.Tests/TestCases/Pretty/WellKnownConstants.il

@@ -78,6 +78,10 @@
                                                                                                   uint32,
                                                                                                   uint32) = ( 01 00 00 80 FF FF FF FF FF FF FF FF FF FF FF FF 
                                                                                                               00 00 ) 
+  .field public static literal float32 Float_One = float32(1.)
+  .field public static literal float64 Double_One = float64(1.)
+  .field public static literal float32 Float_Two = float32(2.)
+  .field public static literal float64 Double_Two = float64(2.)
   .field public static literal float32 Float_PI = float32(3.1415927)
   .field public static literal float32 Float_HalfOfPI = float32(1.5707964)
   .field public static literal float32 Float_QuarterOfPI = float32(0.78539819)

ICSharpCode.Decompiler.Tests/TestCases/Pretty/WellKnownConstants.opt.il

@@ -78,6 +78,10 @@
                                                                                                   uint32,
                                                                                                   uint32) = ( 01 00 00 80 FF FF FF FF FF FF FF FF FF FF FF FF 
                                                                                                               00 00 ) 
+  .field public static literal float32 Float_One = float32(1.)
+  .field public static literal float64 Double_One = float64(1.)
+  .field public static literal float32 Float_Two = float32(2.)
+  .field public static literal float64 Double_Two = float64(2.)
   .field public static literal float32 Float_PI = float32(3.1415927)
   .field public static literal float32 Float_HalfOfPI = float32(1.5707964)
   .field public static literal float32 Float_QuarterOfPI = float32(0.78539819)

ICSharpCode.Decompiler.Tests/TestCases/Pretty/WellKnownConstants.opt.roslyn.il

@@ -82,6 +82,10 @@
                                                                                                   uint32,
                                                                                                   uint32) = ( 01 00 00 80 FF FF FF FF FF FF FF FF FF FF FF FF 
                                                                                                               00 00 ) 
+  .field public static literal float32 Float_One = float32(1.)
+  .field public static literal float64 Double_One = float64(1.)
+  .field public static literal float32 Float_Two = float32(2.)
+  .field public static literal float64 Double_Two = float64(2.)
   .field public static literal float32 Float_PI = float32(3.1415927)
   .field public static literal float32 Float_HalfOfPI = float32(1.5707964)
   .field public static literal float32 Float_QuarterOfPI = float32(0.78539819)

ICSharpCode.Decompiler.Tests/TestCases/Pretty/WellKnownConstants.roslyn.il

@@ -82,6 +82,10 @@
                                                                                                   uint32,
                                                                                                   uint32) = ( 01 00 00 80 FF FF FF FF FF FF FF FF FF FF FF FF 
                                                                                                               00 00 ) 
+  .field public static literal float32 Float_One = float32(1.)
+  .field public static literal float64 Double_One = float64(1.)
+  .field public static literal float32 Float_Two = float32(2.)
+  .field public static literal float64 Double_Two = float64(2.)
   .field public static literal float32 Float_PI = float32(3.1415927)
   .field public static literal float32 Float_HalfOfPI = float32(1.5707964)
   .field public static literal float32 Float_QuarterOfPI = float32(0.78539819)

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -2270,9 +2270,14 @@ namespace ICSharpCode.Decompiler.CSharp
 					container.Peek().Elements.Add(aie);
 					container.Push(aie);
 				}
-				astBuilder.UseSpecialConstants = !type.IsCSharpPrimitiveIntegerType();
-				var val = Translate(value, typeHint: type).ConvertTo(type, this, allowImplicitConversion: true);
-				astBuilder.UseSpecialConstants = true;
+				TranslatedExpression val;
+				var old = astBuilder.UseSpecialConstants;
+				try {
+					astBuilder.UseSpecialConstants = !type.IsCSharpPrimitiveIntegerType();
+					val = Translate(value, typeHint: type).ConvertTo(type, this, allowImplicitConversion: true);
+				} finally {
+					astBuilder.UseSpecialConstants = old;
+				}
 				container.Peek().Elements.Add(val);
 				elementResolveResults.Add(val.ResolveResult);
 				while (container.Count > 0 && container.Peek().Elements.Count == dimensionSizes[container.Count - 1]) {

ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs

@@ -937,11 +937,11 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			Expression expr = null;
 
 			if (isDouble) {
-				if ((double)constantValue >= int.MaxValue || (double)constantValue <= int.MinValue) {
+				if (Math.Floor((double)constantValue) == (double)constantValue) {
 					expr = new PrimitiveExpression(constantValue);
 				}
 			} else {
-				if ((float)constantValue >= int.MaxValue || (float)constantValue <= int.MinValue) {
+				if (Math.Floor((float)constantValue) == (float)constantValue) {
 					expr = new PrimitiveExpression(constantValue);
 				}
 			}