Merge pull request #522 from dadhi/copilot/fix-modulo-instruction-issue

Emit `rem.un` for unsigned modulo expressions

Author: dadhi

src/FastExpressionCompiler/FastExpressionCompiler.cs

@@ -5929,7 +5929,7 @@ private static bool TryEmitArithmeticOperation(Type leftType, Type rightType, Ex
                     ExpressionType.Multiply => OpCodes.Mul,
                     ExpressionType.MultiplyChecked => exprType.IsUnsigned() ? OpCodes.Mul_Ovf_Un : OpCodes.Mul_Ovf,
                     ExpressionType.Divide => OpCodes.Div,
-                    ExpressionType.Modulo => OpCodes.Rem,
+                    ExpressionType.Modulo => exprType.IsUnsigned() ? OpCodes.Rem_Un : OpCodes.Rem,
                     ExpressionType.And => OpCodes.And,
                     ExpressionType.Or => OpCodes.Or,
                     ExpressionType.ExclusiveOr => OpCodes.Xor,

test/FastExpressionCompiler.UnitTests/ArithmeticOperationsTests.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Numerics;
+using System.Reflection.Emit;
 
 #if LIGHT_EXPRESSION
 using static FastExpressionCompiler.LightExpression.Expression;
@@ -18,6 +19,7 @@ public int Run()
             Can_modulus_custom_in_Action();
             Can_add_string_and_not_string();
             Can_modulus_custom();
+            Can_modulus_with_unsigned_block_local_variable();
             Can_sum_bytes_converted_to_ints();
             Can_sum_signed_bytes_converted_to_ints();
             Can_sum_all_primitive_numeric_types_that_define_binary_operator_add();
@@ -47,7 +49,7 @@ public int Run()
             Can_calculate_arithmetic_operation_with_vectors();
             Can_add_strings();
 
-            return 29;
+            return 30;
         }
 
         public void Can_sum_bytes_converted_to_ints()
@@ -229,6 +231,31 @@ public void Can_modulus()
             Asserts.AreEqual(1, f(7, 6));
         }
 
+        public void Can_modulus_with_unsigned_block_local_variable()
+        {
+            var b = Parameter(typeof(uint), "b");
+            var a = Variable(typeof(uint), "a");
+            var expr = Lambda<Func<uint, uint>>(
+                Block(new[] { a },
+                    Assign(a, Constant(0x80000000u)),
+                    Modulo(a, b)),
+                b);
+
+            var fs = expr.CompileSys();
+            var ff = expr.CompileFast(true, CompilerFlags.EnableDelegateDebugInfo);
+
+            Asserts.AreEqual(2u, fs(3u));
+            Asserts.AreEqual(2u, ff(3u));
+            ff.AssertOpCodes(
+                OpCodes.Ldc_I4,
+                OpCodes.Stloc_0,
+                OpCodes.Ldloc_0,
+                OpCodes.Ldarg_1,
+                OpCodes.Rem_Un,
+                OpCodes.Ret
+            );
+        }
+
 
         public void Can_bit_or_1()
         {