Revert "remove return type for deduced int"

This reverts commit 66a4b20bda.

internal/shader/expr.go

@@ -124,8 +124,11 @@ func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, mar
 
 				// If left is untyped const
 				if lhst.Main == shaderir.None && lhs[0].Const != nil {
+					if rhs[0].Const != nil {
 						lhst = shaderir.Type{Main: shaderir.Int}
-					// Left should be implicitly converted to the type it would assume if the shift expression were replaced by its left operand alone.
+					} else {
+						lhst = shaderir.Type{Main: shaderir.DeducedInt}
+					}
 				}
 			}
 		} else {

internal/shader/stmt.go

@@ -514,6 +514,9 @@ func (cs *compileState) assign(block *block, fname string, pos token.Pos, lhs, r
 					return nil, false
 				}
 				t := ts[0]
+				if t.Main == shaderir.DeducedInt {
+					cs.addError(pos, "invalid operation: shifted operand 1 (type float) must be integer")
+				}
 				if t.Main == shaderir.None {
 					t = toDefaultType(r[0].Const)
 				}
@@ -705,6 +708,9 @@ func canAssign(lt *shaderir.Type, rt *shaderir.Type, rc gconstant.Value) bool {
 	if lt.Equal(rt) {
 		return true
 	}
+	if lt.Main == shaderir.Int && rt.Main == shaderir.DeducedInt {
+		return true
+	}
 
 	if rc == nil {
 		return false

internal/shader/syntax_test.go

@@ -1324,16 +1324,16 @@ func TestSyntaxOperatorShift(t *testing.T) {
 		// {stmt: "s := 1; var a float = float(1.0 << s); _ = a", err: true},
 		// {stmt: "s := 1; var a int = int(1 << s); _ = a", err: false},
 		// {stmt: "s := 1; var a int = int(1.0 << s); _ = a", err: false},
-		// {stmt: "s := 1; a := 1 << s; _ = a", err: false},
-		// {stmt: "s := 1; a := 1.0 << s; _ = a", err: true},
-		// {stmt: "s := 1; a := int(1.0 << s); _ = a", err: false},
-		// {stmt: "s := 1; var a float = float(1.0 << s); _ = a", err: true},
-		// {stmt: "s := 1; var a float = 1.0 << s; _ = a", err: true},
-		// {stmt: "s := 1; var a float = 1 << s; _ = a", err: true},
-		// {stmt: "s := 1; var a int = 1.0 << s; _ = a", err: false},
-		// {stmt: "s := 1; var a int = 1 << s; _ = a", err: false},
 
+		{stmt: "s := 1; a := 1 << s; _ = a", err: false},
+		{stmt: "s := 1; a := 1.0 << s; _ = a", err: true},
+		{stmt: "s := 1; a := int(1.0 << s); _ = a", err: false},
 		{stmt: "var a float = 1.0 << 2.0; _ = a", err: false},
+		{stmt: "s := 1; var a float = float(1.0 << s); _ = a", err: true},
+		{stmt: "s := 1; var a float = 1.0 << s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 << s; _ = a", err: true},
+		{stmt: "s := 1; var a int = 1.0 << s; _ = a", err: false},
+		{stmt: "s := 1; var a int = 1 << s; _ = a", err: false},
 		{stmt: "var a int = 1.0 << 2; _ = a", err: false},
 		{stmt: "var a float = 1.0 << 2; _ = a", err: false},
 		{stmt: "var a = 1.0 << 2; _ = a", err: false},
@@ -1363,7 +1363,12 @@ func TestSyntaxOperatorShift(t *testing.T) {
 		{stmt: "a := vec3(1) << ivec2(2); _ = a", err: true},
 		{stmt: "a := ivec2(1) << vec3(2); _ = a", err: true},
 
-		{stmt: "var a float = 1.0 >> 2.0; _ = a", err: false},
+		{stmt: "s := 1; var a float = float(1.0 >> s); _ = a", err: true},
+		{stmt: "s := 1; var a int = int(1.0 >> s); _ = a", err: false},
+		{stmt: "s := 1; var a float = 1.0 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a int = 1.0 >> s; _ = a", err: false},
+		{stmt: "s := 1; var a int = 1 >> s; _ = a", err: false},
 		{stmt: "var a int = 1.0 >> 2; _ = a", err: false},
 		{stmt: "var a float = 1.0 >> 2; _ = a", err: false},
 		{stmt: "var a = 1.0 >> 2; _ = a", err: false},

internal/shader/type.go

@@ -165,7 +165,7 @@ func checkArgsForIntBuiltinFunc(args []shaderir.Expr, argts []shaderir.Type) err
 	if len(args) != 1 {
 		return fmt.Errorf("number of int's arguments must be 1 but %d", len(args))
 	}
-	if argts[0].Main == shaderir.Int || argts[0].Main == shaderir.Float {
+	if argts[0].Main == shaderir.Int || argts[0].Main == shaderir.Float || argts[0].Main == shaderir.DeducedInt {
 		return nil
 	}
 	if args[0].Const != nil && gconstant.ToInt(args[0].Const).Kind() != gconstant.Unknown {

internal/shaderir/check.go

@@ -145,7 +145,7 @@ func TypeFromBinaryOp(op Op, lhst, rhst Type, lhsConst, rhsConst constant.Value)
 	}
 
 	if op == LeftShift || op == RightShift {
-		if lhst.Main == Int && rhst.Main == Int {
+		if (lhst.Main == Int || lhst.Main == DeducedInt) && rhst.Main == Int {
 			return Type{Main: lhst.Main}, true
 		}
 		if lhst.IsIntVector() && rhst.Main == Int {

internal/shaderir/type.go

@@ -180,6 +180,7 @@ const (
 	Texture
 	Array
 	Struct
+	DeducedInt
 )
 
 func descendantLocalVars(block, target *Block) ([]Type, bool) {