adding floating point conversions

lang/README.md

@@ -277,6 +277,9 @@ main := fn(): uint {
 	same_type_as_byte := @as(@TypeOf(byte), 30)
 	wide_uint := @as(u32, 40)
 	truncated_uint := @as(u8, @intcast(wide_uint))
+	widened_float := @as(f64, @floatcast(1.))
+	int_from_float := @as(int, @fti(1.))
+	float_from_int := @as(f64, @itf(@as(int, 1)))
 	size_of_Type_in_bytes := @sizeof(foo.Type)
 	align_of_Type_in_bytes := @alignof(foo.Type)
 	hardcoded_pointer := @as(^u8, @bitcast(10))

lang/src/lexer.rs

@@ -257,9 +257,16 @@ impl TokenKind {
             && self.precedence() != Self::Eof.precedence()
     }
 
-    pub fn apply_unop(&self, value: i64) -> i64 {
+    pub fn apply_unop(&self, value: i64, float: bool) -> i64 {
         match self {
+            Self::Sub if float => (-f64::from_bits(value as _)).to_bits() as _,
             Self::Sub => value.wrapping_neg(),
+            Self::Float if float => value,
+            Self::Float => (value as f64).to_bits() as _,
+            Self::Number => {
+                debug_assert!(float);
+                f64::from_bits(value as _).to_bits() as _
+            }
             s => todo!("{s}"),
         }
     }

lang/src/son.rs

@@ -792,10 +792,14 @@ impl Nodes {
                 let &[ctrl, oper] = self[target].inputs.as_slice() else { unreachable!() };
                 let ty = self[target].ty;
 
+                let is_float = self[oper].ty.is_float();
+
                 if let K::CInt { value } = self[oper].kind {
-                    return Some(
-                        self.new_node(ty, K::CInt { value: op.apply_unop(value) }, [ctrl]),
-                    );
+                    return Some(self.new_node(
+                        ty,
+                        K::CInt { value: op.apply_unop(value, is_float) },
+                        [ctrl],
+                    ));
                 }
             }
             K::If => {
@@ -2649,6 +2653,79 @@ impl<'a> Codegen<'a> {
                     Some(val.ty(ty))
                 }
             }
+            Expr::Directive { pos, name: "floatcast", args: [expr] } => {
+                let val = self.expr(expr)?;
+
+                if !val.ty.is_float() {
+                    self.report(
+                        expr.pos(),
+                        fa!(
+                            "only floats can be truncated ('{}' is not a float)",
+                            self.ty_display(val.ty)
+                        ),
+                    );
+                    return Value::NEVER;
+                }
+
+                inference!(ty, ctx, self, pos, "float", "@as(<floaty>, @floatcast(<expr>))");
+
+                if !ty.is_float() {
+                    self.report(
+                        expr.pos(),
+                        fa!(
+                            "floatcast is inferred to output '{}', which is not a float",
+                            self.ty_display(ty)
+                        ),
+                    );
+                }
+
+                if self.tys.size_of(val.ty) < self.tys.size_of(ty) {
+                    Some(
+                        self.ci
+                            .nodes
+                            .new_node_lit(ty, Kind::UnOp { op: TokenKind::Float }, [VOID, val.id]),
+                    )
+                } else {
+                    Some(val.ty(ty))
+                }
+            }
+            Expr::Directive { name: "fti", args: [expr], .. } => {
+                let val = self.expr(expr)?;
+
+                let ret_ty = match val.ty {
+                    ty::Id::F64 => ty::Id::INT,
+                    ty::Id::F32 => ty::Id::I32,
+                    _ => {
+                        self.report(
+                            expr.pos(),
+                            fa!("expected float ('{}' is not a float)", self.ty_display(val.ty)),
+                        );
+                        return Value::NEVER;
+                    }
+                };
+
+                Some(
+                    self.ci
+                        .nodes
+                        .new_node_lit(ret_ty, Kind::UnOp { op: TokenKind::Number }, [VOID, val.id]),
+                )
+            }
+            Expr::Directive { name: "itf", args: [expr], .. } => {
+                let mut val = self.expr(expr)?;
+
+                let (ret_ty, expected) = match val.ty.simple_size().unwrap() {
+                    8 => (ty::Id::F64, ty::Id::INT),
+                    _ => (ty::Id::F32, ty::Id::I32),
+                };
+
+                self.assert_ty(expr.pos(), &mut val, expected, "converted integer");
+
+                Some(
+                    self.ci
+                        .nodes
+                        .new_node_lit(ret_ty, Kind::UnOp { op: TokenKind::Float }, [VOID, val.id]),
+                )
+            }
             Expr::Directive { name: "as", args: [ty, expr], .. } => {
                 let ty = self.ty(ty);
                 let ctx = Ctx::default().with_ty(ty);

lang/src/son/hbvm.rs

@@ -323,7 +323,9 @@ impl ItemCtx {
                         _ => instrs::li64(atr(allocs[0]), value as _),
                     }),
                     Kind::UnOp { op } => {
-                        let op = op.unop().expect("TODO: unary operator not supported");
+                        let op = op
+                            .unop(node.ty, fuc.nodes[node.inputs[1]].ty)
+                            .expect("TODO: unary operator not supported");
                         let &[dst, oper] = allocs else { unreachable!() };
                         self.emit(op(atr(dst), atr(oper)));
                     }
@@ -1332,9 +1334,19 @@ impl TokenKind {
         Some(ops[size.ilog2() as usize])
     }
 
-    pub fn unop(&self) -> Option<fn(u8, u8) -> EncodedInstr> {
+    pub fn unop(&self, dst: ty::Id, src: ty::Id) -> Option<fn(u8, u8) -> EncodedInstr> {
+        let src_idx = src.simple_size().unwrap().ilog2() as usize - 2;
         Some(match self {
             Self::Sub => instrs::neg,
+            Self::Float if dst.is_float() && src.is_integer() => {
+                [instrs::itf32, instrs::itf64][src_idx]
+            }
+            Self::Number if src.is_float() && dst.is_integer() => {
+                [|a, b| instrs::fti32(a, b, 1), |a, b| instrs::fti64(a, b, 1)][src_idx]
+            }
+            Self::Float if dst.is_float() && src.is_float() => {
+                [instrs::fc32t64, |a, b| instrs::fc64t32(a, b, 1)][src_idx]
+            }
             _ => return None,
         })
     }