Support for larger numbers (i128, u64, i128) as well as nightly-only floats f16/f128 and greater support for different number types in bitwise and normal operations.

All backed up and verified by an expansion to the ops test.

Author: IntegralPilot

Cargo.lock

@@ -4,6 +4,9 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+half = "2.6.0"
+num-bigint = "0.4.6"
+num-traits = "0.2.19"
 regex = "1.11.1"
 ristretto_classfile = { version = "0.16.0" }
 serde = { version = "1.0.219", features = ["derive"] }
@@ -14,4 +17,4 @@ sha2 = "0.10.8"
 crate-type = ["dylib"]
 
 [package.metadata.rust-analyzer] 
-rustc_private=true
+rustc_private=true

Cargo.toml

@@ -29,20 +29,20 @@ This backend currently supports a subset of Rust features:
 
 *   ✅ Compiling minimal `no_std` & `no_core` Rust programs (like an empty `main`) using the `jvm-unknown-unknown` target.
 *   ✅ Compiling simple programs using basic `core` features (like other tests) using the host target but this codegen backend to produce JVM bytecode.
-*   ✅ Basic integer arithmetic operations on all types of numbers:
+*   ✅ Basic integer arithmetic operations on all types of numbers including floats:
     *   Addition (`+`), Subtraction (`-`), Multiplication (`*`), Division (`/`), Remainder (`%`).
-    *   Checked addition, subtraction and multiplication returning `(result, overflowed_bool)` tuples (occurs in debug mode)
-*   ✅ Comparisons (`==`, `!=`, `<`, `<=`, `>`, `>=`).
-*   ✅ Bitwise operations (`&`, `|`, `^`, `<<`, `>>`).
-*   ✅ Logical operations (`&&`, `||`, `!`), support for `if` (and `else if`/`else`) and `match` statements.
+    *   Checked addition, subtraction and multiplication returning `(result, overflowed_bool)` tuples (`rustc` requests this in debug mode even for normal operations to panic on overflow).
+*   ✅ Comparisons between all number types (`==`, `!=`, `<`, `<=`, `>`, `>=`).
+*   ✅ Bitwise operations on all numbers (`&`, `|`, `^`, `<<`, `>>`).
+*   ✅ Logical operations(`&&`, `||`, `!`), support for `if` (and `else if`/`else`) and `match` statements.
 *   ✅ Unary operations (`-`, `!`).
 *   ✅ Type casting (e.g., `as` operator).
-*   ✅ Support for all primitive types.
+*   ✅ Support for all Rust primitive types.
 *   ✅ Calling other functions (including recursion).
 *   ✅ Loops such as `for`, `while`, and `loop`.
 *   ✅ Variable assignment including subfield and array index assignment, including nesting.
 *   ✅ Arrays and slices, including inserting, accessing and mutating at a given index (supporting nesting).
-*   ✅ Floats (`f32`, `f64`).
+*   ✅ Floats (`f16`, `f32`, `f64`, `f128`) and their operations.
 *   ✅ Structs, Tuples and Enums (including traditional C-like enums but also Rust-like enums with anonymous structs and tuples in them) including nested access/setting/mutation of fields and array indices within these.
 *   ✅ Generating executable `.jar` files for binary crates.
 

Readme.md

@@ -76,6 +76,16 @@ public object Core {
             return false
         }
 
+        // Special handling for floating point types
+        // Java's .equals() method does not handle NaN correctly (NaN == NaN which is the opposite of what Rust expects)
+        if ((value1 is Double || value1 is Float) && (value2 is Double || value2 is Float)) {
+            val d1 = if (value1 is Float) value1.toDouble() else value1 as Double
+            val d2 = if (value2 is Float) value2.toDouble() else value2 as Double
+            // Direct comparison using IEEE 754 rules (NaN != NaN)
+            @Suppress("FloatingPointLiteralComparison") // We WANT this specific comparison
+            return d1 == d2
+        }
+
         // 2. Handle common Kotlin/Java types where '==' gives value equality
         //    or specific content checks are needed.
         val class1 = value1::class.java

library/src/main/kotlin/org/rustlang/core/Core.kt

@@ -1,6 +1,8 @@
 #![feature(alloc_error_hook)]
 #![feature(box_patterns)]
 #![feature(rustc_private)]
+#![feature(f16)]
+#![feature(f128)]
 #![warn(clippy::pedantic)]
 #![allow(clippy::cast_possible_truncation)]
 #![allow(clippy::cast_sign_loss)]