ballercat/walt

Unsigned integers

Open

#120 opened on May 19, 2018

View on GitHub
 (2 comments) (2 reactions) (0 assignees)JavaScript (4,637 stars) (155 forks)batch import
enhancementhelp wantedmoderate

Description

Feature Request

Overview

Walt currently supports only signed integers and signed operations. Since WebAssembly also supports unsigned operations, it would be really neat to also have unsigned types u32 and u64. These operations should be used:

  • i32.div_u and i64.div_u (x / y)
  • i32.rem_u and i64.rem_u (x % y)
  • i32.shr_u and i64.shr_u (x >> y)
  • i32.lt_u and i64.lt_u (x < y)
  • i32.le_u and i64.le_u (x <= y)
  • i32.gt_u and i64.gt_u (x > y)
  • i32.ge_u and i64.ge_u (x >= y)
  • i64.load32_u (const x: u32 = 10; const y: u64 = x;)
  • i32.trunc_u/f32 (const x: f32 = 10; const y: u32 = x;)
  • i32.trunc_u/f64 (const x: f64 = 10; const y: u32 = x;)
  • i64.extend_u/i32 (const x: u32 = 10; const y: u64 = x;)
  • i64.trunc_u/f32 (const x: f32 = 10; const y: u64 = x;)
  • i64.trunc_u/f64 (const x: f64 = 10; const y: u64 = x;)
  • f32.convert_u/i32 (const x: u32 = 10; const y: f32 = x;)
  • f32.convert_u/i64 (const x: u64 = 10; const y: f32 = x;)
  • f64.convert_u/i32 (const x: u32 = 10; const y: f64 = x;)
  • f64.convert_u/i64 (const x: u64 = 10; const y: f64 = x;)

Example

const x: u32 = 42;
const y: u32 = 0xffffffff;
const z: i32 = x < y; // should be 1

Contributor guide

Tech stack
javascriptwasm
Domain
tooling
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
WebAssembly basicsWalt syntaxCompiler fundamentals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35
Research direction
Start by examining the existing implementation of signed integer types in the Walt compiler, particularly how i32 and i64 are parsed and code generated. Look for files related to type checking and code generation for integer operations. Study the WebAssembly specification for unsigned operations to understand the differences. Then implement the new unsigned integer types and operations following the pattern of signed ones.