Description

MaxGraey

opened on Apr 10, 2026

Issue body actions

AssemblyScript currently uses a pretty old Grisu2-based algorithm for f32/f64 to string conversion. Will be great to rewrite this using Zmij xjb, which is a newer shortest-roundtrip algorithm and should be much faster and probably more precise in some rare cases. SIMD should be optional.

Current implementation: https://github.com/AssemblyScript/assemblyscript/blob/main/std/assembly/util/number.ts#L729
Tests: https://github.com/AssemblyScript/assemblyscript/blob/main/tests/compiler/std/string.ts#L736

C++ Reference: https://github.com/vitaut/zmij
Rust port: https://github.com/dtolnay/zmij
C++ Reference: https://github.com/xjb714/xjb

Reacted by Jairus

Reacted by Abdiel Lopez and Jairus

Activity

1. MaxGraey

   added

   enhancement

   performance

   standard library

   on Apr 10, 2026
2. MaxGraey

   changed the title [-]Replace Grisu2 with Dragonbox for float-to-string conversion[/-] [+]Replace Grisu2 with Zmij for float-to-string conversion[/+] on Apr 10, 2026
3. MaxGraey

   changed the title [-]Replace Grisu2 with Zmij for float-to-string conversion[/-] [+][Task] Replace Grisu2 with Zmij for float-to-string conversion[/+] on Apr 11, 2026
4. JairusSW

   changed the title [-][Task] Replace Grisu2 with Zmij for float-to-string conversion[/-] [+][Task] Replace Grisu2 with Xjbfor float-to-string conversion[/+] on Oct 31, 2026
5. JairusSW

   changed the title [-][Task] Replace Grisu2 with Xjbfor float-to-string conversion[/-] [+][Task] Replace Grisu2 with Xjb for float-to-string conversion[/+] on Oct 31, 2026

Issue actions