Landing: cf6fe3baf828

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Project / Subsystem

gcc / gcc/fortran

Date

2026-06-08

Author

Paul Thomas

Commit

cf6fe3baf828c3e6cbb4b1898ff702030ae06d5c

Source

github

Perf win

Yes

Breaking

View on GitHub →

All attributes

project: gcc
subsystem: gcc/fortran
patch_id: —
commit_hash: cf6fe3baf828c3e6cbb4b1898ff702030ae06d5c
source_type: github
headline: Fortran: Prevent unnecessary mallocs and frees for parameterized derived types
tldr: GCC's Fortran front end now avoids unnecessary memory allocations and deallocations for parameterized derived types.
author: Paul Thomas
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • fortran
• optimization
• memory-management
• pdt
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/cf6fe3baf828c3e6cbb4b1898ff702030ae06d5c
date: 2026-06-08T00:00:00.000Z

The Fortran front end in GCC has been optimized to reduce unnecessary memory allocations and deallocations when handling parameterized derived types (PDT). Specifically, if the bound expressions for array components or length expressions for character components simplify to a constant, the compiler will no longer set the pdt_array or pdt_string attributes respectively. This change prevents redundant heap operations, leading to improved performance for programs heavily using PDTs.