Landing: 5d3472d4933b

← All landings

Project / Subsystem

gcc / fortran

Date

2026-04-17

Author

Paul Thomas

Commit

5d3472d4933b11c26eebcd67c9227f8ada3451ed

Source

github

Impact

5/10

Perf win

Breaking

View on GitHub →

All attributes

project: gcc
subsystem: fortran
patch_id: —
commit_hash: 5d3472d4933b11c26eebcd67c9227f8ada3451ed
source_type: github
headline: Fortran: Fix wrong result for SPREAD with ncopies < 0.
tldr: The `SPREAD` intrinsic in Fortran now correctly handles negative `ncopies` arguments, which produce a zero-sized array.
why_it_matters: The `SPREAD` intrinsic is used to replicate an array along a specified dimension, and correct handling of edge cases is important for numerical simulations.
author: Paul Thomas
impact_score: 5
impact_rationale: Fixes a bug in a Fortran intrinsic function that could lead to incorrect results.
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • fortran
• intrinsic
• array
• bugfix
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/5d3472d4933b11c26eebcd67c9227f8ada3451ed
date: 2026-04-17T00:00:00.000Z

The SPREAD intrinsic in Fortran was producing incorrect results when the ncopies argument was negative. The fix modifies the spread.m4 macro to handle the scalar source case with ncopies < 0, which should result in a zero-sized array. The generated code for various data types has been regenerated, and a new test case has been added.