Landing: 7dab38c9d710

← All landings

Project / Subsystem

gcc / phiopt

Date

2026-09-03

Author

Aldy Hernandez

Commit

7dab38c9d7104ea701a60ef71837695f24aec86b

Source

github

Perf win

Breaking

View on GitHub →

All attributes

project: gcc
subsystem: phiopt
patch_id: —
commit_hash: 7dab38c9d7104ea701a60ef71837695f24aec86b
source_type: github
headline: phiopt: clear the range info of hoisted adjacent loads
tldr: Fixes incorrect range information after hoisting adjacent loads, preventing bugs in subsequent optimizations.
author: Aldy Hernandez
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• correctness
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/7dab38c9d7104ea701a60ef71837695f24aec86b
date: 2026-09-03T00:00:00.000Z

The hoist_adjacent_loads optimization in GCC moves loads from within a conditional block to its head. However, it previously retained the range information computed for those loads under the condition, leading to incorrect analysis for subsequent optimizations like range propagation. This change clears that stale range information, ensuring the optimizer uses accurate data and preventing potential bugs, especially when combined with future range analysis improvements.