Simon Jakobi pushed to branch wip/sjakobi/T25450-march-native at Glasgow Haskell Compiler / GHC

Commits:

• a0369c82
  by Simon Jakobi at 2026-06-02T13:59:36+02:00

  Mark -march=native as expected-undocumented for the flag linter
  
  --show-options emits the full token "-march=native", but compare-flags.py
  strips documented flags at "=", so the ghc-flag directive reduces to
  "-march" and never matches. List the full token here, consistent with
  other value-variant flags such as -rtsopts=all and -fdiagnostics-color=always.
  
  Issue reported in #27321.
  
  Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
  

• d4cf9ff9
  by Simon Jakobi at 2026-06-02T14:03:20+02:00

  Remove redundant Data.Bits import in CpuFeatures
  
  testBit is already in scope via GHC.Prelude, which re-exports all of
  Data.Bits. The explicit import tripped -Werror=unused-imports.
  
  Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
  

2 changed files:

• compiler/GHC/Driver/CpuFeatures.hs
• docs/users_guide/expected-undocumented-flags.txt

Changes:

 import GHC.Prelude

-import Data.Bits (testBit)

 import Data.Word (Word64)

 import System.IO.Unsafe (unsafePerformIO)

 -instantiated-with

 -keep-hi-file

 -keep-o-file

+-march=native

 -n

 -no-keep-hi-file

 -no-keep-o-file