Skip to content

GitLab

  • Projects
  • Groups
  • Snippets
  • Help
    • Loading...
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
  • Sign in / Register
GHC
GHC
  • Project overview
    • Project overview
    • Details
    • Activity
    • Releases
  • Repository
    • Repository
    • Files
    • Commits
    • Branches
    • Tags
    • Contributors
    • Graph
    • Compare
    • Locked Files
  • Issues 4,273
    • Issues 4,273
    • List
    • Boards
    • Labels
    • Service Desk
    • Milestones
    • Iterations
  • Merge Requests 413
    • Merge Requests 413
  • Requirements
    • Requirements
    • List
  • CI / CD
    • CI / CD
    • Pipelines
    • Jobs
    • Schedules
  • Security & Compliance
    • Security & Compliance
    • Dependency List
    • License Compliance
  • Operations
    • Operations
    • Incidents
    • Environments
  • Analytics
    • Analytics
    • CI / CD
    • Code Review
    • Insights
    • Issue
    • Repository
    • Value Stream
  • Wiki
    • Wiki
  • Snippets
    • Snippets
  • Members
    • Members
  • Collapse sidebar
  • Activity
  • Graph
  • Create a new issue
  • Jobs
  • Commits
  • Issue Boards
  • Glasgow Haskell Compiler
  • GHCGHC
  • Issues
  • #14982

Closed
Open
Opened Mar 28, 2018 by Thomas Main DuBuisson@tommdReporter

LLVM default -mcpu setting inhibits customization

With GHC 8.4.1 we are now passing a default -mcpu selection to llvm. This default is passed regardless of any explicit command line option such as -optlc=-mcpu=native. If/when the user explicitly specifies the architecture we now get a failed build. The error message from LLVM is:

llc: for the -mcpu option: may only occur zero or one times!
`llc' failed in phase `LLVM Compiler'. (Exit code: 1)

This is when compiling with GHC 8.4.1 as such:

{{{ ghc-8.4.1 -fforce-recomp -fllvm -optlc=-mcpu=native -O2 tt.hs }}

I suggest we either check for a user option of mcpu before adding the default or revert this behavior and allow llvm to take it's (optimistic and less portable) default.

Trac metadata
Trac field Value
Version 8.4.1
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler (LLVM)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture
Assignee
Assign to
8.4.2
Milestone
8.4.2 (Past due)
Assign milestone
Time tracking
None
Due date
None
Reference: ghc/ghc#14982