[LLVMbugs] [Bug 8891] New: Early phases of backend recompute dominators too often

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=8891

           Summary: Early phases of backend recompute dominators too often
           Product: new-bugs
           Version: unspecified
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: new bugs
        AssignedTo: unassignedbugs at nondot.org
        ReportedBy: zwarich at apple.com
                CC: llvmbugs at cs.uiuc.edu


Machine Module Information
  ModulePass Manager
    FunctionPass Manager
      Preliminary module verification
      Dominator Tree Construction
      Module Verifier
      Natural Loop Information
      Loop Pass Manager
        Canonicalize natural loops
      Scalar Evolution Analysis
      Loop Pass Manager
        Induction Variable Users
        Canonicalize natural loops
        Induction Variable Users
        Loop Strength Reduction
      Lower Garbage Collection Instructions
      Remove unreachable blocks from the CFG
      Dominator Tree Construction <--- Here
      Exception handling preparation
      Optimize for code generation
      Insert stack protectors
      Preliminary module verification
      Dominator Tree Construction <--- Here
      Module Verifier

The last dominator tree computation should be easy to get rid of, since
DwarfEHPrepare already preserves dominators, CodeGenPrepare only messes with
blocks that have a single successor, and StackProtector only needs to be
concerned with the two blocks that it adds (which both have the same idom).

The one before it might not be so easy, but "UnreachableBlockElim" is entirely
dominator based, so it won't be the problem.

-- 
Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.