[LLVMbugs] [Bug 13315] New: gcc tail merges cases that llvm doesn't

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=13315

             Bug #: 13315
           Summary: gcc tail merges cases that llvm doesn't
           Product: libraries
           Version: trunk
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Scalar Optimizations
        AssignedTo: unassignedbugs at nondot.org
        ReportedBy: rafael.espindola at gmail.com
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified


Created attachment 8864
  --> http://llvm.org/bugs/attachment.cgi?id=8864
testcase

I reduced this from a testcase where clang was spilling more than gcc. Not sure
if merging the tails would simplify the function enough to fix it.

Currently we do the merging very late, so it is easy for an optimization to
have changed the two BBs in a way that makes them hard to merge in CodeGen.

When compiling with clang the attached testcase has 3 static virtual calls,
with gcc it has 2 static (and the expected 3 dynamic ones).

-- 
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.