[llvm-commits] Question about /llvm/trunk/lib/CodeGen/MachineScheduler.cpp

[Sergei Larin]

Andrew, 

  This is something between a bug report and a question. I do not provide
enough context to reproduce the failure, but hope it is fresh enough in your
memory :) 

In lib/CodeGen/MachineScheduler.cpp

In bool MachineScheduler::runOnMachineFunction(MachineFunction &mf) {}

While iterating over following MBB, for the following fragment
...
BB#6: derived from LLVM BB %sw.bb6, ADDRESS TAKEN
    Predecessors according to CFG: BB#1
        %vreg10<def> = TFRI 1; IntRegs:%vreg10
        STrib %vreg1<kill>, 0, %vreg10<kill>; mem:ST1[%Enum_Ref_Par]
IntRegs:%vreg1,%vreg10
        JMP <BB#8>
    Successors according to CFG: BB#8

BB#7: derived from LLVM BB %sw.bb7, ADDRESS TAKEN
    Predecessors according to CFG: BB#1
        %vreg9<def> = TFRI 2; IntRegs:%vreg9
        STrib %vreg1<kill>, 0, %vreg9<kill>; mem:ST1[%Enum_Ref_Par]
IntRegs:%vreg1,%vreg9
    Successors according to CFG: BB#8

BB#8: derived from LLVM BB %sw.epilog, ADDRESS TAKEN
    Predecessors according to CFG: BB#0 BB#1 BB#7 BB#6 BB#5 BB#4 BB#2
        JMPR %PC<imp-def,dead>, %R31<imp-use>, %R0<imp-use,undef>
...

BB#7 seems to cause a problem when iterating over it with RegionEnd pointing
somewhere wrong. Am I breaking some implicit assumption in BB formation?
Want MBB->end() suppose to return for the BB#7?

*** Final schedule ***

MachineScheduling Proc_6:BB#7
  From: %vreg9<def> = TFRI 2; IntRegs:%vreg9
    To:
Program received signal SIGSEGV, Segmentation fault.
0x0000000001a0c814 in llvm::MachineOperand::isReg (this=0x7) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/include/llvm/CodeGen/
MachineOperand.h:204
204       bool isReg() const { return OpKind == MO_Register; }
(gdb) bt
#0  0x0000000001a0c814 in llvm::MachineOperand::isReg (this=0x7) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/include/llvm/CodeGen/
MachineOperand.h:204
#1  0x00000000021ca720 in llvm::MachineInstr::print (this=0x3e2c9f0, OS=...,
TM=0x0) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/CodeGen/MachineIn
str.cpp:1462
#2  0x0000000001a970fe in llvm::operator<< (OS=..., MI=...) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/include/llvm/CodeGen/
MachineInstr.h:934
#3  0x00000000022e4c18 in (anonymous
namespace)::MachineScheduler::runOnMachineFunction (this=0x3dcc1c0, mf=...)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/CodeGen/MachineSc
heduler.cpp:297
#4  0x00000000021c41e5 in llvm::MachineFunctionPass::runOnFunction
(this=0x3dcc1c0, F=...) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/CodeGen/MachineFu
nctionPass.cpp:33
#5  0x0000000002789db6 in llvm::FPPassManager::runOnFunction
(this=0x3dcb820, F=...) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/VMCore/PassManage
r.cpp:1498
#6  0x000000000278a001 in llvm::FPPassManager::runOnModule (this=0x3dcb820,
M=...) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/VMCore/PassManage
r.cpp:1520
#7  0x000000000278a344 in llvm::MPPassManager::runOnModule (this=0x3dc8ec0,
M=...) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/VMCore/PassManage
r.cpp:1574
#8  0x000000000278a85a in llvm::PassManagerImpl::run (this=0x3dc8b70, M=...)
at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/VMCore/PassManage
r.cpp:1658
#9  0x000000000278ab55 in llvm::PassManager::run (this=0x3d7f140, M=...) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/lib/VMCore/PassManage
r.cpp:1687
#10 0x0000000000c9488d in (anonymous
namespace)::EmitAssemblyHelper::EmitAssembly (this=0x7fffffffa2e0,
Action=clang::Backend_EmitAssembly, OS=0x3d13660)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/CodeG
en/BackendUtil.cpp:497
#11 0x0000000000c94968 in clang::EmitBackendOutput (Diags=..., CGOpts=...,
TOpts=..., LOpts=..., M=0x3d1a3c0, Action=clang::Backend_EmitAssembly,
OS=0x3d13660)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/CodeG
en/BackendUtil.cpp:509
#12 0x0000000000c9042c in clang::BackendConsumer::HandleTranslationUnit
(this=0x3d123a0, C=...)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/CodeG
en/CodeGenAction.cpp:155
#13 0x0000000000e3cf61 in clang::ParseAST (S=..., PrintStats=false) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/Parse
/ParseAST.cpp:110
#14 0x0000000000b00725 in clang::ASTFrontendAction::ExecuteAction
(this=0x3cf1740) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/Front
end/FrontendAction.cpp:414
#15 0x0000000000c8ef9c in clang::CodeGenAction::ExecuteAction
(this=0x3cf1740) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/CodeG
en/CodeGenAction.cpp:407
#16 0x0000000000b00377 in clang::FrontendAction::Execute (this=0x3cf1740) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/Front
end/FrontendAction.cpp:334
#17 0x0000000000ad8e63 in clang::CompilerInstance::ExecuteAction
(this=0x3ced2d0, Act=...)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/Front
end/CompilerInstance.cpp:653
#18 0x0000000000aaa8e4 in clang::ExecuteCompilerInvocation (Clang=0x3ced2d0)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/lib/Front
endTool/ExecuteCompilerInvocation.cpp:175
#19 0x0000000000a99618 in cc1_main (ArgBegin=0x7fffffffaf10,
ArgEnd=0x7fffffffb108, Argv0=0x3cebaf8
"/prj/qct/sunray-austin/scratch/slarin/qdsp6_hex/bin/qc/bin/clang",
MainAddr=0xaa4654)
    at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/tools/dri
ver/cc1_main.cpp:165
#20 0x0000000000aa5e77 in main (argc_=65, argv_=0x7fffffffc058) at
/local/mnt/workspace/slarin/tools/llvm-mainline-merged/tools/clang/tools/dri
ver/driver.cpp:353


Thanks.

Sergei