[fernando@samoa base1Sum]$ llc -f -regalloc=linearscan exec.bc -o exec.s -enable-correct-eh-support --debug-pass=Structure
Pass Arguments:  -preverify -domtree -verify -loops -loopsimplify -scalar-evolution -loop-reduce -lowerinvoke -unreachableblockelim -codegenprepare -livevars -phi-node-elimination -twoaddressinstruction -liveintervals -machinedomtree -machine-loops -simple-register-coalescing
Target Data Layout
Create Garbage Collector Module Metadata
Basic Alias Analysis (default AA impl)
Module Information
  FunctionPass Manager
    Preliminary module verification
    Dominator Tree Construction
    Module Verifier
--    Module Verifier
--    Preliminary module verification
    Natural Loop Construction
    Canonicalize natural loops
    Scalar Evolution Analysis
    Loop Pass Manager
      Loop Strength Reduction
--      Loop Strength Reduction
--    Target Data Layout
--    Scalar Evolution Analysis
--    Dominator Tree Construction
--    Canonicalize natural loops
--    Natural Loop Construction
    Lower Garbage Collection Instructions
--    Lower Garbage Collection Instructions
    Lower invoke and unwind, for unwindless code generators
--    Lower invoke and unwind, for unwindless code generators
    Remove unreachable blocks from the CFG
--    Remove unreachable blocks from the CFG
    Optimize for code generation
--    Optimize for code generation
    X86 DAG->DAG Instruction Selection
--    X86 DAG->DAG Instruction Selection
    Live Variable Analysis
    Eliminate PHI nodes for register allocation
    Two-Address instruction pass
    Live Interval Analysis
    MachineDominator Tree Construction
    Machine Natural Loop Construction
    Simple Register Coalescing
    Linear Scan Register Allocator
--    Linear Scan Register Allocator
--    Live Interval Analysis
--    Machine Natural Loop Construction
--    Live Variable Analysis
--    Eliminate PHI nodes for register allocation
--    Two-Address instruction pass
--    Simple Register Coalescing
--    MachineDominator Tree Construction
    Subregister lowering instruction pass
--    Subregister lowering instruction pass
    X86 FP Stackifier
--    X86 FP Stackifier
    Prolog/Epilog Insertion & Frame Finalization
--    Prolog/Epilog Insertion & Frame Finalization
    Control Flow Optimizer
--    Control Flow Optimizer
    Analyze Machine Code For Garbage Collection
--    Analyze Machine Code For Garbage Collection
    Label Folder
--    Label Folder
    X86 AT&T-Style Assembly Printer
--    X86 AT&T-Style Assembly Printer
    Delete Garbage Collector Information
--    Delete Garbage Collector Information
    Machine Code Deleter
--    Machine Code Deleter