llvm analysis notes

refs:
http://163.25.101.87/~yen3/wiki/doku.php?id=llvm:llvm_notes

• llvm commands

• Convert C/C++ code to llvm IR

  llvm-g++ -emit-llvm -S test.cpp -o test.ll

• Convert llvm IR to llvm bitcode

  llvm-as test.ll -o test.bc

• Print Control Flow Graph

  opt -dot-cfg test.bc

• Print Dominator Tree Graph

  opt -dot-dom test.bc

• Conver C++ code to C code

  llvm-g++ -emit-llvm test.cpp -o program.bc -c
  llc -march=c program.bc -o program.c

• analysis(ADT analysis, rule check, redundant check, frame remap)
• Alias analysis
• alias memory/register (immutable/mutable) label 
• check different two frames when the input arg is depended from another? 
• CFG analysis
• domain tree, basic block(entry, exist, loop, if/else), operator, reg/mem location
• loop (vector)
• for(i=0;i<10 a1="" a2="" b1="" b2="" c1="" c2="" i="" li="" nbsp="">
• vector(c1,c2) <= {a1,b1} {a2,b2}
• register analysis
• virtual register to physical register(arm r0~r10) , rega, regb, regc
• memory analysis
• load/store analysis(store is depended on load?)
• parallel load/store with different address block in the same BB 
• dependent analysis
• (depend memory? load/store check)
• a[0] = 1; # load from constant input
• b = a[0]; # b is depend from previous assignment, store to output
• split iterator
• for(i=0; i<10 ...="" a="" i="" li="" nbsp="" org="">
• fcheck each unit memory block dependence
•