[LLVMdev] Which is the better optimization?
Seung Jae Lee
lee225 at uiuc.edu
Tue Mar 11 17:36:14 PDT 2008
While making some bitcodes from HL source codes including loops, I came to wonder which was the better one for the optimization between:
llvm-gcc -O4 .... (using llvm-gcc optimization)
llvm-gcc -O0 .... (nonoptimization of llvm-gcc)
opt -mem2reg -instcombine -indvars .... (w/ optimization pass)
After some trials, 'llvm-gcc -O4' seemed better for optimization but not sure.
Bitcodes from 'llvm-gcc -O0' w/ 'opt' were quite neat so easy to read and sometimes used less basic blocks than that from 'llvm-gcc -O4' trial.
I am not sure about this, is there any body familiar with this? :^)
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