[LLVMdev] Unnatural loops with O0

[Duncan Sands]

Hi Marc,

> Is there a compelling reason why llvm-gcc does not always produce natural
> loops.  Is it a code size issue, or are there performance implications as
> well?  I am seeing a simple 'while' loop compiled to an unnatural loop,
> without any gotos, breaks, or continues.  What is the reason for this?

is it already an unnatural loop when it comes out of the gcc parts of
llvm-gcc (you can check this by compiling with: -O0 -emit-llvm)?  Or
is it llvm itself that creates the unnatural loops?

Ciao,

Duncan.