[LLVMdev] A question about induction variables
Vladimir Prus
ghost at cs.msu.su
Wed Mar 31 09:17:03 PST 2004
Hello,
I've just downloaded the latest release of LLVM, and playing with the
following simple example:
int main()
{
int r(0);
for (int i = 0; i < 100; ++i)
r += i;
;
return r;
}
I compile it and then run:
analyze -indvars x.bc
which prints:
Printing analysis 'Induction Variable Analysis' for function 'main':
and nothing else. It is a bit strange -- since 'i' is clearly an induction
variable and the resulting loop in assembler should have some induction
variable too. Does this mean that induction variable analysis is not fully
implemented, or there's some error on my part?
If I don't use the 'r' variable, but just loop with empty body, the entire
loop seems to be optimized out, but in this example the loop is still there
in assembler.
Thanks in advance,
Volodya
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