Displaying 2 results from an estimated 2 matches for "r153260".
2020 Mar 26
5
canonical form loops
Hello,
Quick question to see if I haven't missed anything: I would like convert counting down loops, i.e. loops with a constant -1 step value, to counting up loops, because the vectoriser is able to better deal with these loops (see e.g. D76838 that I was discussing today with Ayal). It looks like LoopSimplifyCFG and IndVarSimplify don't do this. So was just curious if I haven't
2020 Apr 01
2
canonical form loops
...33502 introduced -disable-iv-rewrite to rely more on ScalarEvolution
> instead of "opcode/pattern matching" (cite from the commit message). -
> enable-iv-rewrite=false was made the default in r139579 after finding that it
> slows down many benchmarks. It was completely removed in r153260.
>
> The general approach in LLVM is to rely on SCEV for analyzing loops instead
> of custom handling. As a consequence, any loop structure that is recognized
> by SCEV will (/should) not profit from rewriting.
>
> Michael
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> Am Do., 26. März 2020 um 15...