Method find_loop_headers

cranelift/codegen/src/loop_analysis.rs:203–212

Traverses the CFG in reverse postorder and create a loop object for every block having a back edge.

(&mut self, cfg: &ControlFlowGraph, domtree: &DominatorTree)

    // Traverses the CFG in reverse postorder and create a loop object for every block having a
    // back edge.
    fn find_loop_headers(&mut self, cfg: &ControlFlowGraph, domtree: &DominatorTree) {
        for &block in domtree
            .cfg_rpo()
            .filter(|&&block| Self::is_block_loop_header(block, cfg, domtree))
        {
            // This block is a loop header, so we create its associated loop
            let lp = self.loops.push(LoopData::new(block, None));
            self.block_loop_map[block] = lp.into();
        }
    }

    // Intended to be called after `find_loop_headers`. For each detected loop header,
    // discovers all the block belonging to the loop and its inner loops. After a call to this