gcc/testsuite/selftests/cfg-test.rtl

/* Example of a loading a CFG like this:
       0  (entry)
       |
       2
      / \
     3   4
      \ /
       5
       |
       1  (exit).  */

(function "cfg_test"
  (insn-chain
     (block 2
       (edge-from entry (flags "FALLTHRU"))
       (cnote 1 [bb 2] NOTE_INSN_BASIC_BLOCK)
       (edge-to 3 (flags "TRUE_VALUE"))
       (edge-to 4 (flags "FALSE_VALUE"))
     ) ;; block 2
     (block 3
       (edge-from 2 (flags "TRUE_VALUE"))
       (cnote 2 [bb 3] NOTE_INSN_BASIC_BLOCK)
       (edge-to 5 (flags "FALLTHRU"))
     ) ;; block 3
     (block 4
       (edge-from 2 (flags "FALSE_VALUE"))
       (cnote 3 [bb 4] NOTE_INSN_BASIC_BLOCK)
       (edge-to 5 (flags "FALLTHRU"))
     ) ;; block 4
     (block 5
       (edge-from 3 (flags "FALLTHRU"))
       (edge-from 4 (flags "FALLTHRU"))
       (cnote 4 [bb 5] NOTE_INSN_BASIC_BLOCK)
       (edge-to exit (flags "FALLTHRU"))
     ) ;; block 5
  ) ;; insn-chain
) ;; function