------- Comment #1 from steven at gcc dot gnu dot org 2010-02-13 23:18 ------- Breakpoint 7, rest_of_handle_sched2 () at ../../trunk/gcc/sched-rgn.c:3534 3534 && ! maybe_skip_selective_scheduling ()) (gdb) p brief_dump_cfg(stderr) Basic block 2 (reachable, rtl) Predecessors: ENTRY [100.0%] (fallthru) Successors: EXIT [100.0%]
The .split4 dump (just before .sched2): ;; Function foo (foo) 1 NOTE_INSN_DELETED 3 NOTE_INSN_BASIC_BLOCK 9 NOTE_INSN_PROLOGUE_END 2 NOTE_INSN_FUNCTION_BEG 5 prefetch(`x',0x0,0x3) 10 NOTE_INSN_EPILOGUE_BEG 11 return i 12: barrier 8 NOTE_INSN_DELETED And the .sched2 dump: changing bb of uid 13 unscanned insn changing bb of uid 5 from 2 to 3 deleting block 3 1 NOTE_INSN_DELETED 3 NOTE_INSN_BASIC_BLOCK 9 NOTE_INSN_PROLOGUE_END 2 NOTE_INSN_FUNCTION_BEG 14 NOTE_INSN_EPILOGUE_BEG 11 return 8 NOTE_INSN_DELETED What insn 13? What basic block 3? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43056