On Wed, Sep 24, 2014 at 2:30 PM, Ilya Enkovich wrote: > I didn't generate references separately from label. Now I found an > old patch and a test where this problem appeared. In this patch I > moved set_rip generation currently performed in ix86_expand_prologue > into expand pass. And I got following code in expand dump for > testsuite/gcc.target/i386/pr55154.c test: > > (note 7 1 2 2 [bb 2] NOTE_INSN_BASIC_BLOCK) > (note/s 2 7 3 2 "" NOTE_INSN_DELETED_LABEL 2) > (insn 3 2 4 2 (set (reg:DI 85) > (unspec:DI [ > (label_ref [2 deleted]) > ] UNSPEC_SET_RIP)) > /export/users/ienkovic/issues/4161/gcc/gcc/testsuite/gcc.target/i386/pr55154.c:9 > -1 > (insn_list:REG_LABEL_OPERAND 2 (nil))) > > There is a REG_LABEL_OPERAND generated but label is still removed.
Because it should be a REG_LABEL_TARGET? AFAUI this is a contol flow insn so I'd expect it to be a jump_insn (and the note will be a TARGET note). But it's not a PC-set insn and a jump target the compiler will interpret as an infinite loop (if the insns are really in the order as above) which is clearly not what you want. So if you emit it as a jump_insn I'm not sure what will happen... Is it necessary to emit the label into a basic block? Ciao! Steven
