[tree-ssa] goto <bb x>

[Andrew MacLeod <amacleod at redhat dot com>]

Although I like showing the implicit goto's in this form
   GOTO <bb 3>

its unfortunately not very useful if we aren't showing the basic block
info.

Ie, I look at a listing out of .dom1 for instance with
-fdump-tree-all-details-vops, and I see:

<L2>:;
  #   VUSE <MT.5_8>;
  iftmp.4_13 = t_7->decl.rtl;
  goto <bb 5>;

<L3>:;
  #   MT.5_14 = VDEF <MT.5_8>;
  make_decl_rtl (t_7, 0);
  #   VUSE <MT.5_14>;
  iftmp.4_15 = t_7->decl.rtl;

  # iftmp.4_4 = PHI <iftmp.4_13(3), iftmp.4_15(4)>;
  # MT.5_2 = PHI <MT.5_8(3), MT.5_14(4)>;
<L4>:;
  #   VUSE <MT.5_2>;
  iftmp.2_16 = iftmp.4_4->fld[1].rtmem;
  goto <bb 7>;

<L5>:;
  iftmp.2_17 = 0B;

  # iftmp.2_6 = PHI <iftmp.2_16(5), iftmp.2_17(6)>;
  # iftmp.4_5 = PHI <iftmp.4_4(5), iftmp.4_18(6)>;
  # MT.5_3 = PHI <MT.5_2(5), MT.5_8(6)>;
  # T.1_1 = PHI <T.1_12(5), T.1_10(6)>;
<L6>:;
  return iftmp.2_6;


I can't tell be looking where the goto <bb5> or goto <bb 7> actually go.
bb_5 is in fact <L4> and bb 7 is <L6>, but its hard to figure that out,
especially in a larger program.

Would it be possible to check the first stmt of a target block and use
that label in the goto if we aren't dumping the bb info?  (If there is a
label there.). Im finding it difficult to work with in this case.

Andrew