dist/gcc/shrink-wrap.cc

1034    can put parts of it in places where those components are executed less
1036    components that can be put in more than one location, and where those
1037    components can be executed more than once (the epilogue component will
1042    components are simple saves/restores to/from the frame of callee-saved
1043    registers.  This code treats components abstractly (as an sbitmap),
1046    Prologue components are placed in such a way that for every component
1054    get a prologue inserted.  That then is how the components are placed.
1055    We could place the epilogue components a bit smarter (we can save a
1065    where we want to put them), separate shrink-wrapping for the components
1072 dump_components (const char *label, sbitmap components)
1074   if (bitmap_empty_p (components))
1079   for (unsigned int j = 0; j < components->n_bits; j++)
1080     if (bitmap_bit_p (components, j))
1088   /* What components does this BB need?  */
1091   /* What components does this BB have?  This is the main decision this
1095   /* The components for which we placed code at the start of the BB (instead
1099   /* The components for which we placed code at the end of the BB (instead
1123    with components COMPONENTS.  */
1125 init_separate_shrink_wrap (sbitmap components)
1134       /* Mark all basic blocks without successor as needing all components.
1139 	bitmap_copy (SW (bb)->needs_components, components);
1143 	  fprintf (dump_file, "bb %d components:", bb->index);
1148       SW (bb)->has_components = sbitmap_alloc (SBITMAP_SIZE (components));
1149       SW (bb)->head_components = sbitmap_alloc (SBITMAP_SIZE (components));
1150       SW (bb)->tail_components = sbitmap_alloc (SBITMAP_SIZE (components));
1278 spread_components (sbitmap components)
1289   auto_sbitmap old (SBITMAP_SIZE (components));
1291   /* Find for every block the components that are *not* needed on some path
1294      components (plus one), and usually much less often.  */
1303   bitmap_copy (SW (entry_block)->head_components, components);
1331   /* Find for every block the components that are *not* needed on some reverse
1342     bitmap_copy (SW (bb)->tail_components, components);
1364   /* And then, flood fill backwards to find for every block the components
1367   bitmap_copy (SW (exit_block)->tail_components, components);
1408       bitmap_and_compl (SW (bb)->has_components, components,
1419 	  fprintf (dump_file, "bb %d components:", bb->index);
1432 disqualify_problematic_components (sbitmap components)
1434   auto_sbitmap pro (SBITMAP_SIZE (components));
1435   auto_sbitmap epi (SBITMAP_SIZE (components));
1444 	  /* Find which components we want pro/epilogues for here.  */
1452 	    targetm.shrink_wrap.disqualify_components (components, e, epi,
1455 	    targetm.shrink_wrap.disqualify_components (components, e, pro,
1474 	  /* Remove from consideration those components we would need
1476 	  bitmap_and_compl (components, components, epi);
1477 	  bitmap_and_compl (components, components, pro);
1479 	  if (dump_file && !bitmap_subset_p (epi, components))
1489 	  if (dump_file && !bitmap_subset_p (pro, components))
1505 emit_common_heads_for_components (sbitmap components)
1507   auto_sbitmap pro (SBITMAP_SIZE (components));
1508   auto_sbitmap epi (SBITMAP_SIZE (components));
1509   auto_sbitmap tmp (SBITMAP_SIZE (components));
1517       /* Find which prologue resp. epilogue components are needed for all
1520       /* First, select all possible components.  */
1521       bitmap_copy (epi, components);
1522       bitmap_copy (pro, components);
1535 	  /* Deselect those epilogue components that should not be inserted
1590 emit_common_tails_for_components (sbitmap components)
1592   auto_sbitmap pro (SBITMAP_SIZE (components));
1593   auto_sbitmap epi (SBITMAP_SIZE (components));
1594   auto_sbitmap tmp (SBITMAP_SIZE (components));
1602       /* Find which prologue resp. epilogue components are needed for all
1607       /* First, select all possible components.  */
1608       bitmap_copy (epi, components);
1609       bitmap_copy (pro, components);
1622 	  /* Deselect those epilogue components that should not be inserted
1696 insert_prologue_epilogue_for_components (sbitmap components)
1698   auto_sbitmap pro (SBITMAP_SIZE (components));
1699   auto_sbitmap epi (SBITMAP_SIZE (components));
1711 	  /* Find which pro/epilogue components are needed on this edge.  */
1716 	  bitmap_and (epi, epi, components);
1717 	  bitmap_and (pro, pro, components);
1741 	      /* Put the epilogue components in place.  */
1765 	      /* Put the prologue components in place.  */
1800   /* Ask the target what components there are.  If it returns NULL, don't
1802   sbitmap components = targetm.shrink_wrap.get_separate_components ();
1803   if (!components)
1819   init_separate_shrink_wrap (components);
1823   EXECUTE_IF_SET_IN_BITMAP (components, 0, j, sbi)
1829   while (spread_components (components))
1837   disqualify_problematic_components (components);
1841      all components together (say, if it generates store-multiple insns).  */
1842   bitmap_and_compl (components, components, SW (first_bb)->has_components);
1844   if (bitmap_empty_p (components))
1853 	  fprintf (dump_file, "The components we wrap separately are");
1854 	  dump_components ("sep", components);
1860       emit_common_heads_for_components (components);
1865       emit_common_tails_for_components (components);
1870       insert_prologue_epilogue_for_components (components);
1875       targetm.shrink_wrap.set_handled_components (components);
1882   sbitmap_free (components);