/* Standard problems for dataflow support routines.
Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
- 2008 Free Software Foundation, Inc.
+ 2008, 2009 Free Software Foundation, Inc.
Originally contributed by Michael P. Hayes
(m.hayes@elec.canterbury.ac.nz, mhayes@redhat.com)
Major rewrite contributed by Danny Berlin (dberlin@dberlin.org)
}
/* Set up the knockout bit vectors to be applied across EH_EDGES. */
- EXECUTE_IF_SET_IN_BITMAP (df_invalidated_by_call, 0, regno, bi)
+ EXECUTE_IF_SET_IN_BITMAP (regs_invalidated_by_call_regset, 0, regno, bi)
{
if (DF_DEFS_COUNT (regno) > DF_SPARSE_THRESHOLD)
bitmap_set_bit (sparse_invalidated, regno);
/* ??? Abnormal call edges ignored for the moment, as this gets
confused by sibling call edges, which crashes reg-stack. */
if (e->flags & EDGE_EH)
- bitmap_ior_and_compl_into (op1, op2, df_invalidated_by_call);
+ bitmap_ior_and_compl_into (op1, op2, regs_invalidated_by_call_regset);
else
bitmap_ior_into (op1, op2);
/* Run the fast dce as a side effect of building LR. */
static void
-df_lr_finalize (bitmap all_blocks ATTRIBUTE_UNUSED)
+df_lr_finalize (bitmap all_blocks)
{
+ df_lr->solutions_dirty = false;
if (df->changeable_flags & DF_LR_RUN_DCE)
{
run_fast_df_dce ();
- if (df_lr->problem_data && df_lr->solutions_dirty)
+
+ /* If dce deletes some instructions, we need to recompute the lr
+ solution before proceeding further. The problem is that fast
+ dce is a pessimestic dataflow algorithm. In the case where
+ it deletes a statement S inside of a loop, the uses inside of
+ S may not be deleted from the dataflow solution because they
+ were carried around the loop. While it is conservatively
+ correct to leave these extra bits, the standards of df
+ require that we maintain the best possible (least fixed
+ point) solution. The only way to do that is to redo the
+ iteration from the beginning. See PR35805 for an
+ example. */
+ if (df_lr->solutions_dirty)
{
- /* If we are here, then it is because we are both verifying
- the solution and the dce changed the function. In that case
- the verification info built will be wrong. So we leave the
- dirty flag true so that the verifier will skip the checking
- part and just clean up.*/
- df_lr->solutions_dirty = true;
+ df_clear_flags (DF_LR_RUN_DCE);
+ df_lr_alloc (all_blocks);
+ df_lr_local_compute (all_blocks);
+ df_worklist_dataflow (df_lr, all_blocks, df->postorder, df->n_blocks);
+ df_lr_finalize (all_blocks);
+ df_set_flags (DF_LR_RUN_DCE);
}
- else
- df_lr->solutions_dirty = false;
}
- else
- df_lr->solutions_dirty = false;
}
df_byte_lr_expand_bitmap (problem_data->hardware_regs_used,
df->hardware_regs_used);
df_byte_lr_expand_bitmap (problem_data->invalidated_by_call,
- df_invalidated_by_call);
+ regs_invalidated_by_call_regset);
EXECUTE_IF_SET_IN_BITMAP (df_byte_lr->out_of_date_transfer_functions, 0, bb_index, bi)
{
The following three functions are used only for BACKWARDS scanning:
i.e. they process the defs before the uses.
- df_simulate_artificial_refs_at_end should be called first with a
+ df_simulate_initialize_backwards should be called first with a
bitvector copyied from the DF_LIVE_OUT or DF_LR_OUT. Then
- df_simulate_one_insn should be called for each insn in the block,
- starting with the last on. Finally,
- df_simulate_artificial_refs_at_top can be called to get a new value
+ df_simulate_one_insn_backwards should be called for each insn in
+ the block, starting with the last on. Finally,
+ df_simulate_finalize_backwards can be called to get a new value
of the sets at the top of the block (this is rarely used).
-
- It would be not be difficult to define a similar set of functions
- that work in the forwards direction. In that case the functions
- would ignore the use sets and look for the REG_DEAD and REG_UNUSED
- notes.
-----------------------------------------------------------------------------*/
+ ----------------------------------------------------------------------------*/
/* Apply the artificial uses and defs at the end of BB in a backwards
direction. */
void
-df_simulate_artificial_refs_at_end (basic_block bb, bitmap live)
+df_simulate_initialize_backwards (basic_block bb, bitmap live)
{
df_ref *def_rec;
df_ref *use_rec;
/* Simulate the backwards effects of INSN on the bitmap LIVE. */
void
-df_simulate_one_insn (basic_block bb, rtx insn, bitmap live)
+df_simulate_one_insn_backwards (basic_block bb, rtx insn, bitmap live)
{
if (! INSN_P (insn))
return;
direction. */
void
-df_simulate_artificial_refs_at_top (basic_block bb, bitmap live)
+df_simulate_finalize_backwards (basic_block bb, bitmap live)
{
df_ref *def_rec;
#ifdef EH_USES
}
#endif
}
+/*----------------------------------------------------------------------------
+ The following three functions are used only for FORWARDS scanning:
+ i.e. they process the defs and the REG_DEAD and REG_UNUSED notes.
+ Thus it is important to add the DF_NOTES problem to the stack of
+ problems computed before using these functions.
+
+ df_simulate_initialize_forwards should be called first with a
+ bitvector copyied from the DF_LIVE_IN or DF_LR_IN. Then
+ df_simulate_one_insn_forwards should be called for each insn in
+ the block, starting with the last on. Finally,
+ df_simulate_finalize_forwards can be called to get a new value
+ of the sets at the bottom of the block (this is rarely used).
+ ----------------------------------------------------------------------------*/
+
+/* Apply the artificial uses and defs at the top of BB in a backwards
+ direction. */
+
+void
+df_simulate_initialize_forwards (basic_block bb, bitmap live)
+{
+ df_ref *def_rec;
+ int bb_index = bb->index;
+
+ for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
+ bitmap_clear_bit (live, DF_REF_REGNO (def));
+ }
+}
+
+/* Simulate the backwards effects of INSN on the bitmap LIVE. */
+
+void
+df_simulate_one_insn_forwards (basic_block bb, rtx insn, bitmap live)
+{
+ rtx link;
+ if (! INSN_P (insn))
+ return;
+
+ /* Make sure that the DF_NOTES really is an active df problem. */
+ gcc_assert (df_note);
+
+ df_simulate_defs (insn, live);
+
+ /* Clear all of the registers that go dead. */
+ for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+ {
+ switch (REG_NOTE_KIND (link))
+ case REG_DEAD:
+ case REG_UNUSED:
+ {
+ rtx reg = XEXP (link, 0);
+ int regno = REGNO (reg);
+ if (regno < FIRST_PSEUDO_REGISTER)
+ {
+ int n = hard_regno_nregs[regno][GET_MODE (reg)];
+ while (--n >= 0)
+ bitmap_clear_bit (live, regno + n);
+ }
+ else
+ bitmap_clear_bit (live, regno);
+ break;
+ default:
+ break;
+ }
+ }
+ df_simulate_fixup_sets (bb, live);
+}
+
+
+/* Apply the artificial uses and defs at the end of BB in a backwards
+ direction. */
+
+void
+df_simulate_finalize_forwards (basic_block bb, bitmap live)
+{
+ df_ref *def_rec;
+ int bb_index = bb->index;
+
+ for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
+ bitmap_clear_bit (live, DF_REF_REGNO (def));
+ }
+}
+
+
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