#error "Both MODE_ENTRY and MODE_EXIT must be defined"
#endif
+#if defined (MODE_ENTRY) && defined (MODE_EXIT)
+/* Split the fallthrough edge to the exit block, so that we can note
+ that there NORMAL_MODE is required. Return the new block if it's
+ inserted before the exit block. Otherwise return null. */
+
+static basic_block
+create_pre_exit (int n_entities, int *entity_map, const int *num_modes)
+{
+ edge eg;
+ edge_iterator ei;
+ basic_block pre_exit;
+
+ /* The only non-call predecessor at this stage is a block with a
+ fallthrough edge; there can be at most one, but there could be
+ none at all, e.g. when exit is called. */
+ pre_exit = 0;
+ FOR_EACH_EDGE (eg, ei, EXIT_BLOCK_PTR->preds)
+ if (eg->flags & EDGE_FALLTHRU)
+ {
+ basic_block src_bb = eg->src;
+ regset live_at_end = src_bb->global_live_at_end;
+ rtx last_insn, ret_reg;
+
+ gcc_assert (!pre_exit);
+ /* If this function returns a value at the end, we have to
+ insert the final mode switch before the return value copy
+ to its hard register. */
+ if (EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 1
+ && GET_CODE ((last_insn = BB_END (src_bb))) == INSN
+ && GET_CODE (PATTERN (last_insn)) == USE
+ && GET_CODE ((ret_reg = XEXP (PATTERN (last_insn), 0))) == REG)
+ {
+ int ret_start = REGNO (ret_reg);
+ int nregs = hard_regno_nregs[ret_start][GET_MODE (ret_reg)];
+ int ret_end = ret_start + nregs;
+ int short_block = 0;
+ int maybe_builtin_apply = 0;
+ int forced_late_switch = 0;
+ rtx before_return_copy;
+
+ do
+ {
+ rtx return_copy = PREV_INSN (last_insn);
+ rtx return_copy_pat, copy_reg;
+ int copy_start, copy_num;
+ int j;
+
+ if (INSN_P (return_copy))
+ {
+ if (GET_CODE (PATTERN (return_copy)) == USE
+ && GET_CODE (XEXP (PATTERN (return_copy), 0)) == REG
+ && (FUNCTION_VALUE_REGNO_P
+ (REGNO (XEXP (PATTERN (return_copy), 0)))))
+ {
+ maybe_builtin_apply = 1;
+ last_insn = return_copy;
+ continue;
+ }
+ /* If the return register is not (in its entirety)
+ likely spilled, the return copy might be
+ partially or completely optimized away. */
+ return_copy_pat = single_set (return_copy);
+ if (!return_copy_pat)
+ {
+ return_copy_pat = PATTERN (return_copy);
+ if (GET_CODE (return_copy_pat) != CLOBBER)
+ break;
+ }
+ copy_reg = SET_DEST (return_copy_pat);
+ if (GET_CODE (copy_reg) == REG)
+ copy_start = REGNO (copy_reg);
+ else if (GET_CODE (copy_reg) == SUBREG
+ && GET_CODE (SUBREG_REG (copy_reg)) == REG)
+ copy_start = REGNO (SUBREG_REG (copy_reg));
+ else
+ break;
+ if (copy_start >= FIRST_PSEUDO_REGISTER)
+ break;
+ copy_num
+ = hard_regno_nregs[copy_start][GET_MODE (copy_reg)];
+
+ /* If the return register is not likely spilled, - as is
+ the case for floating point on SH4 - then it might
+ be set by an arithmetic operation that needs a
+ different mode than the exit block. */
+ for (j = n_entities - 1; j >= 0; j--)
+ {
+ int e = entity_map[j];
+ int mode = MODE_NEEDED (e, return_copy);
+
+ if (mode != num_modes[e] && mode != MODE_EXIT (e))
+ break;
+ }
+ if (j >= 0)
+ {
+ /* For the SH4, floating point loads depend on fpscr,
+ thus we might need to put the final mode switch
+ after the return value copy. That is still OK,
+ because a floating point return value does not
+ conflict with address reloads. */
+ if (copy_start >= ret_start
+ && copy_start + copy_num <= ret_end
+ && OBJECT_P (SET_SRC (return_copy_pat)))
+ forced_late_switch = 1;
+ break;
+ }
+
+ if (copy_start >= ret_start
+ && copy_start + copy_num <= ret_end)
+ nregs -= copy_num;
+ else if (!maybe_builtin_apply
+ || !FUNCTION_VALUE_REGNO_P (copy_start))
+ break;
+ last_insn = return_copy;
+ }
+ /* ??? Exception handling can lead to the return value
+ copy being already separated from the return value use,
+ as in unwind-dw2.c .
+ Similarly, conditionally returning without a value,
+ and conditionally using builtin_return can lead to an
+ isolated use. */
+ if (return_copy == BB_HEAD (src_bb))
+ {
+ short_block = 1;
+ break;
+ }
+ last_insn = return_copy;
+ }
+ while (nregs);
+ /* If we didn't see a full return value copy, verify that there
+ is a plausible reason for this. If some, but not all of the
+ return register is likely spilled, we can expect that there
+ is a copy for the likely spilled part. */
+ if (nregs
+ && ! forced_late_switch
+ && ! short_block
+ && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (ret_start))
+ && nregs == hard_regno_nregs[ret_start][GET_MODE (ret_reg)]
+ /* For multi-hard-register floating point values,
+ sometimes the likely-spilled part is ordinarily copied
+ first, then the other part is set with an arithmetic
+ operation. This doesn't actually cause reload failures,
+ so let it pass. */
+ && (GET_MODE_CLASS (GET_MODE (ret_reg)) == MODE_INT
+ || nregs == 1))
+ abort ();
+ if (INSN_P (last_insn))
+ {
+ before_return_copy
+ = emit_note_before (NOTE_INSN_DELETED, last_insn);
+ /* Instructions preceding LAST_INSN in the same block might
+ require a different mode than MODE_EXIT, so if we might
+ have such instructions, keep them in a separate block
+ from pre_exit. */
+ if (last_insn != BB_HEAD (src_bb))
+ src_bb = split_block (src_bb,
+ PREV_INSN (before_return_copy))->dest;
+ }
+ else
+ before_return_copy = last_insn;
+ pre_exit = split_block (src_bb, before_return_copy)->src;
+ }
+ else
+ {
+ pre_exit = split_edge (eg);
+ COPY_REG_SET (pre_exit->global_live_at_start, live_at_end);
+ COPY_REG_SET (pre_exit->global_live_at_end, live_at_end);
+ }
+ }
+
+ return pre_exit;
+}
+#endif
+
/* Find all insns that need a particular mode setting, and insert the
necessary mode switches. Return true if we did work. */
If NORMAL_MODE is defined, allow for two extra
blocks split from the entry and exit block. */
#if defined (MODE_ENTRY) && defined (MODE_EXIT)
- entry_exit_extra = 2;
+ entry_exit_extra = 3;
#endif
bb_info[n_entities]
= xcalloc (last_basic_block + entry_exit_extra, sizeof **bb_info);
return 0;
#if defined (MODE_ENTRY) && defined (MODE_EXIT)
- {
- /* Split the edge from the entry block and the fallthrough edge to the
- exit block, so that we can note that there NORMAL_MODE is supplied /
- required. */
- edge eg;
- edge_iterator ei;
- post_entry = split_edge (EDGE_SUCC (ENTRY_BLOCK_PTR, 0));
- /* The only non-call predecessor at this stage is a block with a
- fallthrough edge; there can be at most one, but there could be
- none at all, e.g. when exit is called. */
- pre_exit = 0;
- FOR_EACH_EDGE (eg, ei, EXIT_BLOCK_PTR->preds)
- if (eg->flags & EDGE_FALLTHRU)
- {
- regset live_at_end = eg->src->global_live_at_end;
-
- gcc_assert (!pre_exit);
- pre_exit = split_edge (eg);
- COPY_REG_SET (pre_exit->global_live_at_start, live_at_end);
- COPY_REG_SET (pre_exit->global_live_at_end, live_at_end);
- }
- }
+ /* Split the edge from the entry block, so that we can note that
+ there NORMAL_MODE is supplied. */
+ post_entry = split_edge (EDGE_SUCC (ENTRY_BLOCK_PTR, 0));
+ pre_exit = create_pre_exit (n_entities, entity_map, num_modes);
#endif
/* Create the bitmap vectors. */
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