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cfgexpand.c (expand_gimple_tailcall): Fix case where we need to create a new basic block.

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* cfgexpand.c (expand_gimple_tailcall): Fix case where we need
        to create a new basic block.

From-SVN: r85029
This commit is contained in:
Richard Henderson 2004-07-21 17:45:54 -07:00 committed by Richard Henderson
parent 7761cda3b4
commit 224e770bb8
2 changed files with 83 additions and 60 deletions

5
gcc/ChangeLog

@ -1,3 +1,8 @@
2004-07-21 Richard Henderson <rth@redhat.com>
* cfgexpand.c (expand_gimple_tailcall): Fix case where we need
to create a new basic block.
2004-07-22 Joseph S. Myers <jsm@polyomino.org.uk>
PR c/15052

138
gcc/cfgexpand.c

@ -111,77 +111,95 @@ expand_gimple_cond_expr (basic_block bb, tree stmt)
}
/* A subroutine of expand_gimple_basic_block. Expand one CALL_EXPR
that has CALL_EXPR_TAILCALL set. Returns a new basic block if we've
terminated the current basic block and created a new one. */
that has CALL_EXPR_TAILCALL set. Returns non-null if we actually
generated a tail call (something that might be denied by the ABI
rules governing the call; see calls.c). */
static basic_block
expand_gimple_tailcall (basic_block bb, tree stmt)
{
rtx last = get_last_insn ();
edge e;
int probability;
gcov_type count;
expand_expr_stmt (stmt);
for (last = NEXT_INSN (last); last; last = NEXT_INSN (last))
{
if (CALL_P (last) && SIBLING_CALL_P (last))
{
edge e;
int probability = 0;
gcov_type count = 0;
do_pending_stack_adjust ();
e = bb->succ;
while (e)
{
edge next = e->succ_next;
if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
{
if (e->dest != EXIT_BLOCK_PTR)
{
e->dest->count -= e->count;
e->dest->frequency -= EDGE_FREQUENCY (e);
if (e->dest->count < 0)
e->dest->count = 0;
if (e->dest->frequency < 0)
e->dest->frequency = 0;
}
count += e->count;
probability += e->probability;
remove_edge (e);
}
e = next;
}
/* This is somewhat ugly: the call_expr expander often emits
instructions after the sibcall (to perform the function
return). These confuse the find_sub_basic_blocks code,
so we need to get rid of these. */
last = NEXT_INSN (last);
if (!BARRIER_P (last))
abort ();
while (NEXT_INSN (last))
{
/* For instance an sqrt builtin expander expands if with
sibcall in the then and label for `else`. */
if (LABEL_P (NEXT_INSN (last)))
break;
delete_insn (NEXT_INSN (last));
}
e = make_edge (bb, EXIT_BLOCK_PTR, EDGE_ABNORMAL | EDGE_SIBCALL);
e->probability += probability;
e->count += count;
BB_END (bb) = last;
update_bb_for_insn (bb);
if (NEXT_INSN (last))
bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);
else
return bb;
}
}
if (CALL_P (last) && SIBLING_CALL_P (last))
goto found;
return NULL;
found:
/* ??? Wouldn't it be better to just reset any pending stack adjust?
Any instructions emitted here are about to be deleted. */
do_pending_stack_adjust ();
/* Remove any non-eh, non-abnormal edges that don't go to exit. */
/* ??? I.e. the fallthrough edge. HOWEVER! If there were to be
EH or abnormal edges, we shouldn't have created a tail call in
the first place. So it seems to me we should just be removing
all edges here, or redirecting the existing fallthru edge to
the exit block. */
e = bb->succ;
probability = 0;
count = 0;
while (e)
{
edge next = e->succ_next;
if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
{
if (e->dest != EXIT_BLOCK_PTR)
{
e->dest->count -= e->count;
e->dest->frequency -= EDGE_FREQUENCY (e);
if (e->dest->count < 0)
e->dest->count = 0;
if (e->dest->frequency < 0)
e->dest->frequency = 0;
}
count += e->count;
probability += e->probability;
remove_edge (e);
}
e = next;
}
/* This is somewhat ugly: the call_expr expander often emits instructions
after the sibcall (to perform the function return). These confuse the
find_sub_basic_blocks code, so we need to get rid of these. */
last = NEXT_INSN (last);
if (!BARRIER_P (last))
abort ();
while (NEXT_INSN (last))
{
/* For instance an sqrt builtin expander expands if with
sibcall in the then and label for `else`. */
if (LABEL_P (NEXT_INSN (last)))
break;
delete_insn (NEXT_INSN (last));
}
e = make_edge (bb, EXIT_BLOCK_PTR, EDGE_ABNORMAL | EDGE_SIBCALL);
e->probability += probability;
e->count += count;
BB_END (bb) = last;
update_bb_for_insn (bb);
if (NEXT_INSN (last))
{
bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);
last = BB_END (bb);
if (BARRIER_P (last))
BB_END (bb) = PREV_INSN (last);
}
return bb;
}
/* Expand basic block BB from GIMPLE trees to RTL. */