/* Control flow graph manipulation code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
This file is part of GCC.
#include "toplev.h"
#include "tm_p.h"
#include "obstack.h"
+#include "insn-attr.h"
#include "insn-config.h"
#include "cfglayout.h"
#include "expr.h"
static int can_delete_note_p (const_rtx);
static int can_delete_label_p (const_rtx);
-static void commit_one_edge_insertion (edge);
static basic_block rtl_split_edge (edge);
static bool rtl_move_block_after (basic_block, basic_block);
static int rtl_verify_flow_info (void);
start = next;
}
}
-
-/* Like delete_insn_chain but also purge dead edges from BB. */
-
-void
-delete_insn_chain_and_edges (rtx first, rtx last)
-{
- bool purge = false;
-
- if (INSN_P (last)
- && BLOCK_FOR_INSN (last)
- && BB_END (BLOCK_FOR_INSN (last)) == last)
- purge = true;
- delete_insn_chain (first, last, false);
- if (purge)
- purge_dead_edges (BLOCK_FOR_INSN (last));
-}
\f
/* Create a new basic block consisting of the instructions between HEAD and END
inclusive. This function is designed to allow fast BB construction - reuses
label for an exception handler which can't be reached. We need
to remove the label from the exception_handler_label list. */
insn = BB_HEAD (b);
- if (LABEL_P (insn))
- maybe_remove_eh_handler (insn);
end = get_last_bb_insn (b);
return 0;
}
+static unsigned int
+rest_of_pass_free_cfg (void)
+{
+#ifdef DELAY_SLOTS
+ /* The resource.c machinery uses DF but the CFG isn't guaranteed to be
+ valid at that point so it would be too late to call df_analyze. */
+ if (optimize > 0 && flag_delayed_branch)
+ df_analyze ();
+#endif
+
+ free_bb_for_insn ();
+ return 0;
+}
+
struct rtl_opt_pass pass_free_cfg =
{
{
RTL_PASS,
NULL, /* name */
NULL, /* gate */
- free_bb_for_insn, /* execute */
+ rest_of_pass_free_cfg, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
+ TV_NONE, /* tv_id */
0, /* properties_required */
0, /* properties_provided */
PROP_cfg, /* properties_destroyed */
/* If there was a CODE_LABEL beginning B, delete it. */
if (LABEL_P (b_head))
{
- /* This might have been an EH label that no longer has incoming
- EH edges. Update data structures to match. */
- maybe_remove_eh_handler (b_head);
-
/* Detect basic blocks with nothing but a label. This can happen
in particular at the end of a function. */
if (b_head == b_end)
return e;
}
-/* Redirect edge representing branch of (un)conditional jump or tablejump,
- NULL on failure */
-static edge
-redirect_branch_edge (edge e, basic_block target)
+/* Subroutine of redirect_branch_edge that tries to patch the jump
+ instruction INSN so that it reaches block NEW. Do this
+ only when it originally reached block OLD. Return true if this
+ worked or the original target wasn't OLD, return false if redirection
+ doesn't work. */
+
+static bool
+patch_jump_insn (rtx insn, rtx old_label, basic_block new_bb)
{
rtx tmp;
- rtx old_label = BB_HEAD (e->dest);
- basic_block src = e->src;
- rtx insn = BB_END (src);
-
- /* We can only redirect non-fallthru edges of jump insn. */
- if (e->flags & EDGE_FALLTHRU)
- return NULL;
- else if (!JUMP_P (insn))
- return NULL;
-
/* Recognize a tablejump and adjust all matching cases. */
if (tablejump_p (insn, NULL, &tmp))
{
rtvec vec;
int j;
- rtx new_label = block_label (target);
+ rtx new_label = block_label (new_bb);
- if (target == EXIT_BLOCK_PTR)
- return NULL;
+ if (new_bb == EXIT_BLOCK_PTR)
+ return false;
if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
vec = XVEC (PATTERN (tmp), 0);
else
if (computed_jump_p (insn)
/* A return instruction can't be redirected. */
|| returnjump_p (insn))
- return NULL;
+ return false;
- /* If the insn doesn't go where we think, we're confused. */
- gcc_assert (JUMP_LABEL (insn) == old_label);
-
- /* If the substitution doesn't succeed, die. This can happen
- if the back end emitted unrecognizable instructions or if
- target is exit block on some arches. */
- if (!redirect_jump (insn, block_label (target), 0))
+ if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label)
{
- gcc_assert (target == EXIT_BLOCK_PTR);
- return NULL;
+ /* If the insn doesn't go where we think, we're confused. */
+ gcc_assert (JUMP_LABEL (insn) == old_label);
+
+ /* If the substitution doesn't succeed, die. This can happen
+ if the back end emitted unrecognizable instructions or if
+ target is exit block on some arches. */
+ if (!redirect_jump (insn, block_label (new_bb), 0))
+ {
+ gcc_assert (new_bb == EXIT_BLOCK_PTR);
+ return false;
+ }
}
}
+ return true;
+}
+
+
+/* Redirect edge representing branch of (un)conditional jump or tablejump,
+ NULL on failure */
+static edge
+redirect_branch_edge (edge e, basic_block target)
+{
+ rtx old_label = BB_HEAD (e->dest);
+ basic_block src = e->src;
+ rtx insn = BB_END (src);
+
+ /* We can only redirect non-fallthru edges of jump insn. */
+ if (e->flags & EDGE_FALLTHRU)
+ return NULL;
+ else if (!JUMP_P (insn) && !currently_expanding_to_rtl)
+ return NULL;
+
+ if (!currently_expanding_to_rtl)
+ {
+ if (!patch_jump_insn (insn, old_label, target))
+ return NULL;
+ }
+ else
+ /* When expanding this BB might actually contain multiple
+ jumps (i.e. not yet split by find_many_sub_basic_blocks).
+ Redirect all of those that match our label. */
+ for (insn = BB_HEAD (src); insn != NEXT_INSN (BB_END (src));
+ insn = NEXT_INSN (insn))
+ if (JUMP_P (insn) && !patch_jump_insn (insn, old_label, target))
+ return NULL;
if (dump_file)
fprintf (dump_file, "Edge %i->%i redirected to %i\n",
/* Update the CFG for the instructions queued on edge E. */
-static void
+void
commit_one_edge_insertion (edge e)
{
rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
}
FOR_BB_INSNS (bb, insn)
- if (!BARRIER_P (insn)
- && BLOCK_FOR_INSN (insn) != bb)
+ if (BLOCK_FOR_INSN (insn) != bb)
{
error ("insn %d basic block pointer is %d, should be %d",
INSN_UID (insn),
/* If there was a CODE_LABEL beginning B, delete it. */
if (LABEL_P (BB_HEAD (b)))
{
- /* This might have been an EH label that no longer has incoming
- EH edges. Update data structures to match. */
- maybe_remove_eh_handler (BB_HEAD (b));
-
delete_insn (BB_HEAD (b));
}
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