/* Control flow graph building code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GCC.
#include "output.h"
#include "function.h"
#include "except.h"
-#include "toplev.h"
+#include "expr.h"
+#include "diagnostic-core.h"
#include "timevar.h"
+#include "sbitmap.h"
static void make_edges (basic_block, basic_block, int);
static void make_label_edge (sbitmap, basic_block, rtx, int);
case CALL_INSN:
case INSN:
+ case DEBUG_INSN:
return true;
case BARRIER:
bool
control_flow_insn_p (const_rtx insn)
{
- rtx note;
-
switch (GET_CODE (insn))
{
case NOTE:
case CODE_LABEL:
+ case DEBUG_INSN:
return false;
case JUMP_INSN:
|| find_reg_note (insn, REG_NORETURN, 0))
&& GET_CODE (PATTERN (insn)) != COND_EXEC)
return true;
+
/* Call insn may return to the nonlocal goto handler. */
- return ((nonlocal_goto_handler_labels
- && (0 == (note = find_reg_note (insn, REG_EH_REGION,
- NULL_RTX))
- || INTVAL (XEXP (note, 0)) >= 0))
- /* Or may trap. */
- || can_throw_internal (insn));
+ if (can_nonlocal_goto (insn))
+ return true;
+ break;
case INSN:
/* Treat trap instructions like noreturn calls (same provision). */
if (GET_CODE (PATTERN (insn)) == TRAP_IF
&& XEXP (PATTERN (insn), 0) == const1_rtx)
return true;
-
- return (flag_non_call_exceptions && can_throw_internal (insn));
+ if (!cfun->can_throw_non_call_exceptions)
+ return false;
+ break;
case BARRIER:
/* It is nonsense to reach barrier when looking for the
default:
gcc_unreachable ();
}
+
+ return can_throw_internal (insn);
}
\f
void
rtl_make_eh_edge (sbitmap edge_cache, basic_block src, rtx insn)
{
- int is_call = CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0;
- rtx handlers, i;
+ eh_landing_pad lp = get_eh_landing_pad_from_rtx (insn);
- handlers = reachable_handlers (insn);
+ if (lp)
+ {
+ rtx label = lp->landing_pad;
- for (i = handlers; i; i = XEXP (i, 1))
- make_label_edge (edge_cache, src, XEXP (i, 0),
- EDGE_ABNORMAL | EDGE_EH | is_call);
+ /* During initial rtl generation, use the post_landing_pad. */
+ if (label == NULL)
+ {
+ gcc_assert (lp->post_landing_pad);
+ label = label_rtx (lp->post_landing_pad);
+ }
- free_INSN_LIST_list (&handlers);
+ make_label_edge (edge_cache, src, label,
+ EDGE_ABNORMAL | EDGE_EH
+ | (CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0));
+ }
}
/* States of basic block as seen by find_many_sub_basic_blocks. */
{
rtx tmp;
- /* Recognize exception handling placeholders. */
- if (GET_CODE (PATTERN (insn)) == RESX)
- rtl_make_eh_edge (edge_cache, bb, insn);
-
/* Recognize a non-local goto as a branch outside the
current function. */
- else if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
+ if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
;
/* Recognize a tablejump and do the right thing. */
else if (returnjump_p (insn))
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0);
+ /* Recognize asm goto and do the right thing. */
+ else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL)
+ {
+ int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp);
+ for (i = 0; i < n; ++i)
+ make_label_edge (edge_cache, bb,
+ XEXP (ASM_OPERANDS_LABEL (tmp, i), 0), 0);
+ }
+
/* Otherwise, we have a plain conditional or unconditional jump. */
else
{
handler for this CALL_INSN. If we're handling non-call
exceptions then any insn can reach any of the active handlers.
Also mark the CALL_INSN as reaching any nonlocal goto handler. */
- else if (code == CALL_INSN || flag_non_call_exceptions)
+ else if (code == CALL_INSN || cfun->can_throw_non_call_exceptions)
{
/* Add any appropriate EH edges. */
rtl_make_eh_edge (edge_cache, bb, insn);
- if (code == CALL_INSN && nonlocal_goto_handler_labels)
+ if (code == CALL_INSN)
{
- /* ??? This could be made smarter: in some cases it's possible
- to tell that certain calls will not do a nonlocal goto.
- For example, if the nested functions that do the nonlocal
- gotos do not have their addresses taken, then only calls to
- those functions or to other nested functions that use them
- could possibly do nonlocal gotos. */
-
- /* We do know that a REG_EH_REGION note with a value less
- than 0 is guaranteed not to perform a non-local goto. */
- rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
-
- if (!note || INTVAL (XEXP (note, 0)) >= 0)
- for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1))
- make_label_edge (edge_cache, bb, XEXP (x, 0),
- EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
+ if (can_nonlocal_goto (insn))
+ {
+ /* ??? This could be made smarter: in some cases it's
+ possible to tell that certain calls will not do a
+ nonlocal goto. For example, if the nested functions
+ that do the nonlocal gotos do not have their addresses
+ taken, then only calls to those functions or to other
+ nested functions that use them could possibly do
+ nonlocal gotos. */
+ for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1))
+ make_label_edge (edge_cache, bb, XEXP (x, 0),
+ EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
+ }
+
+ if (flag_tm)
+ {
+ rtx note;
+ for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_TM)
+ make_label_edge (edge_cache, bb, XEXP (note, 0),
+ EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
+ }
}
}
{
enum rtx_code code = GET_CODE (insn);
- /* On code label, split current basic block. */
- if (code == CODE_LABEL)
+ /* In case we've previously seen an insn that effects a control
+ flow transfer, split the block. */
+ if ((flow_transfer_insn || code == CODE_LABEL)
+ && inside_basic_block_p (insn))
{
fallthru = split_block (bb, PREV_INSN (insn));
if (flow_transfer_insn)
bb = fallthru->dest;
remove_edge (fallthru);
flow_transfer_insn = NULL_RTX;
- if (LABEL_ALT_ENTRY_P (insn))
+ if (code == CODE_LABEL && LABEL_ALT_ENTRY_P (insn))
make_edge (ENTRY_BLOCK_PTR, bb, 0);
}
-
- /* In case we've previously seen an insn that effects a control
- flow transfer, split the block. */
- if (flow_transfer_insn && inside_basic_block_p (insn))
+ else if (code == BARRIER)
{
- fallthru = split_block (bb, PREV_INSN (insn));
- BB_END (bb) = flow_transfer_insn;
-
- /* Clean up the bb field for the insns between the blocks. */
- for (x = NEXT_INSN (flow_transfer_insn);
- x != BB_HEAD (fallthru->dest);
- x = NEXT_INSN (x))
- if (!BARRIER_P (x))
- set_block_for_insn (x, NULL);
-
- bb = fallthru->dest;
- remove_edge (fallthru);
- flow_transfer_insn = NULL_RTX;
+ /* __builtin_unreachable () may cause a barrier to be emitted in
+ the middle of a BB. We need to split it in the same manner as
+ if the barrier were preceded by a control_flow_insn_p insn. */
+ if (!flow_transfer_insn)
+ flow_transfer_insn = prev_nonnote_insn_bb (insn);
}
if (control_flow_insn_p (insn))
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