CbC/CbC_gcc: gcc/cfgbuild.c comparison

comparison gcc/cfgbuild.c @ 55:77e2b8dfacca gcc-4.4.5

update it from 4.4.3 to 4.5.0

author	ryoma <e075725@ie.u-ryukyu.ac.jp>
date	Fri, 12 Feb 2010 23:39:51 +0900
parents	a06113de4d67
children	b7f97abdc517

comparison

equal deleted inserted replaced

-:c156f1bd5cd9
+:77e2b8dfacca
 You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
-/* find_basic_blocks divides the current function's rtl into basic
-blocks and constructs the CFG.  The blocks are recorded in the
-basic_block_info array; the CFG exists in the edge structures
-referenced by the blocks.
-find_basic_blocks also finds any unreachable loops and deletes them.
-Available functionality:
-- CFG construction
-	 find_basic_blocks  */
 #include "config.h"
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
 #include "regs.h"
 #include "flags.h"
 #include "output.h"
 #include "function.h"
 #include "except.h"
+#include "expr.h"
 #include "toplev.h"
 #include "timevar.h"
-static int count_basic_blocks (const_rtx);
-static void find_basic_blocks_1 (rtx);
 static void make_edges (basic_block, basic_block, int);
 static void make_label_edge (sbitmap, basic_block, rtx, int);
 static void find_bb_boundaries (basic_block);
 static void compute_outgoing_frequencies (basic_block);
 return (GET_CODE (PATTERN (insn)) != ADDR_VEC
 	      && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
 case CALL_INSN:
 case INSN:
+case DEBUG_INSN:
 return true;
 case BARRIER:
 case NOTE:
 return false;
 the basic block.  */
 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:
 /* Jump insn always causes control transfer except for tablejumps.  */
 return (GET_CODE (PATTERN (insn)) != ADDR_VEC
 	 (but only if they happen unconditionally).  */
 if ((SIBLING_CALL_P (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
+if (can_nonlocal_goto (insn))
-	       && (0 == (note = find_reg_note (insn, REG_EH_REGION,
+	return true;
-					       NULL_RTX))
+break;
-		   || INTVAL (XEXP (note, 0)) >= 0))
-	      /* Or may trap.  */
-	      || can_throw_internal (insn));
 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;
+if (!flag_non_call_exceptions)
-return (flag_non_call_exceptions && can_throw_internal (insn));
+	return false;
+break;
 case BARRIER:
 /* It is nonsense to reach barrier when looking for the
 	 end of basic block, but before dead code is eliminated
 	 this may happen.  */
 return false;
 default:
 gcc_unreachable ();
 }
-}
+return can_throw_internal (insn);
-/* Count the basic blocks of the function.  */
+}
-static int
-count_basic_blocks (const_rtx f)
-{
-int count = NUM_FIXED_BLOCKS;
-bool saw_insn = false;
-const_rtx insn;
-for (insn = f; insn; insn = NEXT_INSN (insn))
-{
-/* Code labels and barriers causes current basic block to be
-	 terminated at previous real insn.  */
-if ((LABEL_P (insn) || BARRIER_P (insn))
-	  && saw_insn)
-	count++, saw_insn = false;
-/* Start basic block if needed.  */
-if (!saw_insn && inside_basic_block_p (insn))
-	saw_insn = true;
-/* Control flow insn causes current basic block to be terminated.  */
-if (saw_insn && control_flow_insn_p (insn))
-	count++, saw_insn = false;
-}
-if (saw_insn)
-count++;
-/* The rest of the compiler works a bit smoother when we don't have to
-check for the edge case of do-nothing functions with no basic blocks.  */
-if (count == NUM_FIXED_BLOCKS)
-{
-emit_use (const0_rtx);
-count = NUM_FIXED_BLOCKS + 1;
-}
-return count;
-}
 /* Create an edge between two basic blocks.  FLAGS are auxiliary information
 about the edge that is accumulated between calls.  */
 /* Create an edge from a basic block to a label.  */
 /* Create the edges generated by INSN in REGION.  */
 void
 rtl_make_eh_edge (sbitmap edge_cache, basic_block src, rtx insn)
 {
-int is_call = CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0;
+eh_landing_pad lp = get_eh_landing_pad_from_rtx (insn);
-rtx handlers, i;
+if (lp)
-handlers = reachable_handlers (insn);
+{
+rtx label = lp->landing_pad;
-for (i = handlers; i; i = XEXP (i, 1))
-make_label_edge (edge_cache, src, XEXP (i, 0),
+/* During initial rtl generation, use the post_landing_pad.  */
-		     EDGE_ABNORMAL | EDGE_EH | is_call);
+if (label == NULL)
+	{
-free_INSN_LIST_list (&handlers);
+	  gcc_assert (lp->post_landing_pad);
+	  label = label_rtx (lp->post_landing_pad);
+	}
+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.  */
 enum state {
 /* Basic blocks created via split_block belong to this state.
 /* A branch.  */
 if (code == JUMP_INSN)
 	{
 	  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 (tablejump_p (insn, NULL, &tmp))
 	    {
 	  /* Returns create an exit out.  */
 	  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
 	    {
 	      gcc_assert (JUMP_LABEL (insn));
 	      make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0);
 		 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.  */
+	      if (can_nonlocal_goto (insn))
-	      /* 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 (edge_cache)
 sbitmap_vector_free (edge_cache);
-}
-/* Find all basic blocks of the function whose first insn is F.
-Collect and return a list of labels whose addresses are taken.  This
-will be used in make_edges for use with computed gotos.  */
-static void
-find_basic_blocks_1 (rtx f)
-{
-rtx insn, next;
-rtx bb_note = NULL_RTX;
-rtx head = NULL_RTX;
-rtx end = NULL_RTX;
-basic_block prev = ENTRY_BLOCK_PTR;
-/* We process the instructions in a slightly different way than we did
-previously.  This is so that we see a NOTE_BASIC_BLOCK after we have
-closed out the previous block, so that it gets attached at the proper
-place.  Since this form should be equivalent to the previous,
-count_basic_blocks continues to use the old form as a check.  */
-for (insn = f; insn; insn = next)
-{
-enum rtx_code code = GET_CODE (insn);
-next = NEXT_INSN (insn);
-if ((LABEL_P (insn) || BARRIER_P (insn))
-	  && head)
-	{
-	  prev = create_basic_block_structure (head, end, bb_note, prev);
-	  head = end = NULL_RTX;
-	  bb_note = NULL_RTX;
-	}
-if (inside_basic_block_p (insn))
-	{
-	  if (head == NULL_RTX)
-	    head = insn;
-	  end = insn;
-	}
-if (head && control_flow_insn_p (insn))
-	{
-	  prev = create_basic_block_structure (head, end, bb_note, prev);
-	  head = end = NULL_RTX;
-	  bb_note = NULL_RTX;
-	}
-switch (code)
-	{
-	case NOTE:
-	  /* Look for basic block notes with which to keep the
-	     basic_block_info pointers stable.  Unthread the note now;
-	     we'll put it back at the right place in create_basic_block.
-	     Or not at all if we've already found a note in this block.  */
-	  if (NOTE_INSN_BASIC_BLOCK_P (insn))
-	    {
-	      if (bb_note == NULL_RTX)
-		bb_note = insn;
-	      else
-		next = delete_insn (insn);
-	    }
-	  break;
-	case CODE_LABEL:
-	case JUMP_INSN:
-	case CALL_INSN:
-	case INSN:
-	case BARRIER:
-	  break;
-	default:
-	  gcc_unreachable ();
-	}
-}
-if (head != NULL_RTX)
-create_basic_block_structure (head, end, bb_note, prev);
-else if (bb_note)
-delete_insn (bb_note);
-gcc_assert (last_basic_block == n_basic_blocks);
-clear_aux_for_blocks ();
-}
-/* Find basic blocks of the current function.
-F is the first insn of the function.  */
-void
-find_basic_blocks (rtx f)
-{
-basic_block bb;
-timevar_push (TV_CFG);
-/* Flush out existing data.  */
-if (basic_block_info != NULL)
-{
-clear_edges ();
-/* Clear bb->aux on all extant basic blocks.  We'll use this as a
-	 tag for reuse during create_basic_block, just in case some pass
-	 copies around basic block notes improperly.  */
-FOR_EACH_BB (bb)
-	bb->aux = NULL;
-basic_block_info = NULL;
-}
-n_basic_blocks = count_basic_blocks (f);
-last_basic_block = NUM_FIXED_BLOCKS;
-ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
-EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
-/* Size the basic block table.  The actual structures will be allocated
-by find_basic_blocks_1, since we want to keep the structure pointers
-stable across calls to find_basic_blocks.  */
-/* ??? This whole issue would be much simpler if we called find_basic_blocks
-exactly once, and thereafter we don't have a single long chain of
-instructions at all until close to the end of compilation when we
-actually lay them out.  */
-basic_block_info = VEC_alloc (basic_block, gc, n_basic_blocks);
-VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
-SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
-SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
-find_basic_blocks_1 (f);
-profile_status = PROFILE_ABSENT;
-/* Tell make_edges to examine every block for out-going edges.  */
-FOR_EACH_BB (bb)
-SET_STATE (bb, BLOCK_NEW);
-/* Discover the edges of our cfg.  */
-make_edges (ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, 0);
-/* Do very simple cleanup now, for the benefit of code that runs between
-here and cleanup_cfg, e.g. thread_prologue_and_epilogue_insns.  */
-tidy_fallthru_edges ();
-#ifdef ENABLE_CHECKING
-verify_flow_info ();
-#endif
-timevar_pop (TV_CFG);
 }
 static void
 mark_tablejump_edge (rtx label)
 {
 /* Scan insn chain and try to find new basic block boundaries.  */
 while (1)
 {
 enum rtx_code code = GET_CODE (insn);
-/* On code label, split current basic block.  */
+/* In case we've previously seen an insn that effects a control
-if (code == CODE_LABEL)
+	 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_END (bb) = 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);
 	}
+else if (code == BARRIER)
-/* In case we've previously seen an insn that effects a control
+	{
-	 flow transfer, split the block.  */
+	  /* __builtin_unreachable () may cause a barrier to be emitted in
-if (flow_transfer_insn && inside_basic_block_p (insn))
+	     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.  */
-	  fallthru = split_block (bb, PREV_INSN (insn));
+	  if (!flow_transfer_insn)
-	  BB_END (bb) = flow_transfer_insn;
+	    flow_transfer_insn = prev_nonnote_insn_bb (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;
 	}
 if (control_flow_insn_p (insn))
 	flow_transfer_insn = insn;
 if (insn == end)

Mercurial > hg > CbC > CbC_gcc

comparison gcc/cfgbuild.c @ 55:77e2b8dfacca gcc-4.4.5