emit-rtl.c (subreg_hard_regno): Check that register is representable.

	* emit-rtl.c (subreg_hard_regno):  Check that register is representable.
	* reload.c (reload_inner_reg_of_subreg):  When register is not
	representable, reload the whole thing.
	(find_reloads): Likewsie.
	* rtlanal.c (subreg_representable_p):  New function.

	* profile.c (compute_branch_probabilities):  Cleanup sanity checking;
	allow negative probabilities for edges from the call to exit.
	(branch_prob): Do not add fake edges for functions that may return twice

From-SVN: r65757

gcc/ChangeLog

+Fri Apr 18 01:28:51 CEST 2003  Jan Hubicka  <jh@suse.cz>
+
+	* emit-rtl.c (subreg_hard_regno):  Check that register is representable.
+	* reload.c (reload_inner_reg_of_subreg):  When register is not
+	representable, reload the whole thing.
+	(find_reloads): Likewsie.
+	* rtlanal.c (subreg_representable_p):  New function.
+
+	* profile.c (compute_branch_probabilities):  Cleanup sanity checking;
+	allow negative probabilities for edges from the call to exit.
+	(branch_prob): Do not add fake edges for functions that may return twice
+
 2003-04-17  DJ Delorie  <dj@redhat.com>
 
 	* toplev.c (target_options): Add value field.

gcc/emit-rtl.c

@@ -1081,7 +1081,11 @@ subreg_hard_regno (x, check_mode)
     abort ();
   if (check_mode && ! HARD_REGNO_MODE_OK (base_regno, GET_MODE (reg)))
     abort ();
-
+#ifdef ENABLE_CHECKING
+  if (!subreg_offset_representable_p (REGNO (reg), GET_MODE (reg),
+			  	      SUBREG_BYTE (x), mode))
+    abort ();
+#endif
   /* Catch non-congruent offsets too.  */
   byte_offset = SUBREG_BYTE (x);
   if ((byte_offset % GET_MODE_SIZE (mode)) != 0)

gcc/profile.c

@@ -674,22 +674,47 @@ compute_branch_probabilities ()
   FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
     {
       edge e;
-      gcov_type total;
       rtx note;
 
-      total = bb->count;
-      if (total)
+      if (bb->count < 0)
 	{
-	  for (e = bb->succ; e; e = e->succ_next)
+	  error ("corrupted profile info: number of iterations for basic block %d thought to be %i",
+		 bb->index, (int)bb->count);
+	  bb->count = 0;
+	}
+      for (e = bb->succ; e; e = e->succ_next)
+	{
+	  /* Function may return twice in the cased the called fucntion is
+	     setjmp or calls fork, but we can't represent this by extra
+	     edge from the entry, since extra edge from the exit is
+	     already present.  We get negative frequency from the entry
+	     point.  */
+	  if ((e->count < 0
+	       && e->dest == EXIT_BLOCK_PTR)
+	      || (e->count > bb->count
+		  && e->dest != EXIT_BLOCK_PTR))
 	    {
-		e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total;
-		if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
-		  {
-		    error ("corrupted profile info: prob for %d-%d thought to be %d",
-			   e->src->index, e->dest->index, e->probability);
-		    e->probability = REG_BR_PROB_BASE / 2;
-		  }
+	      rtx insn = bb->end;
+
+	      while (GET_CODE (insn) != CALL_INSN
+		     && insn != bb->head
+		     && keep_with_call_p (insn))
+		insn = PREV_INSN (insn);
+	      if (GET_CODE (insn) == CALL_INSN)
+		e->count = e->count < 0 ? 0 : bb->count;
 	    }
+	  if (e->count < 0 || e->count > bb->count)
+	    {
+	      error ("corrupted profile info: number of executions for edge %d-%d thought to be %i",
+		     e->src->index, e->dest->index,
+		     (int)e->count);
+	      e->count = bb->count / 2;
+	    }
+	}
+      if (bb->count)
+	{
+	  for (e = bb->succ; e; e = e->succ_next)
+	    e->probability = (e->count * REG_BR_PROB_BASE + bb->count / 2) / bb->count;
 	  if (bb->index >= 0
 	      && any_condjump_p (bb->end)
 	      && bb->succ->succ_next)
@@ -730,6 +755,8 @@ compute_branch_probabilities ()
 	 calls).  */
       else
 	{
+	  int total = 0;
+
 	  for (e = bb->succ; e; e = e->succ_next)
 	    if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
 	      total ++;
@@ -873,36 +900,13 @@ branch_prob ()
     {
       int need_exit_edge = 0, need_entry_edge = 0;
       int have_exit_edge = 0, have_entry_edge = 0;
-      rtx insn;
       edge e;
 
-      /* Add fake edges from entry block to the call insns that may return
-	 twice.  The CFG is not quite correct then, as call insn plays more
-	 role of CODE_LABEL, but for our purposes, everything should be OK,
-	 as we never insert code to the beginning of basic block.  */
-      for (insn = bb->head; insn != NEXT_INSN (bb->end);
-	   insn = NEXT_INSN (insn))
-	{
-	  if (GET_CODE (insn) == CALL_INSN
-	      && find_reg_note (insn, REG_SETJMP, NULL))
-	    {
-	      if (GET_CODE (bb->head) == CODE_LABEL
-		  || insn != NEXT_INSN (bb->head))
-		{
-		  e = split_block (bb, PREV_INSN (insn));
-		  make_edge (ENTRY_BLOCK_PTR, e->dest, EDGE_FAKE);
-		  break;
-		}
-	      else
-		{
-		  /* We should not get abort here, as call to setjmp should not
-		     be the very first instruction of function.  */
-		  if (bb == ENTRY_BLOCK_PTR)
-		    abort ();
-		  make_edge (ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
-		}
-	    }
-	}
+      /* Functions returning multiple times are not handled by extra edges.
+         Instead we simply allow negative counts on edges from exit to the
+         block past call and corresponding probabilities.  We can't go
+         with the extra edges because that would result in flowgraph that
+	 needs to have fake edges outside the spanning tree.  */
 
       for (e = bb->succ; e; e = e->succ_next)
 	{

gcc/reload.c

@@ -2880,6 +2880,12 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p)
 	      if (GET_CODE (SUBREG_REG (operand)) == REG
 		  && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
 		{
+		  if (!subreg_offset_representable_p
+			(REGNO (SUBREG_REG (operand)),
+			 GET_MODE (SUBREG_REG (operand)),
+			 SUBREG_BYTE (operand),
+			 GET_MODE (operand)))
+		     force_reload = 1;
 		  offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
 						 GET_MODE (SUBREG_REG (operand)),
 						 SUBREG_BYTE (operand),
@@ -2935,26 +2941,6 @@ find_reloads (insn, replace, ind_levels, live_known, reload_reg_p)
 			  )
 #endif
 		      )
-		  /* This following hunk of code should no longer be
-		     needed at all with SUBREG_BYTE.  If you need this
-		     code back, please explain to me why so I can
-		     fix the real problem.  -DaveM */
-#if 0
-		  /* Subreg of a hard reg which can't handle the subreg's mode
-		     or which would handle that mode in the wrong number of
-		     registers for subregging to work.  */
-		  || (GET_CODE (operand) == REG
-		      && REGNO (operand) < FIRST_PSEUDO_REGISTER
-		      && ((GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
-			   && (GET_MODE_SIZE (GET_MODE (operand))
-			       > UNITS_PER_WORD)
-			   && ((GET_MODE_SIZE (GET_MODE (operand))
-				/ UNITS_PER_WORD)
-			       != HARD_REGNO_NREGS (REGNO (operand),
-						    GET_MODE (operand))))
-			  || ! HARD_REGNO_MODE_OK (REGNO (operand) + offset,
-						   operand_mode[i])))
-#endif
 		  )
 		force_reload = 1;
 	    }
@@ -5272,6 +5258,19 @@ find_reloads_address_1 (mode, x, context, loc, opnum, type, ind_levels, insn)
 						       SUBREG_BYTE (orig_op1),
 						       GET_MODE (orig_op1))));
 	  }
+	/* Plus in the index register may be created only as a result of
+	   register remateralization for expresion like &localvar*4.  Reload it.
+	   It may be possible to combine the displacement on the outer level,
+	   but it is probably not worthwhile to do so.  */
+	if (context)
+	  {
+	    find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
+				  opnum, ADDR_TYPE (type), ind_levels, insn);
+	    push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
+			 (context ? INDEX_REG_CLASS : MODE_BASE_REG_CLASS (mode)),
+			 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
+	    return 1;
+	  }
 
 	if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
 	    || code0 == ZERO_EXTEND || code1 == MEM)

gcc/rtl.h

@@ -1038,6 +1038,10 @@ extern unsigned int subreg_regno_offset 	PARAMS ((unsigned int,
 							 enum machine_mode, 
 							 unsigned int, 
 							 enum machine_mode));
+extern bool subreg_offset_representable_p 	PARAMS ((unsigned int, 
+							 enum machine_mode, 
+							 unsigned int, 
+							 enum machine_mode));
 extern unsigned int subreg_regno 	PARAMS ((rtx));
 
 /* 1 if RTX is a subreg containing a reg that is already known to be

gcc/rtlanal.c

@@ -3387,6 +3387,77 @@ subreg_regno_offset (xregno, xmode, offset, ymode)
   return (y_offset / (mode_multiple / nregs_multiple)) * nregs_ymode;
 }
 
+/* This function returns true when the offset is representable via
+   subreg_offset in the given regno.
+   xregno - A regno of an inner hard subreg_reg (or what will become one).
+   xmode  - The mode of xregno.
+   offset - The byte offset.
+   ymode  - The mode of a top level SUBREG (or what may become one).
+   RETURN - The regno offset which would be used.  */
+bool
+subreg_offset_representable_p (xregno, xmode, offset, ymode)
+     unsigned int xregno;
+     enum machine_mode xmode;
+     unsigned int offset;
+     enum machine_mode ymode;
+{
+  int nregs_xmode, nregs_ymode;
+  int mode_multiple, nregs_multiple;
+  int y_offset;
+
+  if (xregno >= FIRST_PSEUDO_REGISTER)
+    abort ();
+
+  nregs_xmode = HARD_REGNO_NREGS (xregno, xmode);
+  nregs_ymode = HARD_REGNO_NREGS (xregno, ymode);
+
+  /* paradoxical subregs are always valid.  */
+  if (offset == 0
+      && nregs_ymode > nregs_xmode
+      && (GET_MODE_SIZE (ymode) > UNITS_PER_WORD
+	  ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN))
+    return true;
+
+  /* Lowpart subregs are always valid.  */
+  if (offset == subreg_lowpart_offset (ymode, xmode))
+    return true;
+
+#ifdef ENABLE_CHECKING
+  /* This should always pass, otherwise we don't know how to verify the
+     constraint. 
+
+     These conditions may be relaxed but subreg_offset would need to be
+     redesigned.  */
+  if (GET_MODE_SIZE (xmode) % GET_MODE_SIZE (ymode)
+      || GET_MODE_SIZE (ymode) % nregs_ymode
+      || mode_for_size (GET_MODE_SIZE (ymode) / nregs_ymode,
+	      		MODE_INT, 0) == VOIDmode
+      || nregs_xmode % nregs_ymode)
+    abort ();
+#endif
+
+  /* The XMODE value can be seen as an vector of NREGS_XMODE
+     values.  The subreg must represent an lowpart of given field.
+     Compute what field it is.  */
+  offset -= subreg_lowpart_offset (mode_for_size (GET_MODE_SIZE (ymode)
+			  			  / nregs_ymode,
+						  MODE_INT, 0), xmode);
+
+  /* size of ymode must not be greater than the size of xmode.  */
+  mode_multiple = GET_MODE_SIZE (xmode) / GET_MODE_SIZE (ymode);
+  if (mode_multiple == 0)
+    abort ();
+
+  y_offset = offset / GET_MODE_SIZE (ymode);
+  nregs_multiple =  nregs_xmode / nregs_ymode;
+#ifdef ENABLE_CHECKING
+  if (offset % GET_MODE_SIZE (ymode)
+      || mode_multiple % nregs_multiple)
+    abort ();
+#endif
+  return (!(y_offset % (mode_multiple / nregs_multiple)));
+}
+
 /* Return the final regno that a subreg expression refers to.  */
 unsigned int
 subreg_regno (x)