re PR rtl-optimization/10056 ([HP-PA] ICE at -O2 when building c++ code from doxygen)

	PR opt/10056
	* cfglayout.c (fixup_reorder_chain):  Fix dealing with the conditional
	jump jumping to the next instruction.
	* cfgrtl.c (force_nonfallthru_and_redirect):  Likewise.

From-SVN: r64854

3 files changed, 70 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2e6bc1cf..ff7624a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+Mon Mar 24 20:03:03 CET 2003  Jan Hubicka  <jh@suse.cz>
+
+	PR opt/10056
+	* cfglayout.c (fixup_reorder_chain):  Fix dealing with the conditional
+	jump jumping to the next instruction.
+	* cfgrtl.c (force_nonfallthru_and_redirect):  Likewise.
+
 2003-03-25  Gerald Pfeifer  <pfeifer@dbai.tuwien.ac.at>
 
 	* doc/passes.texi (Passes): Properly document that we do not
diff --git a/gcc/cfglayout.c b/gcc/cfglayout.c
index 1f4f8fc..c95ac38 100644
--- a/gcc/cfglayout.c
+++ b/gcc/cfglayout.c
@@ -465,11 +465,43 @@ fixup_reorder_chain ()
 		      && e_fall->dest == EXIT_BLOCK_PTR))
 		continue;
 
+	      /* The degenerated case of conditional jump jumping to the next
+		 instruction can happen on target having jumps with side
+		 effects.  
+
+		 Create temporarily the duplicated edge representing branch.
+		 It will get unidentified by force_nonfallthru_and_redirect
+		 that would otherwise get confused by fallthru edge not pointing
+		 to the next basic block.  */
+	      if (!e_taken)
+		{
+		  rtx note;
+		  edge e_fake;
+
+		  e_fake = unchecked_make_edge (bb, e_fall->dest, 0);
+
+		  if (!redirect_jump (bb->end, block_label (bb), 0))
+		    abort ();
+		  note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX);
+		  if (note)
+		    {
+		      int prob = INTVAL (XEXP (note, 0));
+
+		      e_fake->probability = prob;
+		      e_fake->count = e_fall->count * prob / REG_BR_PROB_BASE;
+		      e_fall->probability -= e_fall->probability;
+		      e_fall->count -= e_fake->count;
+		      if (e_fall->probability < 0)
+			e_fall->probability = 0;
+		      if (e_fall->count < 0)
+			e_fall->count = 0;
+		    }
+		}
 	      /* There is one special case: if *neither* block is next,
 		 such as happens at the very end of a function, then we'll
 		 need to add a new unconditional jump.  Choose the taken
 		 edge based on known or assumed probability.  */
-	      if (RBI (bb)->next != e_taken->dest)
+	      else if (RBI (bb)->next != e_taken->dest)
 		{
 		  rtx note = find_reg_note (bb_end_insn, REG_BR_PROB, 0);
 
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index 01b7e92..5e47236 100644
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -78,7 +78,7 @@ static void commit_one_edge_insertion	PARAMS ((edge, int));
 static bool try_redirect_by_replacing_jump PARAMS ((edge, basic_block));
 static rtx last_loop_beg_note		PARAMS ((rtx));
 static bool back_edge_of_syntactic_loop_p PARAMS ((basic_block, basic_block));
-static basic_block force_nonfallthru_and_redirect PARAMS ((edge, basic_block));
+basic_block force_nonfallthru_and_redirect PARAMS ((edge, basic_block));
 
 /* Return true if NOTE is not one of the ones that must be kept paired,
    so that we may simply delete it.  */
@@ -930,7 +930,7 @@ redirect_edge_and_branch (e, target)
 /* Like force_nonfallthru below, but additionally performs redirection
    Used by redirect_edge_and_branch_force.  */
 
-static basic_block
+basic_block
 force_nonfallthru_and_redirect (e, target)
      edge e;
      basic_block target;
@@ -940,6 +940,34 @@ force_nonfallthru_and_redirect (e, target)
   edge new_edge;
   int abnormal_edge_flags = 0;
 
+  /* In the case the last instruction is conditional jump to the next
+     instruction, first redirect the jump itself and then continue
+     by creating an basic block afterwards to redirect fallthru edge.  */
+  if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR
+      && any_condjump_p (e->src->end)
+      && JUMP_LABEL (e->src->end) == e->dest->head)
+    {
+      rtx note;
+      edge b = make_edge (e->src, target, 0);
+
+      if (!redirect_jump (e->src->end, block_label (target), 0))
+	abort ();
+      note = find_reg_note (e->src->end, REG_BR_PROB, NULL_RTX);
+      if (note)
+	{
+	  int prob = INTVAL (XEXP (note, 0));
+
+	  b->probability = prob;
+	  b->count = e->count * prob / REG_BR_PROB_BASE;
+	  e->probability -= e->probability;
+	  e->count -= b->count;
+	  if (e->probability < 0)
+	    e->probability = 0;
+	  if (e->count < 0)
+	    e->count = 0;
+	}
+    }
+
   if (e->flags & EDGE_ABNORMAL)
     {
       /* Irritating special case - fallthru edge to the same block as abnormal