Fix PR17656

[Diego Novillo]

On Mon, 2004-10-18 at 13:48, Richard Henderson wrote:
> On Mon, Oct 18, 2004 at 01:37:17PM -0400, Diego Novillo wrote:
> >  	  fold_stmt (&tmp);
> >  	  if (tmp != stmt)
> ...
> > +		    fold_stmt (bsi_stmt_ptr (si));
> 
> Why are you re-folding?  Can't you bsi_replace with tmp?
> 
bsi_replace also seems to work.  I have also renamed stmt_for_bsi into
something more meaningful.


Diego.

	* tree-cfg.c (bsi_for_stmt): Rename from stmt_for_bsi.
	Update all callers.
	* tree-ssa.c (replace_immediate_uses): Call bsi_for_stmt.
	Don't call fold_stmt more than once, use bsi_replace.


Index: lambda-code.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/lambda-code.c,v
retrieving revision 2.13
diff -d -c -p -u -r2.13 lambda-code.c
--- lambda-code.c	6 Oct 2004 19:40:54 -0000	2.13
+++ lambda-code.c	18 Oct 2004 17:54:35 -0000
@@ -1937,7 +1937,7 @@ lambda_loopnest_to_gcc_loopnest (struct 
 		  LBV_COEFFICIENTS (lbv)[i] = 1;
 		  lbv = lambda_body_vector_compute_new (transform, lbv);
 		  newiv = lbv_to_gcc_expression (lbv, new_ivs, &stmts);
-		  bsi = stmt_for_bsi (stmt);
+		  bsi = bsi_for_stmt (stmt);
 		  /* Insert the statements to build that
 		     expression.  */
 		  bsi_insert_before (&bsi, stmts, BSI_SAME_STMT);
Index: tree-cfg.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-cfg.c,v
retrieving revision 2.78
diff -d -c -p -u -r2.78 tree-cfg.c
--- tree-cfg.c	16 Oct 2004 16:58:59 -0000	2.78
+++ tree-cfg.c	18 Oct 2004 17:54:35 -0000
@@ -2638,7 +2638,7 @@ set_bb_for_stmt (tree t, basic_block bb)
 /* Finds iterator for STMT.  */
 
 extern block_stmt_iterator
-stmt_for_bsi (tree stmt)
+bsi_for_stmt (tree stmt)
 {
   block_stmt_iterator bsi;
 
Index: tree-flow.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-flow.h,v
retrieving revision 2.52
diff -d -c -p -u -r2.52 tree-flow.h
--- tree-flow.h	7 Oct 2004 23:31:04 -0000	2.52
+++ tree-flow.h	18 Oct 2004 17:54:35 -0000
@@ -416,7 +416,7 @@ typedef struct {
 static inline block_stmt_iterator bsi_start (basic_block);
 static inline block_stmt_iterator bsi_last (basic_block);
 static inline block_stmt_iterator bsi_after_labels (basic_block);
-block_stmt_iterator stmt_for_bsi (tree);
+block_stmt_iterator bsi_for_stmt (tree);
 static inline bool bsi_end_p (block_stmt_iterator);
 static inline void bsi_next (block_stmt_iterator *);
 static inline void bsi_prev (block_stmt_iterator *);
Index: tree-ssa-loop-ivopts.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-loop-ivopts.c,v
retrieving revision 2.19
diff -d -c -p -u -r2.19 tree-ssa-loop-ivopts.c
--- tree-ssa-loop-ivopts.c	17 Oct 2004 23:13:21 -0000	2.19
+++ tree-ssa-loop-ivopts.c	18 Oct 2004 17:54:35 -0000
@@ -3878,7 +3878,7 @@ remove_statement (tree stmt, bool includ
     }
   else
     {
-      block_stmt_iterator bsi = stmt_for_bsi (stmt);
+      block_stmt_iterator bsi = bsi_for_stmt (stmt);
 
       bsi_remove (&bsi);
     }
@@ -3916,7 +3916,7 @@ rewrite_use_nonlinear_expr (struct ivopt
 
     case MODIFY_EXPR:
       tgt = TREE_OPERAND (use->stmt, 0);
-      bsi = stmt_for_bsi (use->stmt);
+      bsi = bsi_for_stmt (use->stmt);
       break;
 
     default:
@@ -4055,7 +4055,7 @@ rewrite_use_address (struct ivopts_data 
 {
   tree comp = unshare_expr (get_computation (data->current_loop,
 					     use, cand));
-  block_stmt_iterator bsi = stmt_for_bsi (use->stmt);
+  block_stmt_iterator bsi = bsi_for_stmt (use->stmt);
   tree stmts;
   tree op = force_gimple_operand (comp, &stmts, true, NULL_TREE);
 
@@ -4074,7 +4074,7 @@ rewrite_use_compare (struct ivopts_data 
 {
   tree comp;
   tree *op_p, cond, op, stmts, bound;
-  block_stmt_iterator bsi = stmt_for_bsi (use->stmt);
+  block_stmt_iterator bsi = bsi_for_stmt (use->stmt);
   enum tree_code compare;
   
   if (may_eliminate_iv (data->current_loop,
Index: tree-ssa.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa.c,v
retrieving revision 2.48
diff -d -c -p -u -r2.48 tree-ssa.c
--- tree-ssa.c	18 Oct 2004 17:39:39 -0000	2.48
+++ tree-ssa.c	18 Oct 2004 17:54:36 -0000
@@ -1105,20 +1105,9 @@ replace_immediate_uses (tree var, tree r
 	  fold_stmt (&tmp);
 	  if (tmp != stmt)
 	    {
-	      basic_block bb = bb_for_stmt (stmt);
-	      block_stmt_iterator si;
-
-	      /* Start iterating at the start of the basic block
-		 holding STMT until we reach it.  This is slow, but
-		 it's the only way to get a statement pointer
-		 reliably.  */
-	      for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
-		if (bsi_stmt (si) == stmt)
-		  {
-		    fold_stmt (bsi_stmt_ptr (si));
-		    stmt = bsi_stmt (si);
-		    break;
-		  }
+	      block_stmt_iterator si = bsi_for_stmt (stmt);
+	      bsi_replace (&si, tmp, true);
+	      stmt = bsi_stmt (si);
 	    }
 	}