loop.c (insert_bct): Replace use of sdiv_optab with asr_optab and delete comment…

loop.c (insert_bct): Replace use of sdiv_optab with asr_optab and delete comment that code should be...

        * loop.c (insert_bct): Replace use of sdiv_optab with asr_optab
        and delete comment that code should be rewritten.

From-SVN: r28839

gcc/ChangeLog

+Tue Aug 24 23:26:44 1999  Michael Tiemann  <tiemann@holodeck.cygnus.com>
+
+	* loop.c (insert_bct): Replace use of sdiv_optab with asr_optab
+	and delete comment that code should be rewritten.
+
 Tue Aug 24 22:56:35 1999  Jeffrey A Law  (law@cygnus.com)
 
 	* haifa-sched.c (find_rgns): Mark a block found during the DFS search

gcc/loop.c

@@ -9235,19 +9235,10 @@ insert_bct (loop_start, loop_end, loop_info)
 				   NULL_RTX, 0, OPTAB_LIB_WIDEN);
 
 	if (increment_value_abs != 1)
-	  {
-	    /* ??? This will generate an expensive divide instruction for
-	       most targets.  The original authors apparently expected this
-	       to be a shift, since they test for power-of-2 divisors above,
-	       but just naively generating a divide instruction will not give 
-	       a shift.  It happens to work for the PowerPC target because
-	       the rs6000.md file has a divide pattern that emits shifts.
-	       It will probably not work for any other target.  */
-	    iterations_num_reg = expand_binop (loop_var_mode, sdiv_optab,
-					       temp_reg,
-					       GEN_INT (increment_value_abs),
-					       NULL_RTX, 0, OPTAB_LIB_WIDEN);
-	  }
+	  iterations_num_reg = expand_binop (loop_var_mode, asr_optab,
+					     temp_reg,
+					     GEN_INT (exact_log2 (increment_value_abs)),
+					     NULL_RTX, 0, OPTAB_LIB_WIDEN);
 	else
 	  iterations_num_reg = temp_reg;
       }