re PR rtl-optimization/17931 (andl and testb are not combined)

	PR rtl-optimization/17931
	* config/i386/i386.c (ix86_rtx_costs): Handle COMPARE with
	ZERO_EXTRACT in it.

From-SVN: r88943

gcc/ChangeLog

+2004-10-12  Kazu Hirata  <kazu@cs.umass.edu>
+
+	PR rtl-optimization/17931
+	* config/i386/i386.c (ix86_rtx_costs): Handle COMPARE with
+	ZERO_EXTRACT in it.
+
 2004-10-12  Richard Earnshaw  <rearnsha@arm.com>
 
 	* arm.c (arm_print_operand): Use output_operand_lossage where possible

gcc/config/i386/i386.c

@@ -14326,6 +14326,21 @@ ix86_rtx_costs (rtx x, int code, int outer_code, int *total)
 	*total = COSTS_N_INSNS (ix86_cost->add);
       return false;
 
+    case COMPARE:
+      if (GET_CODE (XEXP (x, 0)) == ZERO_EXTRACT
+	  && XEXP (XEXP (x, 0), 1) == const1_rtx
+	  && GET_CODE (XEXP (XEXP (x, 0), 2)) == CONST_INT
+	  && XEXP (x, 1) == const0_rtx)
+	{
+	  /* This kind of construct is implemented using test[bwl].
+	     Treat it as if we had an AND.  */
+	  *total = (COSTS_N_INSNS (ix86_cost->add)
+		    + rtx_cost (XEXP (XEXP (x, 0), 0), outer_code)
+		    + rtx_cost (const1_rtx, outer_code));
+	  return true;
+	}
+      return false;
+
     case FLOAT_EXTEND:
       if (!TARGET_SSE_MATH || !VALID_SSE_REG_MODE (mode))
 	*total = 0;