genrecog.c tweak

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

This un-pessimizes the recent change to genrecog.c in that it only avoids
using a switch for a HOST_WIDE_INT value if the actual integer is too large.

Tested (along with the previous patch) on alphaev6.

Fri May 18 07:26:34 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>

	* genrecog.c (enum decision_type): Add DT_elt_zero-wide_safe.
	(add_to_sequence): Make that decision type.
	(maybe_both_true_2, nodes_identical_1, factor_tests): Use it.
	(write_switch, write_cond, debug_decision_2): Likewise.

*** genrecog.c	2001/05/09 10:06:20	1.97
--- genrecog.c	2001/05/18 20:49:35
*************** struct decision_test
*** 85,94 ****
  
    /* These types are roughly in the order in which we'd like to test them.  */
!   enum decision_type {
!     DT_mode, DT_code, DT_veclen,
!     DT_elt_zero_int, DT_elt_one_int, DT_elt_zero_wide,
!     DT_veclen_ge, DT_dup, DT_pred, DT_c_test, 
!     DT_accept_op, DT_accept_insn
!   } type;
  
    union
--- 85,95 ----
  
    /* These types are roughly in the order in which we'd like to test them.  */
!   enum decision_type
!     {
!       DT_mode, DT_code, DT_veclen,
!       DT_elt_zero_int, DT_elt_one_int, DT_elt_zero_wide, DT_elt_zero_wide_safe,
!       DT_veclen_ge, DT_dup, DT_pred, DT_c_test, 
!       DT_accept_op, DT_accept_insn
!     } type;
  
    union
*************** add_to_sequence (pattern, last, position
*** 957,964 ****
        else if (fmt[i] == 'w')
  	{
  	  if (i != 0)
  	    abort ();
  
! 	  test = new_decision_test (DT_elt_zero_wide, &place);
  	  test->u.intval = XWINT (pattern, i);
  	}
--- 958,971 ----
        else if (fmt[i] == 'w')
  	{
+ 	  /* If this value actually fits in an int, we can use a switch
+ 	     statement here, so indicate that.  */
+ 	  enum decision_type type
+ 	    = ((int) XWINT (pattern, i) == XWINT (pattern, i))
+ 	      ? DT_elt_zero_wide_safe : DT_elt_zero_wide;
+ 
  	  if (i != 0)
  	    abort ();
  
! 	  test = new_decision_test (type, &place);
  	  test->u.intval = XWINT (pattern, i);
  	}
*************** maybe_both_true_2 (d1, d2)
*** 1056,1059 ****
--- 1063,1067 ----
  	case DT_elt_one_int:
  	case DT_elt_zero_wide:
+ 	case DT_elt_zero_wide_safe:
  	  return d1->u.intval == d2->u.intval;
  
*************** nodes_identical_1 (d1, d2)
*** 1279,1282 ****
--- 1287,1291 ----
      case DT_elt_one_int:
      case DT_elt_zero_wide:
+     case DT_elt_zero_wide_safe:
        return d1->u.intval == d2->u.intval;
  
*************** factor_tests (head)
*** 1489,1493 ****
  	  && type != DT_elt_zero_int
  	  && type != DT_elt_one_int
! 	  && type != DT_elt_zero_wide)
  	continue;
  
--- 1498,1502 ----
  	  && type != DT_elt_zero_int
  	  && type != DT_elt_one_int
! 	  && type != DT_elt_zero_wide_safe)
  	continue;
  
*************** write_switch (start, depth)
*** 1859,1868 ****
  	   || type == DT_elt_zero_int
  	   || type == DT_elt_one_int
! 	   || type == DT_elt_zero_wide)
      {
-       /* The argument is casted to int.  In case HOST_WIDE_INT is more exact,
-          we can't safely construct switch statement over it.  */
-       if (type == DT_elt_zero_wide && HOST_BITS_PER_WIDE_INT > sizeof (int) * CHAR_BIT)
- 	  return p;
        printf ("  switch (");
        switch (type)
--- 1868,1873 ----
  	   || type == DT_elt_zero_int
  	   || type == DT_elt_one_int
! 	   || type == DT_elt_zero_wide_safe)
      {
        printf ("  switch (");
        switch (type)
*************** write_switch (start, depth)
*** 1880,1884 ****
  	  printf ("XINT (x%d, 1)", depth);
  	  break;
! 	case DT_elt_zero_wide:
  	  /* Convert result of XWINT to int for portability since some C
  	     compilers won't do it and some will.  */
--- 1885,1889 ----
  	  printf ("XINT (x%d, 1)", depth);
  	  break;
! 	case DT_elt_zero_wide_safe:
  	  /* Convert result of XWINT to int for portability since some C
  	     compilers won't do it and some will.  */
*************** write_switch (start, depth)
*** 1915,1918 ****
--- 1920,1924 ----
  	    case DT_elt_one_int:
  	    case DT_elt_zero_wide:
+ 	    case DT_elt_zero_wide_safe:
  	      printf (HOST_WIDE_INT_PRINT_DEC, p->tests->u.intval);
  	      break;
*************** write_cond (p, depth, subroutine_type)
*** 1971,1974 ****
--- 1977,1981 ----
  
      case DT_elt_zero_wide:
+     case DT_elt_zero_wide_safe:
        printf ("XWINT (x%d, 0) == ", depth);
        printf (HOST_WIDE_INT_PRINT_DEC, p->u.intval);
*************** debug_decision_2 (test)
*** 2741,2744 ****
--- 2748,2755 ----
      case DT_elt_zero_wide:
        fprintf (stderr, "elt0_w=");
+       fprintf (stderr, HOST_WIDE_INT_PRINT_DEC, test->u.intval);
+       break;
+     case DT_elt_zero_wide_safe:
+       fprintf (stderr, "elt0_ws=");
        fprintf (stderr, HOST_WIDE_INT_PRINT_DEC, test->u.intval);
        break;