Re: [PATCH] Fix up go regressions caused by my recent switchconv changes (PR go/91617)

[Jakub Jelinek <jakub@redhat.com>]

On Sun, Sep 01, 2019 at 06:44:15PM +0200, Richard Biener wrote:
> On September 1, 2019 6:34:25 PM GMT+02:00, Jakub Jelinek <jakub@redhat.com> wrote:
> >On Sat, Aug 31, 2019 at 08:25:49PM +0200, Richard Biener wrote:
> >> So why not always return an unsigned type then by telling
> >type_for_size? 
> >
> >So like this (if it passes bootstrap/regtest)?
> 
> Yes. 

Unfortunately that didn't work, because TYPE_MAX_VALUE/TYPE_MIN_VALUE
are not present on POINTER_TYPEs.

Here is an updated version that passed bootstrap/regtest on both
x86_64-linux and i686-linux, ok for trunk?

2019-09-02  Jakub Jelinek  <jakub@redhat.com>

	PR go/91617
	* fold-const.c (range_check_type): For enumeral and boolean
	type, pass 1 to type_for_size langhook instead of
	TYPE_UNSIGNED (etype).  Return unsigned_type_for result whenever
	etype isn't TYPE_UNSIGNED INTEGER_TYPE.
	(build_range_check): Don't call unsigned_type_for for pointer types.
	* match.pd (X / C1 op C2): Don't call unsigned_type_for on
	range_check_type result.

--- gcc/fold-const.c.jj	2019-08-27 22:52:24.207334541 +0200
+++ gcc/fold-const.c	2019-09-01 22:46:17.091058145 +0200
@@ -4938,10 +4938,9 @@ range_check_type (tree etype)
   /* First make sure that arithmetics in this type is valid, then make sure
      that it wraps around.  */
   if (TREE_CODE (etype) == ENUMERAL_TYPE || TREE_CODE (etype) == BOOLEAN_TYPE)
-    etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
-					    TYPE_UNSIGNED (etype));
+    etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype), 1);
 
-  if (TREE_CODE (etype) == INTEGER_TYPE && !TYPE_OVERFLOW_WRAPS (etype))
+  if (TREE_CODE (etype) == INTEGER_TYPE && !TYPE_UNSIGNED (etype))
     {
       tree utype, minv, maxv;
 
@@ -4959,6 +4958,8 @@ range_check_type (tree etype)
       else
 	return NULL_TREE;
     }
+  else if (POINTER_TYPE_P (etype))
+    etype = unsigned_type_for (etype);
   return etype;
 }
 
@@ -5049,9 +5050,6 @@ build_range_check (location_t loc, tree
   if (etype == NULL_TREE)
     return NULL_TREE;
 
-  if (POINTER_TYPE_P (etype))
-    etype = unsigned_type_for (etype);
-
   high = fold_convert_loc (loc, etype, high);
   low = fold_convert_loc (loc, etype, low);
   exp = fold_convert_loc (loc, etype, exp);
--- gcc/match.pd.jj	2019-08-27 12:26:40.745863588 +0200
+++ gcc/match.pd	2019-09-01 18:23:02.098729356 +0200
@@ -1569,8 +1569,6 @@ (define_operator_list COND_TERNARY
 	tree etype = range_check_type (TREE_TYPE (@0));
 	if (etype)
 	  {
-	    if (! TYPE_UNSIGNED (etype))
-	      etype = unsigned_type_for (etype);
 	    hi = fold_convert (etype, hi);
 	    lo = fold_convert (etype, lo);
 	    hi = const_binop (MINUS_EXPR, etype, hi, lo);


	Jakub