[Bug tree-optimization/92644] [9/10 Regression] ICE in wide_int_to_tree_1, at tree.c:1530

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92644

--- Comment #5 from Jakub Jelinek  ---
Author: jakub
Date: Tue Nov 26 08:43:27 2019
New Revision: 278720

URL: https://gcc.gnu.org/viewcvs?rev=278720=gcc=rev
Log:
PR tree-optimization/92644
* tree-ssa-phiopt.c (minmax_replacement): Add INTEGRAL_TYPE_P check
next to INTEGER_CST checks.

* g++.dg/opt/pr92644.C: New test.

Added:
trunk/gcc/testsuite/g++.dg/opt/pr92644.C
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-ssa-phiopt.c

[Bug tree-optimization/92644] [9/10 Regression] ICE in wide_int_to_tree_1, at tree.c:1530

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92644

--- Comment #4 from Jakub Jelinek  ---
Created attachment 47350
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47350=edit
gcc10-pr92644.patch

Untested fix.

[Bug tree-optimization/92644] [9/10 Regression] ICE in wide_int_to_tree_1, at tree.c:1530

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92644

--- Comment #3 from Richard Biener  ---
INTEGRAL_TYPE_P

[Bug tree-optimization/92644] [9/10 Regression] ICE in wide_int_to_tree_1, at tree.c:1530

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92644

--- Comment #2 from Jakub Jelinek  ---
For pointers, it boils down whether say
void *
foo (void *p)
{
  return p ? p : (void *) 1;
}
optimization into MAX_EXPR <1B, p> is valid or not.  The original code doesn't
involve any non-equality comparisons, while MAX_EXPR is a non-equality
comparison which ought to be valid only as long as the two pointers are
pointing into the same object.  Another possibility would be for pointers to do
this optimization, but perform the MIN_EXPR/MAX_EXPR in pointer sized ints
instead.

So, the fix can be either NULLPTR_TYPE specific, like:
--- gcc/tree-ssa-phiopt.c   2019-11-20 09:25:42.552157763 +0100
+++ gcc/tree-ssa-phiopt.c   2019-11-24 18:56:50.657172109 +0100
@@ -1381,7 +1381,8 @@ minmax_replacement (basic_block cond_bb,

   /* Turn EQ/NE of extreme values to order comparisons.  */
   if ((cmp == NE_EXPR || cmp == EQ_EXPR)
-  && TREE_CODE (rhs) == INTEGER_CST)
+  && TREE_CODE (rhs) == INTEGER_CST
+  && TREE_CODE (TREE_TYPE (rhs)) != NULLPTR_TYPE)
 {
   if (wi::eq_p (wi::to_wide (rhs), wi::min_value (TREE_TYPE (rhs
{
@@ -1407,7 +1408,8 @@ minmax_replacement (basic_block cond_bb,
   larger = rhs;
   /* If we have smaller < CST it is equivalent to smaller <= CST-1.
 Likewise smaller <= CST is equivalent to smaller < CST+1.  */
-  if (TREE_CODE (larger) == INTEGER_CST)
+  if (TREE_CODE (larger) == INTEGER_CST
+ && TREE_CODE (TREE_TYPE (larger)) != NULLPTR_TYPE)
{
  if (cmp == LT_EXPR)
{
@@ -1435,7 +1437,8 @@ minmax_replacement (basic_block cond_bb,
   larger = gimple_cond_lhs (cond);
   /* If we have larger > CST it is equivalent to larger >= CST+1.
 Likewise larger >= CST is equivalent to larger > CST-1.  */
-  if (TREE_CODE (smaller) == INTEGER_CST)
+  if (TREE_CODE (smaller) == INTEGER_CST
+ && TREE_CODE (TREE_TYPE (larger)) != NULLPTR_TYPE)
{
  wi::overflow_type overflow;
  if (cmp == GT_EXPR)
or instead of it say && (INTEGRAL_TYPE_P (TREE_TYPE (rhs)) || POINTER_TYPE_P
(TREE_TYPE (rhs))), or just && INTEGRAL_TYPE_P (TREE_TYPE (rhs)), and if
allowing POINTER_TYPE_P, we can also special case
new_stmt = gimple_build_assign (result, minmax, arg0, arg1);
for pointers by casting to integers and back.
Thoughts?

[Bug tree-optimization/92644] [9/10 Regression] ICE in wide_int_to_tree_1, at tree.c:1530

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92644

Jakub Jelinek  changed:

   What|Removed |Added

 Status|UNCONFIRMED |ASSIGNED
   Last reconfirmed||2019-11-24
 CC||jakub at gcc dot gnu.org
   Assignee|unassigned at gcc dot gnu.org  |jakub at gcc dot gnu.org
   Target Milestone|--- |9.3
 Ever confirmed|0   |1

--- Comment #1 from Jakub Jelinek  ---
Started with r265909.
NULLPTR_TYPE only allows value 0, so doing
  rhs = wide_int_to_tree (TREE_TYPE (rhs),
  wi::min_value (TREE_TYPE (rhs)) + 1);
for it ICEs.
I'd say we should guard that only for INTEGRAL_TYPE_P types and perhaps
pointer/reference types too, though transformation of == NULL to < (void *) 1
looks really weird.