[Bug tree-optimization/85588] [6/7/8/9 Regression] -fwrapv miscompilation

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85588

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Or rather

Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c    (revision 259879)
+++ gcc/fold-const.c    (working copy)
@@ -474,12 +474,15 @@ negate_expr_p (tree t)
     case EXACT_DIV_EXPR:
       if (TYPE_UNSIGNED (type))
        break;
-      if (negate_expr_p (TREE_OPERAND (t, 0)))
+      /* In general we can't negate A in A / B, because if A is INT_MIN and
+         B is not 1 we change the sign of the result.  */
+      if (TREE_CODE (TREE_OPERAND (t, 0)) == INTEGER_CST
+         && negate_expr_p (TREE_OPERAND (t, 0)))
        return true;
       /* In general we can't negate B in A / B, because if A is INT_MIN and
         B is 1, we may turn this into INT_MIN / -1 which is undefined