On Thu, 21 Mar 2019, Richard Biener wrote: > > This also avoids the ICE in PR89779 but IMHO is not a real fix. > > Still it restores a previously active check against released SSA names > which now have error_mark_node type rather than NULL. The new way > opens up consolidation so I've adjusted tree_nop_conversion plus > operand_equal_p which got a defensive check at the same time > (and checks for error_mark_node right before that check). > > Bootstrap & regtest running on x86_64-unknown-linux-gnu. > > The testcase comes with the other patch (but still included below).
Ugh, looks like my defense installed for released SSA names is now relied upon by the C++ FE via #2 0x0000000001864a96 in tree_strip_nop_conversions ( exp=<convert_expr 0x7ffff69bc920>) at /space/rguenther/src/svn/trunk2/gcc/tree.c:12848 #3 0x0000000000ab2d2f in iterative_hash_template_arg ( arg=<convert_expr 0x7ffff69bc920>, val=3363282904) at /space/rguenther/src/svn/trunk2/gcc/cp/pt.c:1751 for <convert_expr 0x7ffff69bc920 type <integer_type 0x7ffff68985e8 int public type_6 SI size <integer_cst 0x7ffff689c078 constant 32> unit-size <integer_cst 0x7ffff689c090 constant 4> align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x7ffff68985e8 precision:32 min <integer_cst 0x7ffff689c030 -2147483648> max <integer_cst 0x7ffff689c048 2147483647> pointer_to_this <pointer_type 0x7ffff68a19d8>> arg:0 <scope_ref 0x7ffff69d0b40 tree_0 arg:0 <template_type_parm 0x7ffff69d17e0 i tree_0 type_0 type_6 VOID align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x7ffff69d1150 index 0 level 1 orig_level 1 chain <type_decl 0x7ffff69d2098 i>> arg:1 <identifier_node 0x7ffff69c39c0 c normal local bindings <(nil)>>>> where both the SCOPE_REF and TEMPLATE_TYPE_PARM have NULL TREE_TYPE. So I'll restore the NULL check in tree_nop_conversion. But since the C++ FE overloads almost every tree field possible I wonder whether that STRIP_NOPS in iterative_hash_template_arg is a good idea? Also I hope the FE doesn't call into operand_equal_p with such typed trees. Updated patch below, retesting now. Thanks, Richard. 2019-03-21 Richard Biener <rguent...@suse.de> PR tree-optimization/89779 * tree.c (tree_nop_conversion): Consolidate and fix defensive checks with respect to released SSA names now having error_mark_node type. * fold-const.c (operand_equal_p): Likewise. Index: gcc/tree.c =================================================================== --- gcc/tree.c (revision 269832) +++ gcc/tree.c (working copy) @@ -12812,13 +12812,10 @@ tree_nop_conversion (const_tree exp) if (!CONVERT_EXPR_P (exp) && TREE_CODE (exp) != NON_LVALUE_EXPR) return false; - if (TREE_OPERAND (exp, 0) == error_mark_node) - return false; outer_type = TREE_TYPE (exp); inner_type = TREE_TYPE (TREE_OPERAND (exp, 0)); - - if (!inner_type) + if (!inner_type || inner_type == error_mark_node) return false; return tree_nop_conversion_p (outer_type, inner_type); Index: gcc/fold-const.c =================================================================== --- gcc/fold-const.c (revision 269832) +++ gcc/fold-const.c (working copy) @@ -2973,11 +2973,6 @@ operand_equal_p (const_tree arg0, const_ || TREE_TYPE (arg1) == error_mark_node) return 0; - /* Similar, if either does not have a type (like a released SSA name), - they aren't equal. */ - if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1)) - return 0; - /* We cannot consider pointers to different address space equal. */ if (POINTER_TYPE_P (TREE_TYPE (arg0)) && POINTER_TYPE_P (TREE_TYPE (arg1)) Index: gcc/testsuite/gcc.dg/torture/pr89779.c =================================================================== --- gcc/testsuite/gcc.dg/torture/pr89779.c (nonexistent) +++ gcc/testsuite/gcc.dg/torture/pr89779.c (working copy) @@ -0,0 +1,20 @@ +/* { dg-do compile } */ + +typedef int a; +void h(a); +void c(a *d, int b) +{ + int e, f, g; + for (; e; e++) + for (f = 0; f < 4; f++) + if (d) + for (g = e + 1; g; g++) + h(d[g]); +} +void i() +{ + a *j; + int k, l; + for (; k; k++) + c(j, l); +}