[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 Jakub Jelinek changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org --- Comment #7 from Jakub Jelinek --- Fixed.
[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 --- Comment #6 from Jakub Jelinek --- Author: jakub Date: Fri Apr 6 11:24:36 2018 New Revision: 259167 URL: https://gcc.gnu.org/viewcvs?rev=259167=gcc=rev Log: PR sanitizer/85213 * fold-const.c (twoval_comparison_p): Remove SAVE_P argument and don't look through SAVE_EXPRs with non-side-effects argument. Adjust recursive calls. (fold_comparison): Adjust twoval_comparison_p caller, don't handle save_p here. * c-c++-common/ubsan/pr85213.c: New test. Added: trunk/gcc/testsuite/c-c++-common/ubsan/pr85213.c Modified: trunk/gcc/ChangeLog trunk/gcc/fold-const.c trunk/gcc/testsuite/ChangeLog
[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 --- Comment #5 from Jakub Jelinek --- unshare_expr doesn't unshare the STATEMENT_LISTs embedded inside of it (and wonder what would Alex' code do if we have two separate DEBUG_BEGIN_STMTs for the same statement).
[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 --- Comment #4 from Richard Biener --- (In reply to Jakub Jelinek from comment #3) > The problem is that twoval_comparison_p breaks appart SAVE_EXPR if their > argument has no side effects. > First, cp_build_binary_op calls save_expr on: > (__builtin_expect ((long int) (# DEBUG BEGIN STMT; > x != 0; ? 0 : 1), (long int) NON_LVALUE_EXPR <3>) == 0) * -1; > and that resulting SAVE_EXPR is used in 2+ places, where one of them is a > comparison against INTEGER_CST, which is optimized using twoval_comparison_p > as > another SAVE_EXPR with > __builtin_expect ((long int) (# DEBUG BEGIN STMT; > x != 0; ? 0 : 1), (long int) NON_LVALUE_EXPR <3>) == 0; > body. As mostly_copy_tree_r does not unshare STATEMENT_LISTs, we hand over > to the gimplifier the above two SAVE_EXPRs and both contain the same > STATEMENT_LIST, so we try to gimplify it twice, which as we know from other > PRs doesn't really work at all. > Now, not looking through SAVE_EXPRs in twoval_comparison_p if it contains a > STATEMENT_LIST might result in -fcompare-debug failures, because with -g0 > there could be no STATEMENT_LIST, while with -g we have one. > Not sure what our options are, besides just killing the SAVE_EXPR handling > in twoval_comparison_p. unshare the expression in twoval_comparison_p?
[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 Jakub Jelinek changed: What|Removed |Added Status|ASSIGNED|NEW CC||aoliva at gcc dot gnu.org Assignee|jakub at gcc dot gnu.org |unassigned at gcc dot gnu.org --- Comment #3 from Jakub Jelinek --- The problem is that twoval_comparison_p breaks appart SAVE_EXPR if their argument has no side effects. First, cp_build_binary_op calls save_expr on: (__builtin_expect ((long int) (# DEBUG BEGIN STMT; x != 0; ? 0 : 1), (long int) NON_LVALUE_EXPR <3>) == 0) * -1; and that resulting SAVE_EXPR is used in 2+ places, where one of them is a comparison against INTEGER_CST, which is optimized using twoval_comparison_p as another SAVE_EXPR with __builtin_expect ((long int) (# DEBUG BEGIN STMT; x != 0; ? 0 : 1), (long int) NON_LVALUE_EXPR <3>) == 0; body. As mostly_copy_tree_r does not unshare STATEMENT_LISTs, we hand over to the gimplifier the above two SAVE_EXPRs and both contain the same STATEMENT_LIST, so we try to gimplify it twice, which as we know from other PRs doesn't really work at all. Now, not looking through SAVE_EXPRs in twoval_comparison_p if it contains a STATEMENT_LIST might result in -fcompare-debug failures, because with -g0 there could be no STATEMENT_LIST, while with -g we have one. Not sure what our options are, besides just killing the SAVE_EXPR handling in twoval_comparison_p.
[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 Jakub Jelinek changed: What|Removed |Added Priority|P3 |P1 Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek --- I'll handle this.
[Bug sanitizer/85213] [8 Regression] -fsanitize=undefined internal compiler error: in fold_convert_loc, at fold-const.c:2402
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85213 Marek Polacek changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2018-04-04 CC||mpolacek at gcc dot gnu.org Target Milestone|--- |8.0 Summary|-fsanitize=undefined|[8 Regression] |internal compiler error: in |-fsanitize=undefined |fold_convert_loc, at|internal compiler error: in |fold-const.c:2402 |fold_convert_loc, at ||fold-const.c:2402 Ever confirmed|0 |1 --- Comment #1 from Marek Polacek --- Started with r255947.
