| Summary: | [4.3 Regression] tree check: expected ssa_name, have struct_field_tag in vuses_compare, at tree-vn.c:118 | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Richard Biener <rguenth> |
| Component: | middle-end | Assignee: | Not yet assigned to anyone <unassigned> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | gcc-bugs |
| Priority: | P3 | Keywords: | alias, ice-on-valid-code |
| Version: | 4.3.0 | ||
| Target Milestone: | 4.3.0 | ||
| Host: | Target: | ||
| Build: | Known to work: | ||
| Known to fail: | Last reconfirmed: | ||
| Attachments: | patch | ||
|
Description
Richard Biener
2007-12-14 12:40:20 UTC
On ppc, the following ICEs compiled with -O2 during PRE
typedef __builtin_va_list va_list;
void gftp_config_parse_args (int numargs, char **first, ...)
{
char **dest = first;
va_list argp;
__builtin_va_start (argp, first);
while (numargs-- > 0)
{
*dest = __builtin_malloc (1);
dest = __builtin_va_arg(argp, char **);
*dest = ((void *)0);
}
__builtin_va_end(argp);
}
Created attachment 14753 [details]
patch
The problem is that the operand scanner is triggered on a fake store inserted
by PRE insert_fake_stores() as if a new stmt_ann is generated, the stmt is
marked modified and bsi_insert_after() will update the stmts operands in this
case.
For some reason this figures new, unrenamed virtual operands:
# VUSE <SFT.2_69, SFT.3_70, SFT.4, SFT.5, SFT.6, SMT.15_71> { SFT.2 SFT.3 SFT.4 SFT.5 SFT.6 SMT.15 }
storetmp.19_3 = *dest_22
which triggers this ICE.
So, I believe we should not re-build operands for this stmt, as we carefuly
use create_ssa_artificial_load_stmt () to do so. In fact, this will make
the following part of that function non-effective:
/* All uses in this fake stmt must not be in the immediate use lists. */
FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
delink_imm_use (use_p);
BUT - this patch causes a whole lot of new problems because suddenly VN_TOP
starts to leak into virtual operands which causes bootstrap to fail on
x86_64 building bid_decimal_globals.c for 32bit.
Which is of course because SCCVN does not like this sort of "broken" immediate uses! Subject: Bug 34462 Author: rguenth Date: Fri Dec 14 14:21:41 2007 New Revision: 130931 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130931 Log: 2007-12-14 Richard Guenther <rguenther@suse.de> PR middle-end/34462 * tree-ssa-operands.h (create_ssa_artificial_load_stmt): Add parameter to say whether to unlink immediate uses. * tree-ssa-operands.c (create_ssa_artificial_load_stmt): Do not mark the artificial stmt as modified. Unlink immediate uses only if requested. * tree-ssa-dom.c (record_equivalences_from_stmt): Update caller. * tree-ssa-pre.c (insert_fake_stores): Likewise. * gcc.c-torture/compile/20071214-1.c: New testcase. Added: trunk/gcc/testsuite/gcc.c-torture/compile/20071214-1.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-ssa-dom.c trunk/gcc/tree-ssa-operands.c trunk/gcc/tree-ssa-operands.h trunk/gcc/tree-ssa-pre.c Fixed. |