On 11/05/13 22:24, Ian Lance Taylor wrote:
On Mon, Nov 4, 2013 at 5:57 PM, Jeff Law <l...@redhat.com> wrote:
* Makefile.in (OBJS): Add gimple-ssa-isolate-paths.o
* common.opt (-fisolate-erroneous-paths): Add option and
documentation.
* gimple-ssa-isolate-paths.c: New file.
* gimple.c (check_loadstore): New function.
(infer_nonnull_range): Moved into gimple.c from tree-vrp.c
Verify OP is in the argument list and the argument corresponding
to OP is a pointer type. Use operand_equal_p rather than
pointer equality when testing if OP is on the nonnull list.
Use check_loadstore rather than count_ptr_derefs. Handle
GIMPLE_RETURN statements.
* tree-vrp.c (infer_nonnull_range): Remove.
* gimple.h (infer_nonnull_range): Declare.
* opts.c (default_options_table): Add OPT_fisolate_erroneous_paths.
* passes.def: Add pass_isolate_erroneous_paths.
* timevar.def (TV_ISOLATE_ERRONEOUS_PATHS): New timevar.
* tree-pass.h (make_pass_isolate_erroneous_paths): Declare.
* tree-ssa.c (struct count_ptr_d): Remove.
(count_ptr_derefs, count_uses_and_derefs): Remove.
* tree-ssa.h (count_uses_and_derefs): Remove.
* gcc.dg/pr38984.c: Add -fno-isolate-erroneous-paths.
* gcc.dg/tree-ssa/isolate-1.c: New test.
* gcc.dg/tree-ssa/isolate-2.c: New test.
* gcc.dg/tree-ssa/isolate-3.c: New test.
* gcc.dg/tree-ssa/isolate-4.c: New test.
This patch actually breaks the Go testsuite. In Go dereferencing a
nil pointer is well-defined: it causes panic that can be caught. This
breaks a test for that functionality by changing the panic to a
builtin_trap.
That's not a big deal; I'll just disable this optimization in the Go
frontend.
That's certainly the right thing to do. Sorry, I don't have Go enabled
so I didn't catch it.
What I'm really writing about is that it seems to me that there should
be some docs for this new option in gcc/doc/invoke.texi. I don't see
any.
Sigh. I'll take care of that oversight.
jeff
