On 05/02/13 11:12, Jakub Jelinek wrote:
> On Tue, Feb 05, 2013 at 11:01:22AM +0100, Tom de Vries wrote:
>> I'm not sure I understand your comment.
>>
>> The BLOCK_FOR_INSN of the note was NULL. The NOTE_BASIC_BLOCK of the note was
>> correct. Are you saying that the BLOCK_FOR_INSN should not have been NULL?
>
> Yeah, I mean the following invariant should hold IMHO:
> !NOTE_INSN_BASIC_BLOCK_P (insn) || NOTE_BASIC_BLOCK (insn) == BLOCK_FOR_INSN
> (insn)
> NOTE_INSN_BASIC_BLOCK for some bb outside of that bb? That looks fishy.
> Haven't bootstrapped/regtested with such a check anywhere, just compiled one
> largish C++ testcase with it.
>
Jakub,
I've used patch below to print rtl with a BLOCK_FOR_INSN annotation, and looked
at behaviour for x86_64 and sparc.
For sparc, BLOCK_FOR_INSN is always NULL starting at pass_mach dump files, due
to pass_free_cfg that calls free_bb_for_insn, whose only purpose is to set the
BLOCK_FOR_INSN field to NULL.
So all NOTE_INSN_BASIC_BLOCKs in the .mach dump and after violate the invariant
formulated above:
...
[bfi NULL](note 13 8 201 [bb 2] NOTE_INSN_BASIC_BLOCK)
...
For x86_64, we recompute BLOCK_FOR_INSN in pass_mach here:
...
static void
ix86_reorg (void)
{
/* We are freeing block_for_insn in the toplev to keep compatibility
with old MDEP_REORGS that are not CFG based. Recompute it now. */
compute_bb_for_insn ();
...
so we have BLOCK_FOR_INSN all the way till pass_final.
The PR56131 ICE occurred for sparc in pass_delay_slots, after pass_mach, so it's
expected that BLOCK_FOR_INSN is NULL.
Thanks,
- Tom
Index: gcc/print-rtl.c
===================================================================
--- gcc/print-rtl.c (revision 195747)
+++ gcc/print-rtl.c (working copy)
@@ -800,6 +800,20 @@ print_rtl_single_with_indent (FILE *outf
sawclose = 0;
fputs (s_indent, outfile);
fputs (print_rtx_head, outfile);
+#ifndef GENERATOR_FILE
+ {
+ basic_block bb;
+ if (GET_RTX_LENGTH (GET_CODE (x)) >= 4
+ && GET_RTX_FORMAT (GET_CODE (x))[3] == 'B')
+ {
+ bb = BLOCK_FOR_INSN (x);
+ if (bb != 0)
+ fprintf (outfile, " [bfi %d]", bb->index);
+ else
+ fprintf (outfile, " [bfi NULL]");
+ }
+ }
+#endif
