From: Sergei Trofimovich <siarh...@google.com>
TOPN metrics are histograms that contain overall count and per-bucket
count. Overall count can be nevative when two profiles merge and some
of per-bucket metrics are dropped.
Noticed as an ICE on python PGO build where gcc crashes as:
during IPA pass: modref
a.c:36:1: ICE: in stream_out_histogram_value, at value-prof.cc:340
36 | }
| ^
stream_out_histogram_value(output_block*, histogram_value_t*)
gcc/value-prof.cc:340
gcc/ChangeLog:
PR gcov-profile/105282
* value-prof.cc (stream_out_histogram_value): Allow negavive counts
on HIST_TYPE_INDIR_CALL.
---
gcc/value-prof.cc | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/gcc/value-prof.cc b/gcc/value-prof.cc
index 9785c7a03ea..4927d119aa0 100644
--- a/gcc/value-prof.cc
+++ b/gcc/value-prof.cc
@@ -319,40 +319,44 @@ stream_out_histogram_value (struct output_block *ob,
histogram_value hist)
streamer_write_bitpack (&bp);
switch (hist->type)
{
case HIST_TYPE_INTERVAL:
streamer_write_hwi (ob, hist->hdata.intvl.int_start);
streamer_write_uhwi (ob, hist->hdata.intvl.steps);
break;
default:
break;
}
for (i = 0; i < hist->n_counters; i++)
{
/* When user uses an unsigned type with a big value, constant converted
to gcov_type (a signed type) can be negative. */
gcov_type value = hist->hvalue.counters[i];
if (hist->type == HIST_TYPE_TOPN_VALUES
|| hist->type == HIST_TYPE_IOR)
/* Note that the IOR counter tracks pointer values and these can have
sign bit set. */
;
+ else if (hist->type == HIST_TYPE_INDIR_CALL && i == 0)
+ /* 'all' counter overflow is stored as a negative value. Individual
+ counters and values are expected to be non-negative. */
+ ;
else
gcc_assert (value >= 0);
streamer_write_gcov_count (ob, value);
}
if (hist->hvalue.next)
stream_out_histogram_value (ob, hist->hvalue.next);
}
/* Dump information about HIST to DUMP_FILE. */
void
stream_in_histogram_value (class lto_input_block *ib, gimple *stmt)
{
enum hist_type type;
unsigned int ncounters = 0;
struct bitpack_d bp;
unsigned int i;
histogram_value new_val;
bool next;
--
2.35.1
