https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112674
Bug ID: 112674
Summary: [14 Regression] Compare-debug failure after recent
change on c6x
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: law at gcc dot gnu.org
Target Milestone: ---
This patch:
commit 6bf66276e3e41d5d92f7b7260e98b6a111653805
Author: Richard Biener <rguent...@suse.de>
Date: Wed Nov 22 11:10:41 2023 +0100
tree-optimization/112344 - wrong final value replacement
When performing final value replacement chrec_apply that's used to
compute the overall effect of niters to a CHREC doesn't consider that
the overall increment of { -2147483648, +, 2 } doesn't fit in
a signed integer when the loop iterates until the value of the IV
of 20. The following fixes this mistake, carrying out the multiply
and add in an unsigned type instead, avoiding undefined overflow
and thus later miscompilation by path range analysis.
PR tree-optimization/112344
* tree-chrec.cc (chrec_apply): Perform the overall increment
calculation and increment in an unsigned type.
* gcc.dg/torture/pr112344.c: New testcase.
Is causing a compare-debug failure on the c6x port:
c6x-sim: gcc.dg/pr65779.c (test for excess errors)
I haven't dug into this any deeper. It could well be a c6x bug in the end.
While it may sound similar to pr109777, pr109777 has been debugged far enough
to lay the blame on the bfin backend.
