On April 4, 2017 9:29:19 PM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>When I've implemented vector -fsanitize=signed-integer-overflow,
>we've started to emit weirdo warnings on e.g. the following testcase.
>
>There is really no call with return value that changes ABI
>based on ISA options, there is just an internal fn call that is
>expanded
>completely inline (UBSAN_CHECK_*), but as the NRV pass calls
>aggregate_value_p even on those internal functions, we get the warning.
>
>The following patch keeps doing that for internal functions that have
>corresponding optab, those typically have a library counterpart, but
>for others that really don't have one and are always expanded inline
>avoids calling aggregate_value_p, we really can't NRV optimize those
>internal fns anyway.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
>2017-04-04 Jakub Jelinek <ja...@redhat.com>
>
> PR target/80310
> * tree-nvr.c: Include internal-fn.h.
> (pass_return_slot::execute): Ignore internal calls without
> direct optab.
>
> * c-c++-common/ubsan/pr80310.c: New test.
>
>--- gcc/tree-nrv.c.jj 2017-01-01 12:45:39.000000000 +0100
>+++ gcc/tree-nrv.c 2017-04-04 15:51:54.864211786 +0200
>@@ -28,6 +28,7 @@ along with GCC; see the file COPYING3.
> #include "tree-pretty-print.h"
> #include "gimple-iterator.h"
> #include "gimple-walk.h"
>+#include "internal-fn.h"
>
> /* This file implements return value optimizations for functions which
> return aggregate types.
>@@ -377,6 +378,12 @@ pass_return_slot::execute (function *fun
> if (stmt
> && gimple_call_lhs (stmt)
> && !gimple_call_return_slot_opt_p (stmt)
>+ /* Ignore internal functions without direct optabs,
>+ those are expanded specially and aggregate_value_p
>+ on their result might result in undesirable warnings
>+ with some backends. */
>+ && (!gimple_call_internal_p (stmt)
>+ || direct_internal_fn_p (gimple_call_internal_fn (stmt)))
> && aggregate_value_p (TREE_TYPE (gimple_call_lhs (stmt)),
> gimple_call_fndecl (stmt)))
> {
>--- gcc/testsuite/c-c++-common/ubsan/pr80310.c.jj 2017-04-04
>16:13:35.108407423 +0200
>+++ gcc/testsuite/c-c++-common/ubsan/pr80310.c 2017-04-04
>16:12:24.000000000 +0200
>@@ -0,0 +1,12 @@
>+/* PR target/80310 */
>+/* { dg-do compile } */
>+/* { dg-options "-O2 -fsanitize=signed-integer-overflow" } */
>+/* { dg-additional-options "-mno-avx" { target i?86-*-* x86_64-*-* } }
>*/
>+
>+typedef int V __attribute__((vector_size (32)));
>+
>+void
>+foo (V *a, V *b, V *c)
>+{
>+ *a = *b + *c; /* { dg-bogus "AVX vector return without AVX
>enabled
>changes the ABI" "" { target i?86-*-* x86_64-*-* } } */
>+}
>
> Jakub
