On Sat, 25 Feb 2017, Jakub Jelinek wrote:
> On Sat, Feb 25, 2017 at 08:42:33AM +0100, Richard Biener wrote:
> > On February 24, 2017 9:56:25 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
> > wrote:
> > >Hi!
> > >
> > >On the following testcase we replace a PLUS_EXPR (which is considered
> > >throwing with -fnon-call-exceptions when it has floating point
> > >arguments
> > >and FP exceptions or sNaNs are enabled) with a FMA_EXPR; I believe it
> > >can throw the same, but stmt_could_throw_1_p doesn't think so (as it is
> > >not unary/binary/comparison). While we could tweak the widen_mul patch
> > >to deal with dropping EH from gsi_replace and cleaning up cfg etc., I
> > >believe the right fix is to fix stmt_could_throw_1_p.
> > >
> > >Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
> >
> > OK. Can you make sure this is then consistent with the other throw
> > predicates?.
>
> may_trap_p_1 handles FMA right, no idea what other predicates could cover
> that on RTL. But you're right, operation_could_trap_p used by
> tree_could_trap_p needs the same treatment:
Yes, that was what I remembered (used for example by vn_nary_may_trap).
Ok.
Thanks,
Richard.
> 2017-02-25 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/79396
> * tree-eh.c (operation_could_trap_p, stmt_could_throw_1_p): Handle
> FMA_EXPR like tcc_binary or tcc_unary.
>
> * g++.dg/opt/pr79396.C: New test.
>
> --- gcc/tree-eh.c.jj 2017-02-24 21:39:01.240088691 +0100
> +++ gcc/tree-eh.c 2017-02-25 09:21:06.017859379 +0100
> @@ -2513,7 +2513,8 @@ operation_could_trap_p (enum tree_code o
>
> if (TREE_CODE_CLASS (op) != tcc_comparison
> && TREE_CODE_CLASS (op) != tcc_unary
> - && TREE_CODE_CLASS (op) != tcc_binary)
> + && TREE_CODE_CLASS (op) != tcc_binary
> + && op != FMA_EXPR)
> return false;
>
> return operation_could_trap_helper_p (op, fp_operation, honor_trapv,
> @@ -2738,7 +2739,8 @@ stmt_could_throw_1_p (gimple *stmt)
>
> if (TREE_CODE_CLASS (code) == tcc_comparison
> || TREE_CODE_CLASS (code) == tcc_unary
> - || TREE_CODE_CLASS (code) == tcc_binary)
> + || TREE_CODE_CLASS (code) == tcc_binary
> + || code == FMA_EXPR)
> {
> if (is_gimple_assign (stmt)
> && TREE_CODE_CLASS (code) == tcc_comparison)
> --- gcc/testsuite/g++.dg/opt/pr79396.C.jj 2017-02-25 09:20:03.608706718
> +0100
> +++ gcc/testsuite/g++.dg/opt/pr79396.C 2017-02-25 09:20:03.607706732
> +0100
> @@ -0,0 +1,13 @@
> +// PR middle-end/79396
> +// { dg-do compile }
> +// { dg-options "-fnon-call-exceptions -O2" }
> +// { dg-additional-options "-mfma" { target i?86-*-* x86_64-*-* } }
> +
> +struct A { A (); ~A (); };
> +
> +float
> +foo (float x)
> +{
> + A a;
> + return __builtin_pow (x, 2) + 2;
> +}
>
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
