On Thu, Jan 24, 2019 at 8:28 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> As the following testcase shows, during var-tracking we can end trying to
> delegitimize e.g. (plus:SI (unspec:SI ... UNSPEC_SET_GOT)
> (const:SI (unspec:SI (symbol_ref:SI ...) UNSPEC_GOTOFF)). The code is
> prepared to handle PIC register + UNSPEC_GOTOFF, delegitimizing that
> to the underlying SYMBOL_REF, but we can end up with the UNSPEC_SET_GOT
> instead of the %ebx etc. register, because in the RTL that register
> is initialized to that UNSPEC_SET_GOT.
>
> The following patch handles it like the pic register; the
> ix86_pic_register_p function is used only in the delegitimization hook.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, the patch removed
> all 170 non-delegitimized UNSPEC messages from x86_64-linux bootstrap and
> 142 out of 144 non-delegitimized UNSPEC messages from i686-linux bootstrap,
> ok for trunk?
>
> 2019-01-24 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/89006
> * config/i386/i386.c (ix86_pic_register_p): Return true for
> UNSPEC_SET_GOT too.
>
> * g++.dg/debug/pr89006.C: New test.
LGTM.
Thanks,
Uros.
> --- gcc/config/i386/i386.c.jj 2019-01-22 23:26:46.668212957 +0100
> +++ gcc/config/i386/i386.c 2019-01-24 11:51:40.050801078 +0100
> @@ -16972,6 +16972,8 @@ ix86_pic_register_p (rtx x)
> if (GET_CODE (x) == VALUE && CSELIB_VAL_PTR (x))
> return (pic_offset_table_rtx
> && rtx_equal_for_cselib_p (x, pic_offset_table_rtx));
> + else if (GET_CODE (x) == UNSPEC && XINT (x, 1) == UNSPEC_SET_GOT)
> + return true;
> else if (!REG_P (x))
> return false;
> else if (pic_offset_table_rtx)
> --- gcc/testsuite/g++.dg/debug/pr89006.C.jj 2019-01-24 12:18:59.119838677
> +0100
> +++ gcc/testsuite/g++.dg/debug/pr89006.C 2019-01-24 12:16:56.642859109
> +0100
> @@ -0,0 +1,20 @@
> +// PR debug/89006
> +// { dg-do compile }
> +// { dg-options "-O2 -g -w" }
> +// { dg-additional-options "-fPIC" { target fpic } }
> +// { dg-bogus "non-delegitimized UNSPEC UNSPEC_SET_GOT" "" { target {
> i?86-*-* x86_64-*-* } } 0 }
> +
> +struct A { A (bool); };
> +
> +static void
> +foo (const char *x)
> +{
> + new A (x);
> +}
> +
> +void
> +bar ()
> +{
> + foo ("foo");
> + foo ("bar");
> +}
>
> Jakub
