ping?
On Wed, Jun 6, 2012 at 2:04 PM, Roland McGrath <mcgra...@google.com> wrote:
> cf this change:
>
> 2010-11-19 Jakub Jelinek <ja...@redhat.com>
>
> PR target/45870
> * dwarf2out.c (const_ok_for_output_1): Don't complain about
> non-delegitimized TLS UNSPECs.
>
> This case hit me where the rtx was:
>
> (unspec:SI [
> (symbol_ref:SI ("*.LANCHOR0") [flags 0x1aa])
> (const_int 4 [0x4])
> ] UNSPEC_TLS)
>
> Note:
> 1. The UNSPEC has two operands, not one.
> 2. The SYMBOL_REF does not correspond to any decl.
>
> This corresponds to this ARM code:
>
> ldr r3, .L10+4
> ...
> .L10:
> <something else>
> .word .LANCHOR0(tpoff)
> ...
> .section .tdata,"awT",%progbits
> .align 4
> .LANCHOR0 = . + 0
> .type tdata1, %object
> .size tdata1, 4
> tdata1:
> .word 1
>
> The only way I know to reproduce this is using a variant ARM target that
> I'm still developing and is not yet ready to be submitted, so I don't have
> a proper test case to offer. But I think the principle of the following
> change is fairly sound.
>
> What do you think? (Recall that I am not a GCC committer, so if you like
> the change, please commit it for me.)
>
>
> Thanks,
> Roland
>
>
> 2012-06-06 Roland McGrath <mcgra...@google.com>
>
> * dwarf2out.c (const_ok_for_output_1): Detect a TLS UNSPEC using
> SYMBOL_REF_TLS_MODEL rather than DECL_THREAD_LOCAL_P, in case it's
> not a VAR_DECL. Also don't limit it to UNSPECs with exactly one
> operand.
>
> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
> index 6e4ab76..bc68205 100644
> --- a/gcc/dwarf2out.c
> +++ b/gcc/dwarf2out.c
> @@ -10129,12 +10129,12 @@ const_ok_for_output_1 (rtx *rtlp, void *data
> ATTRIBUTE_UNUSED)
> we can't express it in the debug info. */
> #ifdef ENABLE_CHECKING
> /* Don't complain about TLS UNSPECs, those are just too hard to
> - delegitimize. */
> - if (XVECLEN (rtl, 0) != 1
> + delegitimize. Note this could be a non-decl SYMBOL_REF such as
> + one in a constant pool entry, so testing SYMBOL_REF_TLS_MODEL
> + rather than DECL_THREAD_LOCAL_P is not just an optimization. */
> + if (XVECLEN (rtl, 0) == 0
> || GET_CODE (XVECEXP (rtl, 0, 0)) != SYMBOL_REF
> - || SYMBOL_REF_DECL (XVECEXP (rtl, 0, 0)) == NULL
> - || TREE_CODE (SYMBOL_REF_DECL (XVECEXP (rtl, 0, 0))) != VAR_DECL
> - || !DECL_THREAD_LOCAL_P (SYMBOL_REF_DECL (XVECEXP (rtl, 0, 0))))
> + || SYMBOL_REF_TLS_MODEL (XVECEXP (rtl, 0, 0)) == TLS_MODEL_NONE)
> inform (current_function_decl
> ? DECL_SOURCE_LOCATION (current_function_decl)
> : UNKNOWN_LOCATION,
