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Re: [PATCH] PR rtl-optimization/32219: optimizer causees wrong code in pic/hidden/weak symbol checking
- From: Uros Bizjak <ubizjak at gmail dot com>
- To: Richard Henderson <rth at redhat dot com>
- Cc: "H.J. Lu" <hjl dot tools at gmail dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 19 Feb 2015 22:04:50 +0100
- Subject: Re: [PATCH] PR rtl-optimization/32219: optimizer causees wrong code in pic/hidden/weak symbol checking
- Authentication-results: sourceware.org; auth=none
- References: <CAFULd4Z4XH0TwZopQb8nXOfv08L2-cXFdPpPAN2uRpTHFtTGfg at mail dot gmail dot com> <CAMe9rOqwGccCzB-W8nYgzc6JL2O6kx0vkS07xOK+oa4bimHgiw at mail dot gmail dot com> <54E21B33 dot 8020905 at redhat dot com>
On Mon, Feb 16, 2015 at 5:30 PM, Richard Henderson <rth@redhat.com> wrote:
>>>> 2015-02-12 H.J. Lu <hongjiu.lu@intel.com>
>>>> Richard Henderson <rth@redhat.com>
>>>>
>>>> PR rtl/32219
>>>> * cgraphunit.c (cgraph_node::finalize_function): Set definition
>>>> before notice_global_symbol.
>>>> (varpool_node::finalize_decl): Likewise.
>>>> * varasm.c (default_binds_local_p_2): Rename from
>>>> default_binds_local_p_1, add weak_dominate argument. Use direct
>>>> returns instead of assigning to local variable. Unify varpool and
>>>> cgraph paths via symtab_node. Reject undef weak variables before
>>>> testing visibility. Reorder tests for simplicity.
>>>> (default_binds_local_p): Use default_binds_local_p_2.
>>>> (default_binds_local_p_1): Likewise.
>>>> (decl_binds_to_current_def_p): Unify varpool and cgraph paths
>>>> via symtab_node.
>>>> (default_elf_asm_output_external): Emit visibility when specified.
>>>
>>> It looks like this patch broke alphaev68-linux-gnu [1]. There are many
>>> failures of the type:
>>>
>>> /tmp/cck7V7MR.o: In function
>>> `__static_initialization_and_destruction_0(int, int)':^M
>>> (.text+0x3ac): relocation truncated to fit: GPRELHIGH against symbol
>>> `std::__cxx11::basic_string<char, std::char_traits<char>,
>>> std::allocator<char> >::~basic_string()@@GLIBCXX_3.4.21' defined in
>>> .text section in
>>> /space/uros/gcc-build/alphaev68-unknown-linux-gnu/./libstdc++-v3/src/.libs/libstdc++.so^M
>>> /space/homedirs/uros/local/bin/ld: /tmp/cck7V7MR.o: gp-relative
>>> relocation against dynamic symbol
>>
>> It could be related to:
>>
>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65064
>>
>> Before this bug fix, all common symbols don't bind locally,
>> which is one of PR 32219 bugs. After this fix, common
>> symbols bind locally. It may cause problems on targets with
>> small data sections and common symbols aren't in small
>> data section:
>
> This is a destructor, and so obviously not a common symbol.
>
> I'll have a look.
The attached patch fixes all alpha-linux-gnu failures.
2015-02-19 Uros Bizjak <ubizjak@gmail.com>
* config/alpha/alpha.c (alpha_in_small_data_p): Reject common symbols.
Patch was bootstrapped and regression tested on alphaev68-linux-gnu.
OK for mainline?
Uros.
Index: config/alpha/alpha.c
===================================================================
--- config/alpha/alpha.c (revision 220806)
+++ config/alpha/alpha.c (working copy)
@@ -835,6 +835,10 @@ alpha_in_small_data_p (const_tree exp)
if (TREE_CODE (exp) == FUNCTION_DECL)
return false;
+ /* COMMON symbols are never small data. */
+ if (TREE_CODE (exp) == VAR_DECL && DECL_COMMON (exp))
+ return false;
+
if (TREE_CODE (exp) == VAR_DECL && DECL_SECTION_NAME (exp))
{
const char *section = DECL_SECTION_NAME (exp);