Re: icf_safe_test in gold fails with gcc-4.0.3

[Sriraman Tallam <tmsriram at google dot com>]

Hi,

   Here is a patch to allow ICF to fold .gnu.linkonce.t sections.

	* gc.h (gc_process_relocs): Call is_section_foldable_candidate to
	check for .text or .gnu.linkonce.t sections.
	* icf.cc (Icf::find_identical_sections): Ditto.
	Change the detection for mangled function name within the section
	name.
	* icf.h (is_section_foldable_candidate): New function.

Please let me know what you think.

Thanks,
-Sri.


On Tue, Dec 29, 2009 at 7:14 PM, Ian Lance Taylor <iant@google.com> wrote:
> Sriraman Tallam <tmsriram@google.com> writes:
>
>> ? ?With gcc-4.0.3, icf_safe_test fails.
>>
>> Safe Identical Code Folding did not fold ?_ZN1AD1Ev and _ZN1AC1Ev
>> FAIL: icf_safe_test.sh
>>
>> This is because gcc-4.0.3 puts constructors and destructors in
>> .gnu.linkonce.t sections whereas gcc-4.4, on which ICF was tested,
>> puts them in .text sections. I can modify ICF to also fold
>> .gnu.linkonce.t sections and that should solve the problem. Would this
>> be alright ?
>
> Folding .gnu.linkonce sections should be fine. ?Don't get confused by
> the fact that duplicate .gnu.linkonce sections with the same names are
> discarded. ?.gnu.linkonce is the old mechanism which is now done using
> SHT_GROUP.
>
> Ian
>

Attachment: gold_icf_patch.txt
Description: Text document